Chemistry of ElementsCHEM-E4130 (5 cr)

Lectures (11 x): Monday 10.00 – 12.00Wednesday 10.00 – 12.00Friday 10.00 – 12.00

Lecturers: Maarit KarppinenAntti KarttunenOtto MustonenChris Thomas

B202b

The course covers the basics of the chemistry of elements.Emphasis on the d-block transition metals, lanthanoids and actinoidsAfter the course the student will be able to:1. Explain the basic features of the transition metal chemistry

2. Derive the basic chemical and physical properties of d-block and f-blocktransition metals from their electron structures

3. Name the coordination compounds and describe their structures

4. Describe the most important compounds of transition elements and nametheir applications

5. Find and read basic scientific literature on a given topic related to thechemistry of elements

MARKINGÿExam 50 points: min. 10 pÿ Lecture exercises 25 points:

10 x 2.5 p; min. 10 pÿSeminar 25 points:

15 – 25 p; min. 15 p

REFERENCE BOOKS

n Descriptive Inorganic Chemistry,G. Rayner-Canham & T. Overton,W.H. Freeman and Company.

n Chemistry of the Elements, N.N.Greenwood & A. Earnshaw,Pergamon Press.

n Inorganic Chemistry,C.E. Housecroft & A.G. Sharpe,Pearson.

ß Lectures: 11 x ca. 2 hß Home problem solving 40 hß Independent homework 60 hß Exam 3 h

LECTURE SCHEDULE

Date Topic

1. Mon 31.10. Review of Elements, Periodic Properties & Periodic Table

2. Wed 02.11. Short Survey of the Chemistry of Main Group Elements

3. Fri 04.11. Redox Chemistry (Mustonen)

4. Fri 11.11. Transition Metals: General Aspects & Crystal Field Theory (Thomas)

5. Wed 16.11. Ag, Au, Pt, Pd & Catalysis (Karttunen)

6. Fri 18.11. Zn + Ti, Zr, Hf & Atomic Layer Deposition (ALD)

7. Mon 21.11. Cr, Mo, W & Metal Complexes

8. Wed 23.11. Mn, Fe, Co, Ni, Cu & Magnetism and Superconductivity (Mustonen)

9. Mon 28.11. Resources of Elements & Rare/Critical Elements &Element Substitutions

10. Wed 30.11. Lanthanoids + Actinoids & Luminescence

11. Fri 02.12. Inorganic materials chemistry research

EXAM ??

QUESTIONS: Lecture 1

1. Why copper readily exists in the oxidation state +I ? Give the electronconfiguration for Cu.

2. How many f electrons atoms of the following elements have: La, Eu, Lu ?

3. How many f electrons the following ions have: La3+, Eu3+, Eu2+ ?

4. How many unpaired electrons the following ions have:V5+, Cr3+, Cu2+, Eu3+, Tb3+, Yb3+, Lu3+ ?

5. Indicate the larger atom/ion in the following pairs:Na–K, K–Ca, Fe2+–Fe3+, Ti3+–Ti4+, Ti4+–Zr4+, Zr4+–Hf4+, La–Lu

1 18

2 13 14 15 16 17

3 4 5 6 7 8 9 10 11 12

Alkali metalsAlkaline earth metalsHalogensNoble gases

Transition metalsLanthanidesActinides

http://www.chemicool.com/cgi-bin/imagemap/Projects/Chemicool/pertable.map

TRANSITION METALS

ß A variety of possible oxidation states and spin-configurationsÆ exciting properties

ß d-block transition metalsÿ [Sc ~ Cu(Zn)] + [Y ~ Ag(Cd)] + [La ~ Au(Hg)]

ß f-block transition metalsÿ lantanides [14 elements after La: Ce ~ Lu]ÿ actinides [14 elements after Ac: Th ~ Lr]ÿ lantanoides (Ln): La + Lantanidesÿ rare earth elements (RE): Ln + Y + Sc

Which element(s) was/were discoveredß as a result of huge interest in burning reactions in 1700sß based on accurate measurements of air in 1890sß thanks to the progress in electrochemical techniques in 1800-1810ß thanks to the progress in spectroscopy techniques in 1860sß much earlier in South America by native Indians than in Europe (in 1750~1850)ß based on quantum chemical considerationsß by a Finnish professorß the discovery was rewarded by a Nobel prize in 1906

http://www.smithsonianmag.com/smart-news/the-periodic-table-of-elemental-discoveries-1773011/

