experimental - shodhgangashodhganga.inflibnet.ac.in/bitstream/10603/8023/8/08_chapter 3.pdfdiethyl...

23

Experimental

Electrochemical reactions of various types of organic compounds

have been carried out at sacrificial bismuth anode and inert platinum

cathode. For the sake of convenience the experimental work has been

described under the following parts:

Part (A): Reagents, their purification and apparatus.

Part (B): Electrochemical synthesis and isolation of Bismuth

Compounds.

Part (C): Procedure for chemical analysis and determination of current

efficiencies.

24

PART (A)

Reagents, their Purification and Apparatus

Acetone:-

Acetone was purified by adding a solution of silver nitrate (3.0 g

in 20 mL of distilled water) and 20 mL of normal sodium hydroxide in

700 mL of acetone. This mixture was shaken for ten minutes, filtered,

dried over anhydrous calcium chloride and distilled. The fraction coming

out at 56.0˚ C and 740 mm and collected178.

Acetonitrile:-

Acetonitrile was kept over phosphorus pentoxide for twenty-four

hours and was distilled over it and then was fraction distilled178

at

80.0˚C.

Diethyl ether:-

Diethyl ether of analytical reagent grade was refluxed with

sodium metal for twenty-four hours. It was then fractional distilled at

34.0˚ C keeping it over sodium wire178.

Tetrabutylammonium Chloride:-

Tetrabutylammonium Chloride was crystallized twice from

conductivity water, and then crystals were dried under vacuum at

100˚C.

Methanol:-

Methanol was distilled over sodium metal and the distillate was

treated with pure and dry magnesium metal and with small amount of

25

iodine under reflux. It was allowed to stand for two hours and then it

was distilled at 64.3˚ C and 740 mm and collected178.

Ethanol:-

Ethanol was kept over quick lime for twenty-four hours and then

decanted off. It was refluxed over fresh quick lime for two hours followed

by distillation. It was then redistilled over sodium metal and fractional

distilled at 78˚ C. To the distillate dry magnesium metal and sodium was

added and it was refluxed for sometime followed by distillation.

Fractional distillate at 78˚ C and 740mm pressure was collected178.

Ethanol collected was kept in a tightly stoppered bottle owing to its

extremely hygroscopic properties.

Propan-1-ol:-

Propan-1-ol was treated with sodium metal and distilled. The

fraction distilled at 96.2˚ C and 760 mm was collected178.

Butan-1-ol:-

Butan-1-ol was kept over sodium metal for four hours and then

distilled over fresh sodium metal and fraction distilled178at 117.2˚ C.

Pentan-1-ol:-

Pentan-1-ol was kept over sodium metal for four hours and then

distilled over fresh sodium metal and fraction distilled178over fresh

sodium metal at 136.0˚ C.

26

Hexan-1-ol:-

Hexan-1-ol was kept over sodium metal for four hours and then

distilled over fresh sodium metal and fraction distilled178 over fresh

sodium metal at 156.5˚ C.

Reagents and their Purification

REAGENT SUPPLIER GRADE

Acetaldehyde Merck For synthesis

Acetone* Merck Extra Pure

Acetonitrile* Merck Pure

2-Aminophenol Fluka -

Benzaldehyde Merck For synthesis

Bromoethane Loba Chem. For synthesis

1-Bromopropane Fluka -

2,2΄-Bipyridyl Fluka -

Butane-1,4-dithiol Fluka -

Butane-1-thiol Fluka -

Butan-1-ol* Merck For synthesis

Butan-2-one Merck Extra Pure

2-tert-Butylphenol Merck For synthesis

2-tert-Buty-4-methoxylphenol Merck For synthesis

Chlorobenzene Merck Pure

1-Chlorobutane Fluka -

27

Cinnamaldehyde Fluka -

Decan-1-ol** Spectro Chem. AR

Dicyclopentadiene Fluka AR

Diethylether Fluka -

1-(dimethylamino)propan-2-ol Fluka -

Heptan-1-ol** Fluka -

Hexan-1-ol* Fluka -

Hexan-1,6-dithiol Fluka -

8-Hydroxyquinoline Merck Pure

Methanol* Merck Extra Pure

2-Nitrophenol Loba Chem. 99%

4-Nitrophenol Spectro Chem. AR

Nonan-1-ol** Fluka -

Octan-1-ol** Fluka -

Pentan-1-ol* Spectro Chem. AR

1,10-Phenanthroline Spectro Chem. AR

Phenol Merck For synthesis

Phosphorus pentoxide Fluka -

Potassium bromate Merck Pure

Potassium bromide Merck Pure

Propan-1-ol* Merck For synthesis

Salicylaldehyde Merck For synthesis

Salicylic acid Merck Pure

28

Silver nitrate Merck Pure

Tetrabutylammonium chloride* ACROS 95%

Thiophenol Spectro Chem. For synthesis

Bismuth metal Loba Chem. 95%

* The purification of these chemicals is discussed earlier.** These chemicals are purified by distillation and others are used as supplied.

29

Apparatus used

Electrolytic cell:-

Electrolysis was carried out in H-type pyrex glass cell. The cell

consists of two compartments; anode and cathode, which were separated

from each other by sintered glass disc of G-3 porosity. Anode

compartment is larger than cathode compartment. For preparing the

bismuth compounds electrochemically, bismuth electrode (2.0 X 10.0 x

0.2 cm3) was dipped in larger compartment and platinum gauge

(2.0 X 1.0 X 1.0 cm3) was dipped in smaller compartment. Both these

compartments were fitted with guard tubes. Bismuth electrode was

made anode by connecting it to positive terminal of the direct current

power supply and platinum gauge was made cathode by connecting it to

negative terminal of power supply (Toshniwal make). The potential

across the electrodes was so adjusted so that a current of 20 mA passed

through the cell. The solution was stirred effectively with the help of

magnetic stirrer (Figure - I).

Power Supply:-

Direct current was obtained from electrophoresis power supply of

‘Toshniwal’ make. Direct current power supply was fitted with a

voltmeter capable of indicating 0 – 100 V and an ammeter capable of

indicating 0 – 100 mA of current.

30

Figure – I

H – Type Cell for Electrochemical Reactions

31

Magnetic stirrer:-

The electrolytic solution was effectively stirred with the help of

magnetic stirrer of ‘Remi’ make. Magnetic bead sealed with Teflon was

used for stirring. The stirring increased the rate of reaction and also

removed the products deposited on the electrode surface.

Infrared Spectrophotometer:-

Infrared spectra of the products were recorded with Perkin Elmer

Spectrophotometer RXI using potassium bromide pellets in the region of

4000 - 450 cm-1 and polythene plates in the region of 450 – 250 cm-1.

Melting Point device:-

Melting points of the products of the electrochemical reactions

were also recorded by using electrical devices of ‘Perfit’ make. The

instrument is adjusted so that the temperature changed by five degree

per minute in order to measure the melting point accurately.

32

PART (B)

Electrochemical Synthesis and Isolation of Bismuth Compounds

For convenience of presentation the experimental work is further

divided into six sub-parts:

a) Electrochemical Reactions of Various Alcohols at Bismuth Anode.

b) Electrochemical Reactions of Various Phenols at Bismuth Anode.

c) Electrochemical Reactions of Various Thiols at Bismuth Anode.

d) Electrochemical Reactions of compounds with abstractable

hydrogen at Bismuth Anode.

e) Electrochemical Reactions of Various Aldehydes and Ketones at

Bismuth Anode.

f) Electrochemical synthesis of Organobismuth compounds.

33

a) Electrochemical Reactions of Various Alcohols at Bismuth Anode.

Methanol – Bi(+) system:-

The solution of 2.0 mL of methanol, 1.0 g of tetrabutylammonium

chloride in 250 ml of acetonitrile was taken in H – type cell and was

electrolysed at bismuth anode and platinum cathode by passing 20 mA

current with efficient stirring. After electrolysis of one hour, brown

coloured product started separating in the anode compartment. The

reaction mixture was electrolysed for ten hours and the product so

obtained was filtered, washed with acetonitrile and dry ether repeatedly

and then dried under vacuum.

Ethanol – Bi(+) system:-

2.0 mL of ethanol, 1.0 g of tetrabutylammonium chloride and 250

ml of acetonitrile was taken in the electrolytic cell. Bismuth electrode

was dipped in the anode compartment and platinum guage was dipped

in the cathode compartment. Both the electrodes were connected to the

source of direct current power supply. The potential across the

electrodes was so adjusted that a current of 20 mA passed through the

cell. The solution was stirred continuously. After electrolysis of one hour,

light brown coloured solid product started separating in the anode

compartment. The solution was electrolysed for twelve hours so that a

sufficient amount of product was obtained. The solution was filtered in

glass filtration unit of G-3 porosity and the product so obtained was

washed repeatedly with acetonitrile and dry ether and then dried under

vacuum.

34

Propan-1-ol – Bi(+) system:-

2.0 mL of propan-1-ol, 1.0 g of tetrabutylammonium chloride was

dissolved in 250 ml of acetonitrile. The solution was electrolysed at

bismuth anode and platinum cathode by passing 20 mA current through

the electrolytic cell. After electrolysis of one hour, light brown coloured

solid product separated in the anode compartment. Electrolysis was

carried out for twelve hours. The reaction mixture was filtered, washed

with acetonitrile and dry ether repeatedly and then dried under vacuum.

