IB Chemistry on Crystal Field Theory and Splitting of 3d orbital
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This document provides a tutorial on crystal field theory and the splitting of 3d orbitals. It discusses the periodic table and how elements are divided into s, p, d and f blocks based on which orbitals are partially filled. It focuses on d-block elements known as transition metals, which have partially filled d orbitals. Key topics covered include crystal field splitting, ionization energies, oxidation states, complex ion formation, ligand coordination, and the magnetic and catalytic properties of transition metals.
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IB Chemistry on Crystal Field Theory and Splitting of 3d orbital
- 1. http://lawrencekok.blogspot.com Prepared by Lawrence Kok Tutorial on Crystal Field Theory and splitting of 3d orbitals.
- 2. Periodic Table of elements – divided into s, p, d, f blocks p block • p orbital partially fill d block • d orbital partially filled • transition element f block • f orbital partially fill s block • s orbital partially fill
- 3. Periodic Table – s, p d, f block elements block elements • s orbitals partially fill p block elements • p orbital partially fill d block elements • d orbitals partially fill • transition elements 1 H 1s1 2 He 1s2 11 Na [Ne] 3s1 12 Mg [Ne] 3s2 5 B [He] 2s2 2p1 6 C [He] 2s2 2p2 7 N [He] 2s2 2p3 8 O [He] 2s2 2p4 9 F [He] 2s2 2p5 10 Ne [He] 2s2 2p6 13 Al [Ne] 3s2 3p1 14 Si [Ne] 3s2 3p2 15 P [Ne] 3s2 3p3 16 S [Ne] 3s2 3p4 17 CI [Ne] 3s2 3p5 18 Ar [Ne] 3s2 3p6 19 K [Ar] 4s1 20 Ca [Ar] 4s2 21 Sc [Ar] 4s2 3d1 22 Ti [Ar] 4s2 3d2 23 V [Ar] 4s2 3d3 24 Cr [Ar] 4s1 3d5 25 Mn [Ar] 4s2 3d5 26 Fe [Ar] 4s2 3d6 27 Co [Ar] 4s2 3d7 28 Ni [Ar] 4s2 3d8 29 Cu [Ar] 4s1 3d10 30 Zn [Ar] 4s2 3d10 n = 2 period 2 3 Li [He] 2s1 4 Be [He] 2s2 Click here video s,p,d,f blocks,Click here video on s,p,d,f notationClick here electron structure Video on electron configuration f block elements • f orbitals partially fill
- 4. 3d Nuclear charge increase IE increase slowly 3d elec added to 3d sub level 3d elec – shield the outer 4s elec from nuclear charge Ionization Energy – Transition metal Why IE increases slowly across ?IE Transition metal Sc Ti V Cr Mn Fe Co Period 4 Ni Cu Shielding nuclear charge by 3d electron +21 +22 +23 +24 +25 +26 +27 +28 +29 4s Sc Ti V Cr Mn Fe Co Ni Cu Zn +21 +22 +23 +24 +25 +26 +27 +28 +29 +30 Nuclear pull Shielding by 3d electron Shielding by 3d electron ↓ Balance increase in nuclear charge ↓ Small increase in IE ↓ Easier to lose outer electron ↓ Variable oxidation state
- 5. Transition Metal (d block ) Across period Cr - 4s13d5 • half filled more stable Cu - 4s13d10 • fully filled more stable Ca 4s2 K 4s1 Transition metal have partially fill 3d orbital • 3d and 4s electron can be lost easily • electron fill from 4s first then 3d • electron lost from 4s first then 3d • 3d and 4s energy level close together (similar in energy) Filling electron- 4s level lower, fill first Losing electron- 4s higher, lose first 3d 4s
- 6. d block element with half/partially fill d orbital / sublevel in one or more of its oxidation states Partially fill d orbital Lose electron ↓ Formation ions Sc3+ 4s03d0 Zn 2+ 4s03d10 Zn → Zn2+ 4s2 3d10 4s0 3d10 fully fill d orbital Sc → Sc 3+ 4s2 3d1 4s0 3d0 empty d orbital Transition Metal (d block ) NOT Transition element. NOT Transition element. О О
- 7. Transition Metal Physical properties Chemical properties Element properties Atomic properties • High electrical/thermal conductivity • High melting point • Malleable • Ductile • Ferromagnetic • Ionization energy • Atomic size • Electronegativity Transition Metal ( d block) Gp 1 Gp 17 Sc Ionization energy ↓ IE increase ↑ slowly ↓ Shielding of nuclear charge by 3d elec ↓ Electrostatic force attraction ↓ Atomic size ↓ Decrease ↓ slowly ↓ Shielding of outer electron from nuclear charge by 3d elec Electronegativity ↓ EN increase ↑ slowly Physical Properties Zn EN increase ↑ Atomic size decrease ↓ IE increase ↑ • Formation of complex ion • Formation coloured complexes • Variable oxidation states • Catalytic activity Formation complex ion Formation coloured complexes Catalytic activity Variable Oxidation states molecule adsorp on surface catalyst V Cr Mn Fe Co Ni +2 +2 +2 +2 +2 +2 +3 +3 +3 +3 +3 +3 +4 +4 +4 +4 +4 +4 +5 +5 +5 +5 +5 +6 +6 +6 +7