OXYGEN and NITROGEN

ß Discovered related to investigations related to air and burningin the end of 18th century (Priestley, Scheele, Lavoisier)

ß Oxygen (O): Greek oxys genes (= acid forming)ß Nitrogen (N): Greek nitron genes (= nitrate forming)

NOBLE GASES

n All stable noble gases found in the end of 19th century by Ramsayand Rayleigh through accurate measurements/experiments of air

n Element Year Origin of name

Argon (Ar) 1894 Greek argon (= inert)Krypton (Kr) 1898 Greek krypton (= hidden)Neon (Ne) 1898 Greek neos (= new)Ksenon (Xe) 1898 Greek xenon (= strange)

ALKALI and ALKALINE EARTH METALS(mostly through electrochemistry)

n Sodium (Na): Lat. natrium;Compounds known since ancient times,preparation in metallic form by Davy in 1807

n Potassium (K): Lat. kalium, Arab. qali (= base); Davy 1807n Lithium (Li): Greek lithos (= stone); Arfwedson 1817n Magnesium (Mg): Greek Magnesia (name of a place)n Calcium (Ca): Lat. calx (= Chalk); Davy 1808n Barium (Ba): Greek baryta (= heavy);

Scheele showed in 1774 that the oxide made frombaryte (raskassälpä) is different from calcium oxide,preparation in metallic form by Davy in 1808

n Strontium (Sr): Strontia (Scottish town);Hope siscovered in 1791 from Scotland (SrSO4mineral), metallic form by Davy in 1808

n Beryllium (Be): Greek beryllosVauguelin discovered in 1798 from beryllos mineral,preparation in metallic form in 1828 (reduction by K)

ELEMENTS DISCOVERED by means of SPECTROSCOPYn Cesium (Cs): Lat. caesius (= sky blue);

Bunsen and Kirchoff in 1860 from mineral water,separation twenty years later

n Rubidium (Rb): Lat. rubidius (= deep red);Bunsen and Kirchoff in 1861

n Thallium (Tl): Greek thallos (= green spring); Crookes 1861

n Indium (In): indigon (blue/violet); Reich and Richter 1863

n Helium (He): Greek helios (= sun);only element discovered first (Janssen 1868;spectrum of the Sun) outside of the Earth (1895)

PLATINUM METALS

n Known in South America (native Indians used in jewelry)much before “discovered” in Europe

n Element Discoverer Origin of name

Platinum (Pt) de Ulloa 1748 Spanish platinaPalladium (Pd) Wollaston 1803 Pallas (asteroid)Osmium (Os) Tennart 1803 Greek osme (= smell)Iridium (Ir) Tennart 1803 Lat. iris (= rainbow)Rhodium (Rh) Wollaston 1804 Greek Rhodon (= rose)Rutenium (Ru) Claus 1844 Lat. Rutenia (= Russia)

HALOGENSn Chlorine (Cl): Greek kloros (= yellowish green);

Scheele 1774: oxidation of HCl,Davy 1807: nature of an element

n Iodine (I): Greek iodes (= violet);Courtois found iodine from seaweed ash

n Bromine (Br):Greek bromos (= to stink (bad smell));Balard found in 1861 from salt solutions

n Fluorine (F): Lat. fluere (= to flow);Use of fluorspar in metallurgy (flux agent) known since 1500s;elemental fluorine discovered by Moissan in 1886through electrolysis of HF (Nobel 1906)

RARE EARTH ELEMENTS (= METALS)n Discovery history starts from and ends in Finland:

- Johan Gadolin (prof. at Univ. Turku) showed in 1794 that the new mineralfound in Ytterby (near Stockholm) contained some new oxide (“earth”) of anunknown/new element Æ yttrium- Olavi Erämetsä (inorg. chem. prof. at TKK) found in 1965 from nature smallamounts of radioactive promethium (first discovered as a fission product innuclear reactions in USA)

n Element Discoverer Origin of nameCerium (Ce) Klaproth 1803 Ceres (asteroid)Lanthanum (La) Mosander 1839 Greek lanthano (= to hide)Terbium (Tb) Mosander 1843 YtterbyErbium (Er) Mosander 1843 YtterbyYtterbium (Yb) Mariqnac 1878 YtterbyHolmium (Ho) Cleve 1878 Holmia (= Stockholm)Thulium (Tm) Cleve 1879 Thule (= Nothern country)Scandium (Sc) Nilson 1879 ScandinaviaSamarium (Sm) Boisboudran 1879 Samarskite (mineral)Gadolinium (Gd) Marignac 1880 Johan GadolinPraseodymium (Pr) Welsbach 1885 Greek didymos (= green twin)Neodymium (Nd) Welsbach 1885 Greek neos didymos (= new twin)Dysprosium (Dy) Boisboudran 1886 Greek dysprositos prasios (= difficult to reach)Europium (Eu) Demarcay 1896 EuropeLutetium (Lu) Urbain 1907 Lutetia (= Paris)

IUPAC (International Union of Pure and Applied Chemistry)n Based on the Greek/Latin names of numbers

n For example: element no. 119: un un enn Æ Ununennium (Uue)

Number Name Number Name

0 nil 5 pent

1 un 6 hex

2 bi 7 sept

3 tri 8 oct

4 quad 9 enn

Z = 113: nihonium NhZ = 115: moscovium McZ = 117: tennessine TsZ = 118: oganesson Og

Nuclear fusion: Dubna, RIKEN, OakRidge

RELATIVE ABUNDANCE OF ELEMENTS (in universe)• H 88.6 at-%, He 11.3 at-%• Abundance decreases exponentially with atomic number Z• Even numbers (o) more common than odd numbers (∑)• So far discovered: Z = 1 – 118• In nature: from H (Z = 1) to U (Z = 92);

only trace amounts of radioactive Tc (Z = 43) ja Pm (Z = 61)• Nuclear reactions: Z = 93 – 118

MAGIC NUMBERS

n In nucleus fixed energy levels for protons and neutrons (c.f. electrons & orbitals)n With certain atomic numbers (Z) and neutron numbers (N) more stable nucliin So-called magic nuclii: Z or N = 2, 8, 20, 28, 50, 82, 126n Double magic nuclii: 4He (Z = 2), 16O (Z = 8), 208Pb (Z = 82)

Artificial Elements

n Preparation: fusionreactions of nuclii inparticle accelerators(Dubna, RIKEN,OakRidge, Hamburg)

n Life times typicallyless than second

n 1937: first artificiallyprepared element:Technetium (Tc) (Greekteknetos = artificial)

ISOTOPES

n Known atoms (273 stable + radioactive) much more than elements (118)Æ many elements have different atoms Æ ISOTOPES

n Isotopes of the same element are chemically similar but the physicalproperties may be different

n With increasing atomic number Z the relative number of neutronsincreases

n Natural isotope composition nearly constant for stable elements butvaries for radioactive elements

ATOMIC WEIGHTSn Accuracy is continuously increasing

SOURCES OF ERROR IN ATOMIC WEIGHTS

n accuracy of measurementn natural isotope composition (B, S)n ”depleted” elements (in natural Li 7.5% 6Li, commercially only 3.75 %)n enriched elements (from nuclear reactors)n radioactive elements (atomic weight changes as a function of time)

LITHIUM ISOTOPES

n Naturally occurring lithium is composed of two stable isotopes: 6Li and 7Li (92.5 %)n Both natural isotopes have an uncommon property: nuclear fission is energycally

possiblen As a result of this lithium is much less common in the Solar System than expectedn Besides the two natural isotopes, seven unstable Li radioisotopes are known, the

most stable being 8Li (half-life of 838 ms)n The two natural isotopes separate substantially during various natural processes,

such as mineral formation, metabolism and ion exchangen For example: lithium ions substitute for octahedral magnesium and iron in clay

minerals, where 6Li is preferred to 7Li, resulting in enrichment of the lighter isotopein these minerals

n Manufacture of nuclear weapons and other uses in nuclear physics use 6Li:- source material for the production of tritium 3H- absorber of neutrons in nuclear fusion reactions