Butan-1-ol – Bi(+) system:-

2.0 mL of butan-1-ol, 1.0 g of tetrabutylammonium chloride was

dissolved in 250 ml of acetonitrile. The solution was taken in H-type cell,

which was then electrolysed at bismuth anode and platinum cathode by

passing a current of 20 mA. Creamy white coloured solid product started

separating in the anode compartment after electrolysis of one hour. The

reaction mixture was electrolysed for twelve hours to obtain enough

amount of the product, which was filtered, washed with acetonitrile and

dry ether repeatedly and then dried under vacuum.

Pentan-1-ol – Bi(+) system:-

The solution containing 2.0 mL of pentan-1-ol, 1.0 g of

tetrabutylammonium chloride and 250 ml of acetonitrile was taken in H-

type cell and the solution was electrolysed at bismuth anode and

platinum cathode by passing a current of 20 mA. After electrolysis of one

hour, light brown coloured solid product separated in the anode

compartment. The reaction mixture was electrolysed for twelve hours to

35

obtain enough amount of the product, which was filtered, washed with

acetonitrile and dry ether repeatedly and then dried under vacuum.

Hexan-1-ol – Bi(+) system:-

The solution containing 2.0 mL of pentan-1-ol, 1.0 g of

tetrabutylammonium chloride dissolved in 250 ml of acetonitrile was

taken in H-type cell and the solution was electrolysed at bismuth anode

and platinum cathode by passing a current of 20 mA. After electrolysis of

one hour, light brown coloured solid product started separating in the

anode compartment. The reaction mixture was electrolysed for twelve

hours and the product so obtained was filtered, washed with acetonitrile

and dry ether repeatedly and then dried under vacuum.

Heptan-1-ol – Bi(+) system:-

In H-type cell 2.0 mL of heptan-1-ol, 1.0 g of

tetrabutylammonium chloride and 250 ml of acetonitrile was taken and

the solution was electrolysed at bismuth anode and platinum cathode by

passing 20 mA current. After electrolysis of one hour, light brown

coloured solid product separated in the anode compartment. The

solution was electrolysed for twelve hours so that a sufficient amount of

the product was obtained. The electrtolysed solution was filtered,

washed with acetonitrile and dry ether repeatedly and then dried under

vacuum.

36

Octan-1-ol – Bi(+) system:-

In the electrolytic cell 2.0 mL of octan-1-ol, 1.0 g of



passing a current of 20 mA with efficient stirring. After electrolysis of one

hour, light brown coloured solid product started separating in the anode


sufficient amount of the product was obtained. The electrtolysed solution

was filtered, washed with acetonitrile and dry ether repeatedly and then

dried under vacuum.

Nonan-1-ol – Bi(+) system:-

2.0 mL of nonan-1-ol, 1.0 g of tetrabutylammonium chloride was

dissolved in 250 ml of acetonitrile and the solution was taken in H-type

cell which was electrolysed at bismuth anode and platinum cathode by

passing a current of 20 mA. After electrolysis of one hour, light brown

coloured solid product started separating in the anode compartment. In

order to obtain a sufficient amount of the product, the reaction mixture

was electrolysed for twelve hours and was filtered, washed with


Decan-1-ol – Bi(+) system:-

2.0 mL of decan-1-ol, 1.0 g of tetrabutylammonium chloride was

dissolved in 250 ml of acetonitrile and was taken in H-type cell and the

solution was electrolysed at bismuth anode and platinum cathode by

passing 20 mA current. After electrolysis of one hour, light brown

37

coloured solid product started separating in the anode compartment.

The reaction mixture was electrolysed for twelve hours and the product

so obtained and was filtered, washed with acetonitrile and dry ether

repeatedly and then dried under vacuum.

Dodecan-1-ol – Bi(+) system:-

Electrolysis of the solution of 2.0 mL of dodecan-1-ol, 1.0 g of

tetrabutylammonium chloride and 250 ml of acetonitrile was conducted

by passing 20 mA current. Light brown coloured solid product started

separating in the anode compartment after one hour of electrolysis. The

reaction mixture was electrolysed for twelve hours and the product was

filtered, washed with acetonitrile and dry ether repeatedly and then dried

under vacuum.

3-Methylhexan-3-ol – Bi(+) system:-

2.0 mL of 3-Methylhexan-3-ol, 1.0 g of tetrabutylammonium

chloride dissolved in 250 ml of acetonitrile was taken in H-type cell and


passing a current of 20 mA. Light brown coloured solid product started

separating in the anode compartment after one hour of electrolysis. The

solution was electrolysed for twelve hours. The product obtained was


under vacuum.

38

1-(dimethylamino)propan-2-ol – Bi(+) system:-

In the electrolytic cell 2.0 mL of 1-(dimethylamino)propan-2-ol,

1.0 g of tetrabutylammonium chloride and 250 ml of acetonitrile was

taken. The solution was electrolysed at bismuth anode and platinum

cathode by passing a current of 20 mA. After one hour of electrolysis,

light brown coloured solid product separated in the anode compartment.

The solution was electrolysed for twelve hours so that a sufficient

amount of the product was obtained. The electrtolysed solution was


under vacuum.

Coordination Compounds of Bismuth (III) Alkoxides

The electrochemical product of methanol - Bi(+) system (0.500 g)

was refluxed with 0.500 g of ligand (1,10-phenanthroline or 2,2΄-

bipyridyl) in various solvents like methanol, benzene and acetonitrile for

48 hours. The product was filtered, washed with same solvent and dry

ether and dried in vacuum.

The electrochemical product of ethanol - Bi(+) system (0.500 g)

was refluxed with 0.500 g of ligand (1,10-phenanthroline or 2,2΄-

bipyridyl) in various solvents like ethanol, benzene and acetonitrile. The

product was filtered after refluxing the mixture for 48 hours. The

product was filtered, washed with same solvent and dry ether and dried

under reduced pressure.

39

Methanol +1,10-phenanthroline – Bi(+) system:-

In H-type cell 2.0 mL of methanol, 1.0 g of 1,10-phenanthroline,

1.0 g of tetrabutylammonium chloride and 250 ml of acetonitrile solvent

was taken and the solution was electrolysed at bismuth anode and

platinum cathode by passing 20 mA current. After electrolysis of one

hour, yellow coloured product started separating in the anode

compartment. In order to obtain a sufficient amount of the product, the

reaction mixture was electrolysed for twelve hours and was filtered,


vacuum.

Ethanol +1,10-phenanthroline – Bi(+) system:-

The reaction mixture containing 2.0 mL of ethanol, 1.0 g of 1,10-

phenanthroline, 1.0 g of tetrabutylammonium chloride and 250 ml of

acetonitrile was taken in H-type cell and the solution was electrolysed at

bismuth anode and platinum cathode by passing 20 mA current. Yellow

coloured product started separating in the anode compartment after

electrolysis of one hour. The reaction mixture was electrolysed for twelve

hours. The product was filtered, washed repeatedly with acetonitrile and

dry ether and then dried under vacuum.

Propan-1-ol +1,10-phenanthroline – Bi(+) system:-

In H-type cell 2.0 mL of propan-1-ol, 1.0 g of 1,10-

phenanthroline, 1.0 g of tetrabutylammonium chloride was dissolved in

250 ml of acetonitrile and the solution was electrolysed at bismuth

anode and platinum cathode by passing 20 mA current. Dirty white

40



hours and was filtered, washed with acetonitrile and dry ether repeatedly


Butan-1-ol +1,10-phenanthroline – Bi(+) system:-

Electrolysis of solution of 2.0 mL of butan-1-ol, 1.0 g of 1,10-

phenanthroline, 1.0 g of tetrabutylammonium chloride in 250 ml of

acetonitrile was carried out in H-type cell and the solution was


current. After electrolysis of one hour, dark brown coloured product

started separating in the anode compartment. The reaction mixture was

electrolysed for twelve hours and the product so obtained was filtered,


vacuum.

Pentan-1-ol +1,10-phenanthroline – Bi(+) system:-

The solution of 2.0 mL of pentan-1-ol, 1.0 g of 1,10-



bismuth anode and platinum cathode by passing 20 mA current. Dark

brown coloured product started separating in the anode compartment

after electrolysis of one hour. The solution was electrolysed for twelve

hours and the product was filtered, washed repeatedly with acetonitrile

and dry ether and then dried under vacuum.

41

Hexan-1-ol +1,10-phenanthroline – Bi(+) system:-

In H-type cell 2.0 mL of hexan-1-ol, 1.0 g of 1,10-phenanthroline,

1.0 g of tetrabutylammonium chloride was dissolved in 250 ml of

acetonitrile and the solution was electrolysed at bismuth anode and


hour, dark brown coloured product started separating in the anode

compartment. The reaction mixture was electrolysed for twelve hours

and was filtered, washed with acetonitrile and dry ether repeatedly and

then dried under vacuum.

