Prof. Nagwa Nawwar

- Mohammed El-Desoki Shalaby .- Mahmoud Mohamed El-Sharkawy .- Mohammed Ahmed Zaki Glalah.- Ahmed Mohammed saad .- Mohammed Osama Hais .

These group consist of 3 elements

Mn1- Manganese

Tc2- Technetium

3- Rhenium Re

RheniumTechnetiumManganeseElement

transition metal transition metal transition metal Classification

silvery-whitesilver-gray gray-white Color

186.2079854.9380Atomic weight

solidsolidsolidState

3186 oC, 3459 K2160 oC, 2433 K 1250 oC, 1523 K Melting point

5596 oC, 5869 K 4260 oC, 4533 K 2060 oC, 2333 K Boiling point

[Xe] 4f14 5d5 6s2[Kr] 4d6 5s1[Ar] 3d5 4s2Electron configuration

21.0 g/cm311.5 g/cm37.43 g/cm3Density

d5s2For these group is Electron configuration

So(1) the highest oxidation state for these group is+ 7,

(2) Mn Takes a large extent of oxidation states starting from -3 and even +7.

(3) +2 Oxidation state of manganese is the most stable and the most common.

There are Mn +2 in the solid state and liquid in the complexes.

- In alkaline Mn oxidized Mn2 + (2+) to manganese dioxide MnO2.

Mn2+ oxidation MnO2

Oxidation state +4 exist in the main raw manganese and called pyrolusite MnO2.

Used as a catalyst in the preparation of O2 from KClO3

ALSO USED AS OXIDIZING AGENT

NaOH Na2[MnO4]

Mn2+ oxidation MnO2 “amphoteric oxide”

MnCl2+ Cl2 + H2O

HCl

Manganese +7

known such as potassium permanganate, KMnO4, which is considered one of the most powerful oxidizing agents in solution and Mn +3 and Mn +4 disintegrate by heat .

The low oxidation state in carbonyl compounds or derivatives of carbonyl complexes.

*Unlike the case of +7 for Mn, which have high oxidant properties , the oxidation state +7 for each of [Tc] and [Re] are the most common and the most stable and has a weak oxidant properties.

Oxidation state +6

Disintegrate thermally but unknown. Oxidation states +5, +6 have chemistry recognized by each of the technetium and rhenium.

Extraction of (Mn-Tc-Re):

(1) Manganese:- The most important manganese ore is pyrolusite (MnO2) or (MnO4) &

we can get it by reduction process by Al

3MnO2 reduction Mn2O3+O2

3Mn2O3+8Al 9Mn+4Al2O3

(2)Techneium:- Nearly all technetium is produced synthetically, and only minute

amounts are found in nature.

Naturally occurrence of technetium as a spontaneous fission productin uranium ore or by neutron capture in molybdenum ores.

Remain nuclear fuel O2 Tc2O7 (volatile) .

(3)Rhenium:-

Rhenium is considered as rarely element & is found in the remains of molybdenum ore .

Mo ignition product (washing ,filtrate then oxidize & precipitate by

adding any salt contain K)

Note that:-

No ionic compounds for each of Technetium and Rhenium except of bertknat TcO4 (2- )and brairinat ReO4 (2-)

Applications & Uses of Manganese : manganese dioxide has been used to make colorless glass.

Manganese dioxide is also used as a black-brown pigment in paint and as a filler in dry cell batteries.

The great majority of manganese ore ends up in steel production where the manganese desulfurizes and deoxidizes the steel.

It is also is used extensively to produce a variety of important alloys For example, the aluminum used to make most soft drinks cans contains about 1% manganese to improve the cans’ stiffness and corrosion resistance.

Methylcyclopentadienyl manganese tricarbonyl is used as an additive in unleaded gasoline to boost octane rating and reduce engine knocking

In the human body several enzymes containing manganese are need to metabolize carbohydrates, cholesterol, and amino acids

Applications & Uses of Technetium:

Nuclear medicine and biology is used in radioactive isotopemedical tests(radioactive tracer)

-Technetium-99m emits gamma rays and low energy electrons, forming technetium-99 (half-life 211 000 years). The gamma rays can be photographed using a gamma camera.

Industrial and chemical Technetium-99 has also been proposed for use in

optoelectronic devices and nanoscale nuclear batteries. technetium can serve as a catalyst. For some reactions,

for example the dehydrogenation of isopropyl alcohol. adding a small concentration (55 ppm) of potassium

pertechnetate(VII) to the water protects the steel from corrosion.

Applications & Uses of Rhenium:

Rhenium is added to high-temperature superalloysthat are used to make jet engine parts.

Another major application is in platinum-Rhenium catalysts, which are primarily used in making lead-free, high-octane gasoline.

The nickel-based superalloys have improved creep strength with the addition of Rhenium,these alloys

were used in the engines of the F-16 and F-15(Military Plane)

The isotopes 188Re and 186Re are

radioactive and are used for

treatment of liver cancer.

188Re is also being used

experimentally in a novel treatment

of pancreatic cancer where it is delivered by means of the bacterium Listeria monocytogenes .