n 6Li is used by nuclear/military industry to such an extent as to slightly butmeasurably change the 6Li to 7Li ratios even in natural sources, such as rivers

n In commercial Li chemicals the 6Li content is often strongly lowered (7.5 → 3.75 %)

https://en.wikipedia.org/wiki/Lithium

IMPORTANT HISTORICAL STEPS• Thomson 1898-1903: existence of electrons• Rutherford 1911: small and dense nucleus + electron cloud• Einstein 1905: wave and particle nature of electromagnetic radiation• Bohr 1913: simple atom model (classical physics + some quantum theory features)• de Broglie 1924: wave nature of particles• Davisson & Germes 1927: diffraction of electrons• Heisenberg 1926: uncertainty principle (exact position and momentum of electron)• Schrödinger 1926:

wave nature of electrons Æ quantum mechanical atom model• Compton 1921 and Goudsmit & Uhlenbeck 1925: electron spin• Pauli 1925: “exclusion principle”• Hund 1925: minimum energy Æ maximum number of unpaired electrons

ATOMIC MODEL & ELECTRON CONFIGURATIONS

QUANTUM MECHANICAL ATOM MODEL

ß Electrons have simultaneously both wave and particle nature

ß In an atom electron behaves like standing wave

ß Schrödinger wave function:

ÿ wavefunction y is a solution of Schrödinger equation

ÿ y describes the behaviour of electron

ÿ in chemistry: wavefunction Æ atomic orbital

ÿ Schrödinger equation has several possible solutions (= orbitals)

ÿ each orbital is described with a set of three quantum numbers:n, l and m

ÿ There is a certain energy corresponding to each wave function

ÿ Energy quantization is derived from the Schrödinger equation

QUANTUM NUMBERSn l m Orbital Number1 0 0 1s 12 0 0 2s 1

1 -1, 0, 1 2p 33 0 0 3s 1

1 -1, 0, 1 3p 32 -2, -1, 0, 1, 2 3d 5

4 0 0 4s 11 -1, 0, 1 4p 32 -2, -1, 0, 1, 2 4d 53 -3, -2, -1, 0, 1, 2, 3 4f 7

Principal quantum number (n): 1, 2, 3, …- size and energy of the orbitalAngular momentum quantum number (l): 0, 1, … , (n-1)- shape of the orbitalMagnetic quantum number (m): -l, (-l+1), …, (+l-1), +l- orientation of the orbital in 3D spaceSpin quantum number (s): -½, ½

Pauli’s exclusion principle:In one atom it is impossible for two electrons to share the same setof the four quantum numbers, n, l, m and s

Aufbau (“building up”) principle:Orbitals are filled in the order of increasing energy:1s–2s–2p–3s–3p–4s–3d–4p–5s–4d–5p–6s–4f–5d–6p–7s–5f–6d–7p

Hund’s rule:Every orbital in a subshell is singly occupied with one electronbefore any one orbital is doubly occupied, and all electrons in singlyoccupied orbitals have the same spin(to minimize the electron-electron repulsions)

Atom orbitals• y (wave function):does not tell the location or path of electron(c.f. Heisenberg uncertainty principle)

• y2 (square of wave function):probability of electron to be located in a certain locationÆ PROBABILITY DENSITY / ELECTRON DENSITY MAPÆ ”shape” of the orbital

• RADIAL PROBABILITY DENSITY:most probable distance between electron and nucleus

s

d

p

f

PERIODIC TABLE

PERIODIC PROPERTIES

n effective nuclear chargen atomic radius and ionic radiusn ionization energyn electron affinityn electronegativityn oxidation numbersn densityn melting and boiling pointsn reactivity and stoichiometries of compoundsn properties of compoundsn etc.