Heptan-1-ol +1,10-phenanthroline – Bi(+) system:-

In H-type cell 2.0 mL of heptan-1-ol, 1.0 g of 1,10-


acetonitrile solvent was taken and the solution was electrolysed at

bismuth anode and platinum cathode by passing 20 mA current. Light


after electrolysis of one hour. In order to obtain a sufficient amount of

the product, the reaction mixture was electrolysed for twelve hours and


dried under vacuum.

Octan-1-ol +1,10-phenanthroline – Bi(+) system:-

Electrolysis of solution of 2.0 mL of octan-1-ol, 1.0 g of 1,10-




42

current. After electrolysis of one hour, light brown coloured product




vacuum.

Nonan-1-ol +1,10-phenanthroline – Bi(+) system:-

The solution of 2.0 mL of nonan-1-ol, 1.0 g of 1,10-








Decan-1-ol +1,10-phenanthroline – Bi(+) system:-

2.0 mL of decan-1-ol, 1.0 g of 1,10-phenanthroline, 1.0 g of



platinum cathode by passing 20 mA current. Light brown coloured

product started separating in the anode compartment after electrolysis of

one hour. The reaction mixture was electrolysed for twelve hours. The

product was filtered, washed repeatedly with acetonitrile and dry ether


43

Dodecan-1-ol +1,10-phenanthroline – Bi(+) system:-

Electrolysis of the solution of 2.0 mL of dodecan-1-ol, 1.0 g of

1,10-phenanthroline, 1.0 g of tetrabutylammonium chloride and 250

ml of acetonitrile was conducted by passing 20 mA current. Dark brown

coloured solid product separated in the anode compartment after one

hour of electrolysis. The reaction mixture was electrolysed for twelve

hours and the product was filtered, washed with acetonitrile and dry

ether repeatedly and then dried under vacuum.

3-Methylhexan-3-ol +1,10-phenanthroline – Bi(+) system:-

2.0 mL of 3-Methylhexan-3-ol, 1.0 g of 1,10-phenanthroline, 1.0

g of tetrabutylammonium chloride dissolved in 250 ml of acetonitrile was


and platinum cathode by passing a current of 20 mA. Light brown


hour of electrolysis. The solution was electrolysed for twelve hours. The

product obtained was filtered, washed with acetonitrile and dry ether


1-(dimethylamino)propan-2-ol +1,10-phenanthroline – Bi(+) system:-

In the electrolytic cell 2.0 mL of 1-(dimethylamino)propan-2-ol,

1.0 g of 1,10-phenanthroline, 1.0 g of tetrabutylammonium chloride and

250 ml of acetonitrile was taken. The solution was electrolysed at

bismuth anode and platinum cathode by passing a current of 20 mA.

After one hour of electrolysis, light brown coloured solid product

separated in the anode compartment. The solution was electrolysed for

44

twelve hours so that a sufficient amount of the product was obtained.

The electrtolysed solution was filtered, washed with acetonitrile and dry


Methanol + 2,2′-bipyridyl– Bi(+) system:-

The reaction mixture containing 2.0 mL of methanol, 1.0 g of

2,2΄-bipyridyl, 1.0 g of tetrabutylammonium chloride and 250 ml of


bismuth anode and platinum cathode by passing 20 mA current. Yellow



hours. The product was filtered, washed repeatedly with acetonitrile and

dry ether and then dried under vacuum.

Ethanol + 2,2′-bipyridyl– Bi(+) system:-

In H-type cell 2.0 mL of ethanol, 1.0 g of 2,2′-bipyridyl, 1.0 g of

tetrabutylammonium chloride and 250 ml of acetonitrile solvent was

taken and the solution was electrolysed at bismuth anode and platinum

cathode by passing 20 mA current. After electrolysis of one hour, brown

coloured product started separating in the anode compartment. In order

to obtain a sufficient amount of the product, the reaction mixture was

electrolysed for twelve hours and was filtered, washed with acetonitrile


Propan-1-ol + 2,2′-bipyridyl– Bi(+) system:-

Electrolysis of solution of 2.0 mL of propan-1-ol, 1.0 g of 2,2΄-

bipyridyl, 1.0 g of tetrabutylammonium chloride in 250 ml of acetonitrile

45

was carried out in H-type cell and the solution was electrolysed at

bismuth anode and platinum cathode by passing 20 mA current. After

electrolysis of one hour, dirty white coloured product started separating

in the anode compartment. The reaction mixture was electrolysed for

twelve hours and the product so obtained was filtered, washed

repeatedly with acetonitrile and dry ether and then dried under vacuum.

Butan-1-ol + 2,2′-bipyridyl– Bi(+) system:-

In H-type cell 2.0 mL of butan-1-ol, 1.0 g of 2,2΄-bipyridyl, 1.0 g

of tetrabutylammonium chloride was dissolved in 250 ml of acetonitrile

and the solution was electrolysed at bismuth anode and platinum

cathode by passing 20 mA current. Dark brown coloured product started

separating in the anode compartment after electrolysis of one hour. The

reaction mixture was electrolysed for twelve hours and was filtered,


vacuum.

Pentan-1-ol + 2,2′-bipyridyl– Bi(+) system:-

In H-type cell 2.0 mL of pentan-1-ol, 1.0 g of 2,2΄-bipyridyl, 1.0 g


and the solution was electrolysed at bismuth anode and platinum

cathode by passing 20 mA current. After electrolysis of one hour, dark

brown coloured product started separating in the anode compartment.

The reaction mixture was electrolysed for twelve hours and was filtered,


vacuum.

46

Hexan-1-ol + 2,2′-bipyridyl– Bi(+) system:-

The solution of 2.0 mL of hexan-1-ol, 1.0 g of 2,2΄-bipyridyl, 1.0 g

of tetrabutylammonium chloride and 250 ml of acetonitrile was taken in

H-type cell and the solution was electrolysed at bismuth anode and

platinum cathode by passing 20 mA current. Dark brown coloured


one hour. The solution was electrolysed for twelve hours and the product

was filtered, washed repeatedly with acetonitrile and dry ether and then

dried under vacuum.

Heptan-1-ol + 2,2′-bipyridyl– Bi(+) system:-

Electrolysis of solution of 2.0 mL of heptan-1-ol, 1.0 g of 2,2΄-

bipyridyl, 1.0 g of tetrabutylammonium chloride in 250 ml of acetonitrile

was carried out in H-type cell and the solution was electrolysed at


electrolysis of one hour, light brown coloured product started separating

in the anode compartment. The reaction mixture was electrolysed for

twelve hours and the product so obtained was filtered, washed


Octan-1-ol + 2,2′-bipyridyl– Bi(+) system:-

In H-type cell 2.0 mL of octan-1-ol, 1.0 g of 2,2΄-bipyridyl, 1.0 g

of tetrabutylammonium chloride and 250 ml of acetonitrile solvent was


cathode by passing 20 mA current. Light brown coloured product started

separating in the anode compartment after electrolysis of one hour. In

47

order to obtain a sufficient amount of the product, the reaction mixture

was electrolysed for twelve hours and was filtered, washed with


Nonan-1-ol + 2,2′-bipyridyl– Bi(+) system:-

2.0 mL of nonan-1-ol, 1.0 g of 2,2΄-bipyridyl, 1.0 g of



platinum cathode by passing 20 mA current. Dark brown coloured





Decan-1-ol + 2,2′-bipyridyl– Bi(+) system:-

The solution of 2.0 mL of decan-1-ol, 1.0 g of 2,2΄-bipyridyl, 1.0 g

of tetrabutylammonium chloride and 250 ml of acetonitrile was taken in

H-type cell and the solution was electrolysed at bismuth anode and

platinum cathode by passing 20 mA current. Light brown coloured


one hour. The solution was electrolysed for twelve hours and the product

was filtered, washed repeatedly with acetonitrile and dry ether and then

dried under vacuum.

Dodecan-1-ol + 2,2′-bipyridyl– Bi(+) system:-

2.0 mL of dodecan-1-ol, 1.0 g of 2,2΄-bipyridyl, 1.0 g of


48


and platinum cathode by passing a current of 20 mA. Dark brown

coloured solid product started separating in the anode compartment

after one hour of electrolysis. The solution was electrolysed for twelve

hours. The product obtained was filtered, washed with acetonitrile and


3-Methylhexan-3-ol + 2,2′-bipyridyl– Bi(+) system:-

Electrolysis of the solution of 2.0 mL of 3-Methylhexan-3-ol of,

1.0 g of 2,2΄-bipyridyl, 1.0 g of tetrabutylammonium chloride and 250

ml of acetonitrile was conducted by passing 20 mA current. Light brown

coloured solid product started separating in the anode compartment

after one hour of electrolysis. The reaction mixture was electrolysed for

twelve hours and the product was filtered, washed with acetonitrile and


1-(dimethylamino)propan-2-ol + 2,2′-bipyridyl– Bi(+) system:-

In the electrolytic cell 2.0 mL of 1-(dimethylamino)propan-2-ol, 1.0

g of 2,2΄-bipyridyl, 1.0 g of tetrabutylammonium chloride and 250 ml of

acetonitrile was taken. The solution was electrolysed at bismuth anode

and platinum cathode by passing a current of 20 mA. After one hour of

electrolysis, light brown coloured solid product separated in the anode


sufficient amount of the product was obtained. The electrolysed solution


dried under vacuum.

49

b) Electrochemical Reactions of Various Phenols at Bismuth Anode

Phenol - Bi(+) system:-

2.0 g of phenol, 1.0 g of tetrabutylammonium chloride and 250

ml of acetonitrile was taken in the electrolytic cell. Bismuth electrode

was dipped in the anode compartment and platinum gauge was dipped

in cathode compartment. Both the electrodes were connected to the

source of direct current power supply. The potential across the


cell. The solution was stirred continuously. Solid product started

separating in the anode compartment after one hour of electrolysis. After

the electrolysis of twelve hours, cream coloured solid product was

separated in the anode compartment. The solution was filtered in glass

filtration unit of G-3 porosity. The product obtained was washed

repeatedly with acetonitrile and dry ether than dried under vacuum.

1-Naphthol - Bi(+) system:-

Electrolysis of 2.0 g of 1-Naphthol, 1.0 g of tetrabutylammonium

chloride and 250 ml of acetonitrile was carried out in H-type cell using

bismuth anode and platinum cathode by passing 20 mA current. As the

electrolysis proceeded, dark brown solid product started separating in

the anode compartment. The reaction mixture was electrolysed for twelve

hours. The reaction mixture was then filtered. The product was washed

with acetonitrile and dry ether repeatedly and then dried under reduced

pressure.

50

2-Naphthol - Bi(+) system:-

The electrolysis of solution containing 2.0 g of 2-Naphthol, 1.0 g

of tetrabutylammonium chloride in 250 ml of acetonitrile was conducted

at bismuth anode and platinum cathode in H-type cell by passing 20 mA

current. As the electrolysis proceeded dark brown solid product

separated in the anode compartment. The reaction mixture was filtered

after electrolysis of twelve hours. The product was washed repeatedly

with acetonitrile and dry ether than dried under vacuum.

4-Aminophenol - Bi(+) system:-

The electrolysis of solution containing 2.0 g of 4-aminophenol,

1.0 g of tetrabutylammonium chloride in 250 ml of acetonitrile was

conducted at bismuth anode and platinum cathode in H-type cell by

passing 20 mA current. As the electrolysis proceded brown colourd solid

product separated in the anode compartment. The reaction mixture was

filtered after electrolysis of twelve hours. The product was washed


2-Nitrophenol - Bi(+) system:-

Electrolysis of 2.0 mL of 2-Nitrophenol, 1.0 g of

tetrabutylammonium chloride and 250 ml of acetonitrile was carried out

in H-type cell using bismuth anode and platinum cathode by passing 20

mA current. As the electrolysis proceeded, brown solid product started

separating in the anode compartment. The reaction mixture was

electrolysed for twelve hours. The reaction mixture was then filtered. The

51

product was washed with acetonitrile and dry ether repeatedly and then

dried under reduced pressure.

4-Nitrophenol - Bi(+) system:-

The reaction mixture containing 2.0 mL of 4-Nitrophenol, 1.0 g of



platinum cathode by passing 20 mA current. Brown coloured product

started separating in the anode compartment after electrolysis of one

hour. The reaction mixture was electrolysed for twelve hours. The



p-Cresol – Bi(+) system:-

The reaction mixture containing 2.0 mL of p-cresol, 1.0 g of



platinum cathode by passing 20 mA current. Dirty white coloured





Resorcinol – Bi(+) system:-

In the electrolytic cell 2.0 mL of resorcinol, 1.0 g of

tetrabutylammonium chloride and 250 ml of acetonitrile was taken. The


52

passing a current of 20 mA. After one hour of electrolysis, brown





vacuum.

2-tertbutylphenol – Bi(+) system:-

2.0 g of 2-tertbutylphenol, 1.0 g of tetrabutylammonium chloride

and 250 ml of acetonitrile was taken in H-type cell and the solution was


current. Dirty white coloured product started separating in the anode

compartment after electrolysis of one hour. The reaction mixture was

electrolysed for twelve hours. The product was filtered, washed


2-tertbutyl-4-methoxyphenol – Bi(+) system:-

In the electrolytic cell 2.0 g of 2-tertbutyl-4-methoxyphenol, 1.0 g

of tetrabutylammonium chloride and 250 ml of acetonitrile was taken.

The solution was electrolysed at bismuth anode and platinum cathode

by passing a current of 20 mA. After one hour of electrolysis, dirty white





vacuum.

53

2-Hydroxybenzoic acid- Bi(+) system:-

Electrolysis of 2.0 mL of 2-hydroxybenzoic acid, 1.0 g of


in H-type cell using bismuth anode and platinum cathode by passing

20 mA current. As the electrolysis proceeded, brown coloured solid

product started separating in the anode compartment. The reaction

mixture was electrolysed for twelve hours. The reaction mixture was

then filtered. The product was washed with acetonitrile and dry ether

repeatedly and then dried under reduced pressure.

Coordination Compounds of Bi (III) Phenoxides

The product of phenol- Bi(+) system (0.500 g) was refluxed with

0.500 g of the ligand in various solvents like methanol, ethanol, benzene

and acetonitrile. The product was filtered after refluxing the mixture for

48 hours. It was then washed with the same solvent and dry ether and


Phenol +1,10-phenanthroline - Bi(+) system:-

Electrolysis of 2.0 g of phenol, 1.0 g of 1,10-phenanthroline, 1.0 g

of tetrabutylammonium chloride and 250 ml of acetonitrile was carried

out in H-type cell using bismuth anode and platinum cathode by passing

20 mA current. As the electrolysis proceeded, brown solid product





54

1-Naphthol +1,10-phenanthroline - Bi(+) system:-

The electrolysis of solution containing 2.0 g of 1-Naphthol, 1.0 g

of 1,10-phenanthroline,1.0 g of tetrabutylammonium chloride in 250 ml

of acetonitrile was conducted at bismuth anode and platinum cathode in

H-type cell by passing 20 mA current. As the electrolysis proceeded dark

brown solid product separated in the anode compartment. The reaction

mixture was filtered after electrolysis of twelve hours. The product was

washed repeatedly with acetonitrile and dry ether than dried under

vacuum.

2-Naphthol +1,10-phenanthroline - Bi(+) system:-

In the electrolytic cell 2.0 g of 2-Naphthol, 1.0 g of 1,10-




electrolysis, brown coloured solid product started separating in the

anode compartment. The solution was electrolysed for twelve hours so

that a sufficient amount of the product was obtained. The electrtolysed

solution was filtered, washed with acetonitrile and dry ether repeatedly


4-Aminophenol +1,10-phenanthroline - Bi(+) system:-

Electrolysis of 2.0 g of 4-aminophenol, 1.0 g of 1,10-

phenanthroline,1.0 g of tetrabutylammonium chloride and 250 ml of

acetonitrile was carried out in H-type cell using bismuth anode and

platinum cathode by passing 20 mA current. As the electrolysis

55

proceeded, crem solid product started separating in the anode

compartment. The reaction mixture was electrolysed for twelve hours.

The reaction mixture was then filtered. The product was washed with

acetonitrile and dry ether repeatedly and then dried under reduced

pressure.

2-Nitrophenol +1,10-phenanthroline - Bi(+) system:-

In the electrolytic cell 2.0 mL of 2-Nitrophenol, 1.0 g of 1,10-




electrolysis, brown coloured solid product separated in the anode




dried under vacuum.

4-Nitrophenol +1,10-phenanthroline - Bi(+) system:-

The reaction mixture containing 2.0 mL of 4-Nitrophenol, 1.0 g of

1,10-phenanthroline,1.0 g of tetrabutylammonium chloride and 250 ml

of acetonitrile was taken in H-type cell and the solution was electrolysed

at bismuth anode and platinum cathode by passing 20 mA current.

Brown coloured product started separating in the anode compartment

after electrolysis of one hour. The reaction mixture was electrolysed for

twelve hours. The product was filtered, washed repeatedly with

acetonitrile and dry ether and then dried under vacuum.

56

p-Cresol +1,10-phenanthroline – Bi(+) system:-

2.0 mL of p-cresol, 1.0 g of 1,10-phenanthroline,1.0 g of



platinum cathode by passing 20 mA current. Cream coloured product

started separating in the anode compartment after electrolysis of one

hour. The reaction mixture was electrolysed for twelve hours. The



Resorcinol +1,10-phenanthroline – Bi(+) system:-

The electrolysis of solution containing 2.0 g of resorcinol, 1.0 g of

1,10-phenanthroline,1.0 g of tetrabutylammonium chloride in 250 ml of

acetonitrile was conducted at bismuth anode and platinum cathode in

H-type cell by passing 20 mA current. As the electrolysis proceeded

brown solid product separated in the anode compartment. The reaction

mixture was filtered after electrolysis of twelve hours. The product was

washed repeatedly with acetonitrile and dry ether than dried under

vacuum.

2-tertbutylphenol +1,10-phenanthroline – Bi(+) system:-

The reaction mixture containing 2.0 g of 2-tertbutylphenol, 1.0 g

of 1,10-phenanthroline,1.0 g of tetrabutylammonium chloride and 250

ml of acetonitrile was taken in H-type cell and the solution was


current. Dark brown coloured product started separating in the anode

57




2-tertbutyl-4-methoxyphenol +1,10-phenanthroline – Bi(+) system:-

Electrolysis of 2.0 g of 2-tertbutyl-4-methoxyphenol, 1.0 g of


of acetonitrile was carried out in H-type cell using bismuth anode and


proceeded, dark brown product started separating in the anode




pressure.