EFFECTIVE NUCLEAR CHARGE (Zeff)ß Zeff: net positive charge experienced by an electron in a multi-electron atomß This charge is smaller than the real nuclear charge (Z) due to the shielding

effect of the other negatively charged electrons in the same atomß Shielding prevents the higher orbital electrons from experiencing the real

nuclear chargeß Zeff = Z – S (= shielding parameter)ß The shielding effect is never complete since the orbitals penetrate within each

other: +e < Zeff < Z

https://en.wikipedia.org/wiki/File:Effective_Nuclear_Charge.svg

IONIC RADIUSß It is not possible to measure ionic radius values

directlyß The values are estimated (using statistical techniques)

for each ion from a large data set for experimentallydetermined bond lengths in different ionic compounds

ß There are many different ionic radius tables, the mostcommonly used one is:

R.D. Shannon, Acta Cryst. A 32, 751 (1976)

O2-

Mg2+

Fe2+

Fe3+Ti4+

Cl-

Si4+

K+

Na+

B3+C4+

Ca2+

Al3+

earth-alkaline metals: oxidation state +II

CN 4 6 8 9 10 12

Be 0.27 0.45 - - - -

Mg 0.57 0.72 0.89 - - -

Ca - 1.00 1.12 1.18 1.23 1.34

Sr - 1.18 1.26 1.31 1.36 1.44

Ba - 1.35 1.42 1.47 1.52 1.66

Ionic radius[Å]

anions:CN = 6

OH-1.37

H-1.67

O2-1.40

F-1.33

S2-1.84

Cl-1.81

Se2-1.98

Br-1.96

Te2-2.21

I-2.20

3d cations: CN = 6Ox.

stateTi V Cr Mn Fe Co Ni Cu Zn

+II 0.86 0.79 0.80 0.83 0.78 0.75 0.69 0.73 0.74+III 0.67 0.64 0.62 0.65 0.65 0.61 0.60 0.54 -+IV 0.61 0.58 0.55 0.53 0.59 0.53 0.48 - -

Y3+

Sc3+

Ln3+

LANTHANOID CONTRACTION

SMALL SIZED CATIONn large charge/radius ratio

n polarizes easily anions

n outer (valence) shells overlap

n more covalent bond character(different properties)

n possibility to form p-bonds(double and tripple bonds,e,g. C =C, C ∫ C, N∫ N)

Zeff ª constant:IE and EN

increase, sinceratom decreases

Zeff increases, ratom decreases

Æ IE and EN increase

atomic radius (ratom)ionization energy (IE)electronegativity (EN)

n In compounds with OH groups, electronegativity of thecentral cation defines whether the compound is anoxoacid or a base

n large electronegativity: E-O-H Æ E-O- + H+ (happo)

n small electronegativity: E-O-H Æ E+ + OH- (emäs)

n For example: elements of the third period:

NaOH strong baseMg(OH)2 baseAl(OH)3 amfolyteSi(OH)4 weak acid [H4SiO4]OP(OH)3 acid [H3PO4]O2S(OH)2 strong acid [H2SO4]O3Cl(OH) strong acid [HClO4]

Electro-negativityincreases

SIMILARITIES BETWEEN THE ELEMENTS

n Within the groups in the Periodic Table the elements have the sameelectron configuration for the outer shellÆ same (possible) oxidation statesÆ similar chemical behaviour

n The group similarity is the clearest for the (main) groups 1, 2, 17 ja 18

n In each group the lightest element is clearly much smaller inatmic/ionic radii than the others, hence somewhat different from theothers in properties

n DIAGONAL RELATIONSHIP:The lightest element rather resembles the next lightes element of thenext group in the Periodic Table

n Examples of diagonal relationships:Li-Mg, Be-Al, B-Si, N-S

Electron configurations of 3d metals:1s22s22p63s23p64s23dx

3d 4sScandium (Sc) ≠ ≠ØTitanium (Ti) ≠ ≠ ≠ØVanadium (V) ≠ ≠ ≠ ≠ØChromium (Cr) ≠ ≠ ≠ ≠ ≠ ≠Manganese (Mn) ≠ ≠ ≠ ≠ ≠ ≠ØIron (Fe) ≠Ø ≠ ≠ ≠ ≠ ≠ØKoboltti (Co) ≠Ø ≠Ø ≠ ≠ ≠ ≠ØNikkeli (Ni) ≠Ø ≠Ø ≠Ø ≠ ≠ ≠ØKupari (Cu) ≠Ø ≠Ø ≠Ø ≠Ø ≠Ø ≠[Sinkki (Zn)] ≠Ø ≠Ø ≠Ø ≠Ø ≠Ø ≠Ø