2-Hydroxybenzoic acid +1,10-phenanthroline - Bi(+) system:-

2.0 mL of 2-hydroxybenzoic acid, 1.0 g of 1,10-phenanthroline,


taken in the electrolytic cell. Bismuth electrode was dipped in the anode

compartment and platinum gauge was dipped in cathode compartment.

Both the electrodes were connected to the source of direct current power

supply. The potential across the electrodes was so adjusted so that a

current of 20 mA passed through the cell. The solution was stirred

continuously. Solid product separated in the anode compartment after

one hour of electrolysis. After the electrolysis of twelve hours, brown

colourd solid product was separated in the anode compartment. The

58

solution was filtered in glass filtration unit of G-3 porosity. The product

obtained was washed repeatedly with acetonitrile and dry ether than

dried under vacuum.

Phenol + 2,2′-bipyridyl- Bi(+) system:-

The solution of 2.0 g of Phenol, 1.0 g of 2,2΄-bipyridyl, 1.0 g of

tetrabutylammonium chloride in 250 ml of acetonitrile was taken in H –

type cell and was electrolysed at bismuth anode and platinum cathode

by passing 20 mA current with efficient stirring. After electrolysis of one

hour, brown coloured product started separating in the anode

compartment. The reaction mixture was electrolysed for ten hours and

the product so obtained was filtered, washed with acetonitrile and dry


1-Naphthol + 2,2′-bipyridyl- Bi(+) system:-

2.0 g of 1-Naphthol, 1.0 g of 2,2΄-bipyridyl, 1.0 g of

tetrabutylammonium chloride was dissolved in 250 ml of acetonitrile.

The solution was taken in H-type cell, which was then electrolysed at


Brown coloured solid product was separated in the anode compartment


twelve hours to obtain enough amount of the product, which was


under vacuum.

59

2-Naphthol + 2,2′-bipyridyl- Bi(+) system:-

The solution containing 2.0 g of 2-Naphthol, 1.0 g of 2,2΄-

bipyridyl, 1.0 g of tetrabutylammonium chloride and 250 ml of



After electrolysis of one hour, dark brown coloured solid product

separated in the anode compartment. The reaction mixture was

electrolysed for twelve hours to obtain enough amount of the product,

which was filtered, washed with acetonitrile and dry ether repeatedly


4-Aminophenol + 2,2′-bipyridyl- Bi(+) system:-

2.0 g of 4-Aminophenol, 1.0 g of 2,2΄-bipyridyl, 1.0 g of



by passing 20 mA current through the electrolytic cell. After electrolysis

of one hour, cream coloured solid product separated in the anode

compartment. Electrolysis was carried out for twelve hours. The reaction

mixture was filtered, washed with acetonitrile and dry ether repeatedly


2-Nitrophenol + 2,2′-bipyridyl- Bi(+) system:-

2.0 mL of 2-Nitrophenol, 1.0 g of 2,2΄-bipyridyl, 1.0 g of

tetrabutylammonium chloride was dissolved in 250 ml of acetonitrile

and was taken in H-type cell and the solution was electrolysed at


60

electrolysis of one hour, dark brown coloured solid product separated in


hours and the product so obtained and was filtered, washed with


4-Nitrophenol + 2,2′-bipyridyl- Bi(+) system:-

Electrolysis of the solution of 2.0 mL of 4-Nitrophenol, 1.0 g of


acetonitrile was conducted by passing 20 mA current. Cream coloured

solid product separated in the anode compartment after one hour of

electrolysis. The reaction mixture was electrolysed for twelve hours and

the product was filtered, washed with acetonitrile and dry ether


p-Cresol + 2,2′-bipyridyl– Bi(+) system:-

In H-type cell 2.0 mL of p-Cresol, 1.0 g of 2,2΄-bipyridyl, 1.0 g of



passing 20 mA current. After electrolysis of one hour, brown coloured

solid product separated in the anode compartment. The solution was

electrolysed for twelve hours so that a sufficient amount of the product

was obtained. The electrtolysed solution was filtered, washed with


Resorcinol + 2,2′-bipyridyl– Bi(+) system:-

The solution containing 2.0 mL of resorcinol, 1.0 g of 2,2΄-

bipyridyl, 1.0 g of tetrabutylammonium chloride dissolved in 250 ml of

61



After electrolysis of one hour, brown coloured solid product started




vacuum.

2-tertbutylphenol + 2,2′-bipyridyl– Bi(+) system:-

In the electrolytic cell 2.0 g of 2-tertbutylphenol, 1.0 g of 2,2΄-


acetonitrile was taken and the solution was electrolysed at bismuth

anode and platinum cathode by passing a current of 20 mA with efficient

stirring. After electrolysis of one hour, brown coloured solid product





2-tertbutyl-4-methoxyphenol + 2,2′-bipyridyl– Bi(+) system:-

2.0 g of 2-tertbutyl-4-methoxyphenol, 1.0 g of 2,2΄-bipyridyl,1.0 g


and the solution was taken in H-type cell which was electrolysed at



separated in the anode compartment. In order to obtain a sufficient

62

amount of the product, the reaction mixture was electrolysed for twelve



2-Hydroxybenzoic acid + 2,2′-bipyridyl- Bi(+) system:-

2.0 mL of 2-hydroxybenzoic acid, 1.0 g of 2,2′-bipyridyl, 1.0 g of

tetrabutylammonium chloride and 250 ml of acetonitrile was taken in

the electrolytic cell. Bismuth electrode was dipped in the anode

compartment and platinum gauge was dipped in the cathode

compartment. Both the electrodes were connected to the source of direct

current power supply. The potential across the electrodes was so

adjusted that a current of 20 mA passed through the cell. The solution

was stirred continuously. After electrolysis of one hour, dark brown



amount of product was obtained. The solution was filtered in glass

filtration unit of G-3 porosity and the product so obtained was washed


63

c) Electrochemical Reactions of Various Thiols and Dithiols at

Bismuth Anode.

Ethanethiol - Bi(+) system:-

2.0 mL of ethanethiol, 1.0 g of tetrabutylammonium chloride and

250 ml of acetonitrile was taken in the electrolytic cell. Bismuth

electrode was dipped in the anode compartment and platinum gauge was

dipped in the cathode compartment. Both the electrodes were connected

to the source of direct current power supply. The potential across the



pink coloured solid product started separating in the anode





vacuum.

2-Propane thiol – Bi(+) system:-

2.0 mL of 2-Propane thiol, 1.0 g of tetrabutylammonium chloride

was dissolved in 250 ml of acetonitrile. The solution was electrolysed at

bismuth anode and platinum cathode by passing 20 mA current through

the electrolytic cell. After electrolysis of one hour, yellow coloured solid

product separated in the anode compartment. Electrolysis was carried

out for twelve hours. The reaction mixture was filtered, washed with


64

2-Methylpropane-2-thiol – Bi(+) system:-

The solution containing 2.0 mL of 2-Methylpropane-2-thiol, 1.0 g

of tetrabutylammonium chloride dissolved in 250 ml of acetonitrile was



one hour, light yellow coloured solid product started separating in the




Butanethiol – Bi(+) system:-

2.0 mL of butanethiol, 1.0 g of tetrabutylammonium chloride was

dissolved in 250 ml of acetonitrile. The solution was taken in H-type cell,

which was then electrolysed at bismuth anode and platinum cathode by

passing a current of 20 mA. Orange coloured solid product was

separated in the anode compartment after electrolysis of one hour. The

reaction mixture was electrolysed for twelve hours to obtain enough



1-Pentane thiol – Bi(+) system:-

The solution containing 2.0 mL of 1-pentane thiol, 1.0 g of




hour, pink coloured solid product separated in the anode compartment.

65

The reaction mixture was electrolysed for twelve hours to obtain enough



Ethane-1,2-dithiol– Bi(+) system:-

In H-type cell 2.0 mL of ethane-1,2-dithiol, 1.0 g of



passing 20 mA current. After electrolysis of one hour, purple coloured

solid product separated in the anode compartment. The solution was

electrolysed for twelve hours so that a sufficient amount of the product

was obtained. The electrtolysed solution was filtered, washed with


Butane-1,4-dithiol – Bi(+) system:-

In the electrolytic cell 2.0 mL of butane-1,4-dithiol, 1.0 g of




hour, purple coloured solid product separated in the anode




dried under vacuum.

66

Coordination Compounds of Bi (III) Thiols/Dithiols

The product of thiols/dithiols - Bi(+) system (0.500 g) was refluxed

with 0.500 g of the ligand in various solvents like methanol, ethanol,

benzene and acetonitrile. The product was filtered after refluxing the

mixture for 48 hours. It was then washed with the same solvent and dry

ether and dried under reduced pressure.

Ethanethiol +1,10-phenanthroline - Bi(+) system:-

2.0 mL of ethanethiol, 1.0 g of 1,10-phenanthroline, 1.0 g of




After electrolysis of one hour, yellow coloured solid product separated in

the anode compartment. In order to obtain a sufficient amount of the

product, the reaction mixture was electrolysed for twelve hours and was


under vacuum.

2-Propan thiol +1,10-phenanthroline - Bi(+) system:-

2.0 mL of 2-propanthiol, 1.0 g of 1,10-phenanthroline, 1.0 g of




electrolysis of one hour, pink coloured solid product separated in the


67



2-Methylpropane-2-thiol +1,10-phenanthroline – Bi(+) system:-

In the electrolytic cell 2.0 mL of 2-Methylpropane-2-thiol, 1.0 g of


of acetonitrile was taken. The solution was electrolysed at bismuth

anode and platinum cathode by passing a current of 20 mA. After one

hour of electrolysis, yellow coloured solid product separated in the anode




dried under vacuum.

Butan-1-thiol +1,10-phenanthroline – Bi(+) system:-

Electrolysis of the solution of 2.0 mL of butan-1-thiol, 1.0 g of


of acetonitrile was conducted by passing 20 mA current. Pink coloured


electrolysis. The reaction mixture was electrolysed for twelve hours and

the product was filtered, washed with acetonitrile and dry ether


1-Pentanthiol +1,10-phenanthroline – Bi(+) system:-

2.0 mL of 1-pentanthiol, 1.0 g of 1,10-phenanthroline,1.0 g of



68

and platinum cathode by passing a current of 20 mA. Orange coloured


electrolysis. The solution was electrolysed for twelve hours. The product

obtained was filtered, washed with acetonitrile and dry ether repeatedly


Ethane-1,2-dithiol +1,10-phenanthroline - Bi(+) system:-

2.0 mL of ethane-1,2-dithiol, 1.0 g of 1,10-phenanthroline, 1.0 g




electrolysis of one hour, purple coloured solid product separated in the




Butane-1,4-dithiol +1,10-phenanthroline – Bi(+) system:-

Electrolysis of the solution of 2.0 mL of butane-1,4-dithiol, 1.0 g

of 1,10-phenanthroline,1.0 g of tetrabutylammonium chloride and 250

ml of acetonitrile was conducted by passing 20 mA current. purple





69

Ethanethiol + 2,2′-bipyridyl- Bi(+) system:-

The solution of 2.0 mL of ethanethiol, 1.0 g of 2,2΄-bipyridyl, 1.0

g of tetrabutylammonium chloride in 250 ml of acetonitrile was taken

in H – type cell and was electrolysed at bismuth anode and platinum

cathode by passing 20 mA current with efficient stirring. After

electrolysis of one hour, dirty yellow coloured product started separating

in the anode compartment. The reaction mixture was electrolysed for ten



2-Propanethiol + 2,2′-bipyridyl- Bi(+) system:-

2.0 mL of 2-propanethiol, 1.0 g of 2,2′-bipyridyl, 1.0 g of



compartment and platinum guage was dipped in the cathode




was stirred continuously. After electrolysis of one hour, yellow coloured

solid product started separating in the anode compartment. The solution

was electrolysed for twelve hours so that a sufficient amount of product

was obtained. The solution was filtered in glass filtration unit of G-3

porosity and the product so obtained was washed repeatedly with

acetonitrile and dry ether and then dried under vacuum.

70

2-Methylpropane-2-thiol + 2,2′-bipyridyl- Bi(+) system:-

The solution containing 2.0 mL of 2-Methylpropane-2-thiol, 1.0 g

of 2,2΄-bipyridyl, 1.0 g of tetrabutylammonium chloride and 250 ml of



After electrolysis of one hour, yellow coloured solid product separated in


hours to obtain enough amount of the product, which was filtered,


vacuum.

Butanethiol + 2,2′-bipyridyl- Bi(+) system:-

2.0 mL of butanethiol, 1.0 g of 2,2΄-bipyridyl, 1.0 g of




of one hour, orange coloured solid product separated in the anode




1-Pentanethiol + 2,2′-bipyridyl- Bi(+) system:-

2.0 mL of 1-pentanethiol, 1.0 g of 2,2΄-bipyridyl, 1.0 g of




71

Orange coloured solid product was separated in the anode compartment


twelve hours to obtain enough amount of the product, which was


under vacuum.

Ethane-1,2-dithiol + 2,2′-bipyridyl– Bi(+) system:-

The solution containing 2.0 mL of ethane-1,2-dithiol, 1.0 g of

2,2΄-bipyridyl, 1.0 g of tetrabutylammonium chloride dissolved in 250


electrolysed at bismuth anode and platinum cathode by passing a

current of 20 mA. After electrolysis of one hour, purple coloured solid

product started separating in the anode compartment. The reaction

mixture was electrolysed for twelve hours and the product so obtained


and then dried under vacuum

Butane-1,4-dithiol + 2,2′-bipyridyl– Bi(+) system:-

In H-type cell 2.0 mL of butane-1,2-dithiol, 1.0 g of 2,2΄-



anode and platinum cathode by passing 20 mA current. After

electrolysis of one hour, light purple coloured solid product separated in

the anode compartment. The solution was electrolysed for twelve hours

so that a sufficient amount of the product was obtained. The

72

electrtolysed solution was filtered, washed with acetonitrile and dry ether


73

d) Electrochemical Reactions of Compounds with Abstractable Hydrogen at Bismuth Anode

Acetylacetone - Bi(+) system:-

2.0 mL of acetylacetone, 1.0 g of tetrabutylammonium chloride

and 250 ml of acetonitrile was taken in the electrolytic cell. Bismuth


dipped in the cathode compartment. Both the electrodes were connected

to the source of direct current power supply. The potential across the



white coloured solid product started separating in the anode





vacuum.

2- Cyanoacetamide – Bi(+) system:-

2.0 mL of 2-cyanoacetamide, 1.0 g of tetrabutylammonium

chloride was dissolved in 250 ml of acetonitrile. The solution was


current through the electrolytic cell. After electrolysis of one hour, light

brown coloured solid product separated in the anode compartment.

Electrolysis was carried out for twelve hours. The reaction mixture was


under vacuum.

74

Ethylcyanoacetate – Bi(+) system:-

2.0 mL of ethylcyanoacetate and1.0 g of tetrabutylammonium

chloride was dissolved in 250 ml of acetonitrile. The solution was taken

in H-type cell, which was then electrolysed at bismuth anode and

platinum cathode by passing a current of 20 mA. Light brown coloured

solid product was separated in the anode compartment after electrolysis

of one hour. The reaction mixture was electrolysed for twelve hours to



Ethylacetoacetate – Bi(+) system:-

The solution containing 2.0 mL of ethylacetoacetate, 1.0 g of




hour, white coloured solid product separated in the anode compartment.

The reaction mixture was electrolysed for twelve hours to obtain enough



Diethylmalonate – Bi(+) system:-

The solution containing 2.0 mL of diethylmalonate and 1.0 g of




one hour, white coloured solid product started separating in the anode

75


and the product so obtained was filtered, washed with acetonitrile and


Acetylacetone +1,10-phenanthroline – Bi(+) system:-

The reaction mixture containing 2.0 mL of acetylacetone, 1.0 g of

1,10-phenanthroline, 1.0 g of tetrabutylammonium chloride and 250 ml

of acetonitrile was taken in H-type cell and the solution was electrolysed

at bismuth anode and platinum cathode by passing 20 mA current.

Light brown coloured product started separating in the anode




2-Cyanoacetamide +1,10-phenanthroline – Bi(+) system:-

In H-type cell 2.0 mL of 2-cyanoacetamide, 1.0 g of 1,10-



anode and platinum cathode by passing 20 mA current. Light brown





Ethylcyanoacetate +1,10-phenanthroline – Bi(+) system:-

Electrolysis of solution of 2.0 mL of ethylcyanoacetate, 1.0 g of

1,10-phenanthroline, 1.0 g of tetrabutylammonium chloride in 250 ml of

76







vacuum.

Ethylacetoacetate +1,10-phenanthroline – Bi(+) system:-

The solution of 2.0 mL of ethylacetoacetate, 1.0 g of 1,10-








Diethylmalonate +1,10-phenanthroline – Bi(+) system:-

In H-type cell 2.0 mL of diethylmalonate, 1.0 g of 1,10-



anode and platinum cathode by passing 20 mA current. After electrolysis

of one hour, light brown coloured product started separating in the


77



Acetylacetone + 2,2′-bipyridyl- Bi(+) system:-

The solution containing 2.0 mL of acetylacetone, 1.0 g of 2,2΄-




After electrolysis of one hour, light brown coloured solid product





2-Cyanoacetamide + 2,2′-bipyridyl– Bi(+) system:-

The solution containing 2.0 mL of 2-cyanoacetamide, 1.0 g of

2,2΄-bipyridyl, 1.0 g of tetrabutylammonium chloride dissolved in 250


electrolysed at bismuth anode and platinum cathode by passing a

current of 20 mA. After electrolysis of one hour, light brown coloured

solid product started separating in the anode compartment. The reaction

mixture was electrolysed for twelve hours and the product so obtained



78

Ethylcyanoacetate + 2,2′-bipyridyl– Bi(+) system:-

In H-type cell 2.0 mL of ethylcyanoacetate, 1.0 g of 2,2΄-bipyridyl,



cathode by passing 20 mA current. After electrolysis of one hour, light

brown coloured solid product separated in the anode compartment. The




vacuum.

Ethylacetoacetate + 2,2′-bipyridyl– Bi(+) system:-

In the electrolytic cell 2.0 mL of ethylacetoacetate, 1.0 g of 2,2΄-




stirring. After electrolysis of one hour, light brown coloured solid product





Diethylmalonate + 2,2′-bipyridyl– Bi(+) system:-

2.0 mL of diethylmalonate, 1.0 g of 2,2΄-bipyridyl,1.0 g of



79







80

e) Electrochemical Reactions of Various Aldehydes and Ketones at

Bismuth Anode.

Acetaldehyde - Bi(+) system:-

2.0 mL of acetaldehyde, 1.0 g of tetrabutylammonium chloride

and 250 ml of acetonitrile was taken in the electrolytic cell. Bismuth


dipped in cathode compartment. Both the electrodes were connected to

the source of direct current power supply. The potential across the


cell. The solution was stirred continuously. Solid product separated in

the anode compartment after one hour of electrolysis. After the

electrolysis of twelve hours, brown solid product was separated in the

anode compartment. The solution was filtered in glass filtration unit of

G-3 porosity. The product obtained was washed repeatedly with

acetonitrile and dry ether than dried under vacuum.

Propionaldehyde - Bi(+) system:-

The electrolysis of solution containing 2.0 mL of propionaldehyde,



passing 20 mA current. As the electrolysis proceeded solid product




81

Salicylaldehyde - Bi(+) system:-

The electrolysis of solution containing 2.0 mL of salicylaldehyde,



passing 20 mA current. As the electrolysis proceeded solid product




Benzaldehyde - Bi(+) system:-

Electrolysis of 2.0 mL of benzaldehyde, 1.0 g of



mA current. As the electrolysis proceeded, light brown solid product





Cinnamaldehyde - Bi(+) system:-

Electrolysis of 2.0 mL of cinnamaldehyde, 1.0 g of



mA current. As the electrolysis proceeded, light brown solid product



82



Acetone – Bi(+) system:-

In the electrolytic cell 2.0 mL of acetone, 1.0 g of

tetrabutylammonium chloride and 250 ml of acetonitrile was taken. The


passing a current of 20 mA. After one hour of electrolysis, dark brown





vacuum. Butan-2-one – Bi(+) system:-

2.0 mL of butan-2-one, 1.0 g of tetrabutylammonium chloride

and 250 ml of acetonitrile was taken in H-type cell and the solution was


current. Light brown coloured product started separating in the anode




Isobutylmethylketone – Bi(+) system:-

The reaction mixture containing 2.0 mL of isobutylmethylketone,



and platinum cathode by passing 20 mA current. Dark brown coloured

83





Coordination Compounds of Bi (III) Aldehydes/Ketones

The product of aldehydes/ketones - Bi(+) system (0.500 g) was

refluxed with 0.500 g of the ligand in various solvents like methanol,

ethanol, benzene and acetonitrile. The product was filtered after

refluxing the mixture for 48 hours. It was then washed with the same

solvent and dry ether and dried under reduced pressure.

Acetaldehyde +1,10-phenanthroline - Bi(+) system:-

In the electrolytic cell 2.0 mL of acetaldehyde, 1.0 g of 1,10-




electrolysis, brown coloured solid product separated in the anode




dried under vacuum.

Propionaldehyde +1,10-phenanthroline - Bi(+) system:-

The reaction mixture containing 2.0 mL of propionaldehyde, 1.0 g

of 1,10-phenanthroline 1.0 g of tetrabutylammonium chloride and 250


84


current. Brown coloured product started separating in the anode




Salicylaldehyde +1,10-phenanthroline – Bi(+) system:-

The solution of 2.0 mL of salicylaldehyde, 1.0 g of 1,10-








Benzaldehyde +1,10-phenanthroline - Bi(+) system:-

Electrolysis of 2.0 mL of benzaldehyde, 1.0 g of 1,10-


acetonitrile was carried out in H-type cell using bismuth anode and


proceeded, light brown solid product started separating in the anode




pressure.

85

Cinnamaldehyde +1,10-phenanthroline – Bi(+) system:-

Electrolysis of solution of 2.0 mL of cinnamaldehyde, 1.0 g of

1,10-phenanthroline, 1.0 g of tetrabutylammonium chloride in 250 ml of







vacuum.

Acetone +1,10-phenanthroline – Bi(+) system:-

In H-type cell 2.0 mL of acetone, 1.0 g of 1,10-phenanthroline,

1.0 g of tetrabutylammonium chloride was dissolved in 250 ml of

acetonitrile and the solution was electrolysed at bismuth anode and


hour, dark brown coloured product started separating in the anode


and was filtered, washed with acetonitrile and dry ether repeatedly and

then dried under vacuum.

Butane-2-one +1,10-phenanthroline – Bi(+) system:-

Electrolysis of solution of 2.0 mL of butane-2-one, 1.0 g of 1,10-




86





vacuum.

Isobutylmethylketone +1,10-phenanthroline – Bi(+) system:-

In H-type cell 2.0 mL of isobutylmethylketone, 1.0 g of 1,10-


acetonitrile solvent was taken and the solution was electrolysed at



after electrolysis of one hour. In order to obtain a sufficient amount of

the product, the reaction mixture was electrolysed for twelve hours and


dried under vacuum.

Acetaldehyde + 2,2′-bipyridyl- Bi(+) system:-

2.0 mL of acetaldehyde, 1.0 g of 2,2′-bipyridyl, 1.0 g of



compartment and platinum guage was dipped in the cathode




was stirred continuously. After electrolysis of one hour, light brown

87






Propionaldehyde + 2,2′-bipyridyl- Bi(+) system:-

2.0 mL of propionaldehyde, 1.0 g of 2,2΄-bipyridyl, 1.0 g of




Light brown coloured solid product was separated in the anode





Salicylaldehyde + 2,2′-bipyridyl– Bi(+) system:-

The solution containing 2.0 mL of salicylaldehyde, 1.0 g of 2,2΄-

bipyridyl, 1.0 g of tetrabutylammonium chloride dissolved in 250 ml of



After electrolysis of one hour, brown coloured solid product started


electrolysed for twelve hours and the product so obtained which was

88


under vacuum.

Benzaldehyde + 2,2′-bipyridyl- Bi(+) system:-

2.0 mL of benzaldehyde, 1.0 g of 2,2΄-bipyridyl, 1.0 g of




of one hour, brown coloured solid product separated in the anode




Cinnamaldehyde + 2,2′-bipyridyl- Bi(+) system:-

The solution containing 2.0 mL of cinnamaldehyde, 1.0 g of 2,2΄-









Acetone + 2,2′-bipyridyl– Bi(+) system:-

In H-type cell 2.0 mL of acetone, 1.0 g of 2,2΄-bipyridyl, 1.0 g of


89


passing 20 mA current. After electrolysis of one hour, dark brown





vacuum. Butan-2-one + 2,2′-bipyridyl– Bi(+) system:-

2.0 mL of butan-2-one, 1.0 g of 2,2΄-bipyridyland1.0 g of









Isobutylmethylketone + 2,2′-bipyridyl– Bi(+) system:-

In the electrolytic cell 2.0 mL of isobutylmethylketone, 1.0 g of




stirring. After electrolysis of one hour, light brown coloured solid product



90



91

e) Electrochemical Synthesis of Organobismuth Compounds

Bromoethane – Bi(+) system:-

2.0 mL of bromoethane, 1.0 g of tetrabutylammonium chloride

was dissolved in 250 ml of acetonitrile. The solution was taken in H-type

cell, which was then electrolysed at bismuth anode and platinum

cathode by passing a current of 20 mA. Light brown coloured solid

product was separated in the anode compartment after electrolysis of

one hour. The reaction mixture was electrolysed for twelve hours to



1-Bromopropane – Bi(+) system:-

The solution containing 2.0 mL of 1-bromopropane, 1.0 g of




hour, dark brown coloured solid product separated in the anode

compartment. The reaction mixture was electrolysed for twelve hours to



1-Chlorobutane – Bi(+) system:-

The solution containing 2.0 mL of 1-chlorobutane, 1.0 g of




92

one hour, light brown coloured solid product started separating in the




Chlorobenzene – Bi(+) system:-

In H-type cell 2.0 mL of chlorobenzene, 1.0 g of



passing 20 mA current. After electrolysis of one hour, dark brown





vacuum.

Cyclopentadiene – Bi(+) system:-

Dicyclopentadiene (Fluka) was broken down to cyclopentadiene

by refluxing it for eight hours and then distilled cyclopentadiene was

kept in a tight stoppered bottle.

In the electrolytic cell 2.0 mL of cyclopentadiene, 1.0 g of




hour, dark brown coloured solid product separated in the anode


93



dried under vacuum.

Coordination Compounds of Organobismuth Compounds

The product of organobismuth compounds (0.500 g) was refluxed

with 0.500 g of the ligand in various solvents like methanol, ethanol,

benzene and acetonitrile. The product was filtered after refluxing the

mixture for 48 hours. It was then washed with the same solvent and dry

ether and dried under reduced pressure.

Bromoethane +1,10-phenanthroline - Bi(+) system:-

2.0 mL of bromoethane, 1.0 g of 1,10-phenanthroline, 1.0 g of









1-Bromopropane +1,10-phenanthroline - Bi(+) system:-

2.0 mL of 1-bromopropane, 1.0 g of 1,10-phenanthroline, 1.0 g of




94

electrolysis of one hour, light brown coloured solid product separated in




1-Chlorobutane +1,10-phenanthroline – Bi(+) system:-

Electrolysis of the solution of 2.0 mL of 1-chlorobutane, 1.0 g of


of acetonitrile was conducted by passing 20 mA current. Dark brown





Chlorobenzene +1,10-phenanthroline – Bi(+) system:-

2.0 mL of chlorobenzene, 1.0 g of 1,10-phenanthroline,1.0 g of



and platinum cathode by passing a current of 20 mA. Light brown


hour of electrolysis. The solution was electrolysed for twelve hours. The

product obtained was filtered, washed with acetonitrile and dry ether


Cyclopentadiene +1,10-phenanthroline – Bi(+) system:-

In the electrolytic cell 2.0 mL of cyclopentadiene, 1.0 g of 1,10-


95



electrolysis, dark brown coloured solid product separated in the anode




dried under vacuum.

Bromoethane + 2,2′-bipyridyl- Bi(+) system:-

The solution of 2.0 g of bromoethane, 1.0 g of 2,2΄-bipyridyl, 1.0

g of tetrabutylammonium chloride in 250 ml of acetonitrile was taken in

H – type cell and was electrolysed at bismuth anode and platinum

cathode by passing 20 mA current with efficient stirring. After

electrolysis of one hour, dark brown coloured product started separating

in the anode compartment. The reaction mixture was electrolysed for ten



1-Bromopropane + 2,2′-bipyridyl- Bi(+) system:-

2.0 mL of 1-bromopropane, 1.0 g of 2,2′-bipyridyl, 1.0 g of



compartment and platinum gauge was dipped in the cathode




96

was stirred continuously. After electrolysis of one hour, light brown






1-Chlorobutane + 2,2′-bipyridyl- Bi(+) system:-

2.0 mL of 1-Chlorobutane, 1.0 g of 2,2΄-bipyridyl, 1.0 g of




of one hour, dark brown coloured solid product separated in the anode




Chlorobenzene + 2,2′-bipyridyl- Bi(+) system:-

2.0 mL of chlorobenzene, 1.0 g of 2,2΄-bipyridyl, 1.0 g of




Light brown coloured solid product was separated in the anode



97



Cyclopentadiene + 2,2′-bipyridyl- Bi(+) system:-

The solution containing 2.0 mL of cyclopentadiene, 1.0 g of 2,2΄-









98

PART (C)

Procedure for Chemical Analysis and Determination of

Current Efficiencies

Elemental Analysis:-

The elemental analysis (carbon, hydrogen, nitrogen, chlorine and

bromine) of the products of the various electrochemical reactions has

been carried out by using Perkin Elmer 2400 CHN elemental analyzer.

(a)Estimation of Bismuth:-

Bismuth contents present in the products prepared

electrochemically were determined volumetrically by oxine method179 as

discussed below:

Accurately weighed amount of the product (0.0500 g) was heated

to dryness ten times with 5.0 mL of fuming nitric acid. The dry mass was

then dissolved in water and 5.0 mL of hydrochloric acid. The solution

was boiled for five minutes and and then diluted to 25 mL in measuring

flask (solution ‘A’).

Preparation of oxine solution:-

2.0g of 8-hydroxyquinoline (oxine) was dissolved in 100mL of 2M

acetic acid and then ammonia solution was added dropwise till a

turbidity persisted in the solution and this mixture was heated to make

the solution clear.

To solution ‘A’ excess of warm solution of oxine (1 mL of oxine

precipitate 0.009675 g of Bi) was added alongwith a few drops of

99

concentrated ammonium acetate solution which completed the

precipitation. These precipitates were allowed to cool for half an hour

and the precipitates were filtered in G-3 sintered glass crucible and

washed repeatedly with hot water. These precipitates were dissolved in

2.0 mL of hydrochloric acid and made the volume 25 mL with distilled

water (solution ‘B’).

Preparation of 0.1 N potassium bromate solution:-

Potassium bromate (99.9%) was dried at 120° C. 2.7833 g of it

was dissolved in 1.0 L of solution in order to prepare 0.1 N solution.

Preparation of 0.1 N potassium iodate solution:

Potassium iodate (99.9%) was dried at 120° C. 3.5667 g of pure

dry potassium iodate was dissolved in 1.0 L of solution.

Preparation of 0.1 N sodium thiosulfate solution:-

24.80 g of sodium thiosulfate was dissolved in 1.0 L of

solution179. For standardization of sodium thiosulfate solution, 25 mL

0.1 N potassium iodate solution was taken. To this was added 2.0 g of

potassium iodide and 5.0 mL of 1 M sulfuric acid. The liberated iodine

was titrated against 0.1 N sodium thiosulfate solution with constant

shaking. When colour of solution changed to pale yellow, then the

solution was diluted to 200 mL and 2.0 mL of starch solution was added

to give blue colour and the solution was again titrated until the colour

changed from blue to colourless.

Titration:

100

To 10 mL of the solution ‘B’ was added two drops of methyl

orange indicator and 0.500 g of potassium bromide. It was titrated

against 0.1 N potassium bromate, the turbidity appeared during the

titration due to addition of excess of potassium bromate which was

removed by adding excess of 2M hydrochloric acid. To the above clear

solution 10 mL of 10% potassium iodide solution was added. It was

finally titrated against 0.1 N sodium thiosulfate solution using starch as

an indicator.

Calculation:

Let the volume of 0.1 N KBrO3 used = ‘x’ mL

Volume of 0.1 N hypo used = ‘y’ mL

Exact volume of 0.1 N KBrO3 solution used = x-y = ‘z’ mL

In this titration

12000 mL of 1 N BrO¯3 = 208.980 g Bi3+

1 mL of 1 N BrO¯3 = 208.980/12000 g Bi3+

1 mL of 0.1 N BrO¯3 = 208.980/12000 × 10 g Bi3+

z mL of 0.1 N BrO¯3 = 208.980 × z/12000 × 10 g Bi3+

= a g (say)

Thus the amount of Bi in 10 mL of solution ‘B’ = a g of Bi

The amount of Bi in 25 mL of solution ‘B’ = a × 25/10 g = 2.5a g of Bi

Percentage of Bi = 2.5a × 100/amount of sample (g)

101

(b) Estimation of Chlorine and Bromine:-

Chlorine and Bromine contents present in the products prepared

electrochemically were determined volumetrically by Mohr’s titration

method179

Preparation of solution:-

Accurately weighed amount of sample (0.0250 g) was placed in

nickel crucible containing fusion mixture, which was again covered with

layer of fusion mixture (mixture of anhydrous sodium carbonate and

potassium carbonate).

Then the crucible was heated on blower for 10 minutes so that

halide ion got freed in the mixture. The mixture was dissolved in water

and nitric acid was also added to get a clear solution, which was made

25 mL (sample solution).

Preparation of standard silver nitrate solution:-

0.1 N silver nitrate solution was prepared by adding 1.6900 g of

silver nitratein 100 mL of the solution and then the solution was

standardized by titrating against 0.1 N KCl solution using potassium

dichromate as indicator.

To the 10 mL of the sample solution taken in titration flask,

1.0 mL of potassium chromate solution (5.0 g of potassium chromate in

100 mL of solution) was added as indicator and it was titrated against

0.1 N silver nitrate solution. The addition of 0.1 N silver nitrate was

made till a faint reddish brown colour persisted after brisk shaking.

102

Calculation:-

Volume of sample solution taken= 10 mL

Normality of solution = 0.1 N

Let volume of AgNO3 solution used = ‘z’ mL

Weight of sample taken = w = 0.025 g

1000 mL of 1 N AgNO3 = Equivalent weight of halide ions (Ex)

Z mL of 0.1 N AgNO3 = Ex × z × 0.1/1000

= ‘b’ (say)

Percentage of halide = b × 25 ×100/10 w

103

(c) Determination of Current efficiency:-

The electrolysis was carried out in electrolytic cell using

bismuth anode and platinum cathode for two hours with identical

conditions as discussed above for all systems at constant current of

20 mA. The solution in anodic compartment was taken out. The anode

compartment of the cell and anode was washed three times with

acetonitrile. The solution of the anode compartment along with its

washings was distilled in the rotary film evaporator until 10 mL of

contents was left in the flask. The contents were then transferred to

beaker and heated to dryness. The compound was then broken with

concentrated nitric acid four times as discussed above. The quantity of

bismuth was determined volumetrically by oxine method179. The

calculations to determine current efficiency were done using Faraday’s

first law of electrolysis as given below:

Calculation:-

Experimental amount of Bi found = ‘a’ g (say)

Quantity of electricity passed = t × I/1000 coulombs

Where, t is time in seconds and I is current in milliamperes.

Theoretical amount of Bi dissolved by passing above quantity of

electricity = t × I × 208.980/1000 × 96487 × 3 g

= ‘b’ g (say)

Current efficiency = a/b g equivalent faraday -1

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