- 8. Transition Metal – Variable Oxidation States +3 +3 +3+3+3 +3 +2 +2 +2 +2 +2 +4 +4 +5 +2 +6 +6 +7 +2 +3 +4 +5 +6 +7 ScCI3 TiCI3 VCI3 CrCI3 MnCI3 FeCI3 CrCI2 MnCI2 FeCI2 CoCI2 NiCI2 CuCI2 ZnCI2 TiCI4 MnCI4V2O5 Cr2O7 2- +2 (VO2)2+ (MnO4)2- (MnO4)- oxides oxyanion chlorides +2 oxidation state more common+3 oxidation state more common +3 CoCI3 Oxidation state Mn highest +7 Highest oxidation state exist ↓ Element bond to oxygen (oxide/oxyanion) Oxidation state +2 common (Co → Zn) ↓ Harder to lose electron ↓ Nuclear charge (NC ↑) from Co - Zn Oxidation state +3 common (Sc → Fe) ↓ Easier to lose electron ↓ Nuclear charge (NC ↓) from Sc - Fe Transition metal – variable oxidation state ↓ 4s and 3d orbital close in energy ↓ Easy to lose electron from 4s and 3d level Ionic bond – more common for lower oxi states TiCI2 – Ionic bond Covalent bond – more common for higher oxi states TiCI4 – Covalent bond Highest oxidation states – bind to oxygen
- 9. Transition Metal Formation coloured complexes Variable Oxidation states Sc Ti V Cr Mn Fe Co Ni Cu Zn +1 +2 +2 +2 +2 +2 +2 +2 +2 +2 +2 +3 +3 +3 +3 +3 +3 +3 +3 +4 +4 +4 +4 +4 +4 +4 +5 +5 +5 +5 +5 +6 +6 +6 +7 +3- most common oxi state + 2- most common oxi state + 7- Highest oxi state Click here vanadium ion complexes Click here nickel ion complexes V5+/ VO2 + - yellow V4+/ VO2+ - blue V3+ - green V2+ - violet NiCI2 - Yellow NiSO4 - Green Ni(NO3)2 - Violet NiS - Black Diff oxidation states Colour formation Nature of transition metal Oxidation state Diff ligands Shape Stereochemistry Diff ligandDiff metals MnCI2 - Pink MnSO4 - Red MnO2 - Black MnO4 - - Purple Cr2O3 - Green CrO4 2- - Yellow CrO3 - Red Cr2O7 2- - Orange Shape/ Stereochemistry Tetrahedral Octahedral BlueYellow
- 10. Transition Metal ion • High charged density metal ion • Partially fill 3d orbital • Attract to ligand • Form dative/co-ordinate bond (lone pair from ligand) Ligand • Neutral/anion species that donate lone pair/non bonding electron pair to metal ion • Lewis base, lone pair donor – dative bond with metal ion Ligand +2 Formation complex ion Transition Metal ion Neutral ligand Anion ligand H2O NH3 CO CI– CN– O2- OH– SCN– : CI : :. Monodentate Bidentate Polydentate C2O4 2- C2H4(NH2)2 Drawing complex ion • Overall charged on complex ion • Metal ion in center (+ve charged) • Ligand attach • Dative bond from ligand +3 4 water ligand attach 4 dative bond Coordination number = 4 6 water ligand attach 6 dative bond Coordination number = 6 Transition metal + ligand = Complex Ion
- 11. Coordination number Shape Complex ion (metal + ligand) Ligand (charged) Metal ion (Oxidation #) Overall charge on complex ion linear [Cu(CI2)]- CI = -1 +1 - 1 [Ag(NH3)2]+ NH3 = 0 +1 + 1 [Ag(CN)2]- CN = -1 +1 - 1 Square planar [Cu(CI)4]2- CI = -1 +2 - 2 [Cu(NH3)4]2+ NH3 = 0 +2 +2 [Co(CI)4]2- CI = -1 +2 - 2 Tetrahedral [Cu(CI)4]2- CI = -1 +2 - 2 [Zn(NH3)4]2+ NH3 = 0 +2 + 2 [Mn(CI)4]2- CI = -1 +2 - 2 Octahedral [ Cu(H2O)6]2+ H2O = 0 +2 + 2 [Fe(OH)3(H2O)3] OH = -1 H2O = 0 +3 o [Fe(CN)6]3- CN = -1 +3 - 3 [Cr(NH3)4CI2]+ NH3 = 0 CI = -1 +3 + 1 Types of ligand: • Monodentate – 1 lone pair electron donor – H2O, F-, CI-, NH3, OH-, SCN- CN- • Bidentate – 2 lone pair electron donor –1,2 diaminoethane H2NCH2CH2NH2, ethanedioate (C2O4)2- •Polydentate – 6 lone pair electron donor – EDTA4- (ethylenediaminetetraacetic acid) Complex ion with diff metal ion, ligand, oxidation state and overall charge Mn+L: :L Mn+ :L :L L: L: Mn+ :L :L :L :L Mn+ :L :L :L :L :L :L Coordination number – number of ligand around central ion 2 4 4 6
- 12. Ligand • Neutral/anion species that donate lone pair/non bonding electron pair to metal ion • Lewis base, lone pair donor – dative bond with metal ion Neutral ligand Anion ligand H2O NH3 CO CI– CN– O2- OH– SCN– : CI : :. Monodentate Bidentate Polydentate C2O4 2- C2H4(NH2)2 Ligand displacement Co/CN > en > NH3 > SCN- > H2O > C2O4 2- > OH- > F- > CI- > Br- > I- Spectrochemical series Tetraaqua copper(II) ion H2O displace by CI- 2+ CI- displace by NH3 Tetrachloro copper(II) ion Stronger ligand displace weaker ligand Tetraamine copper(II) ion О О Stronger ligand Stronger ligand Chelating agent EDTA – for removal of Ca2+ • Prevent blood clotting • Detoxify by removing heavy metal poisoning
- 13. 4s 3d Magnetic properties of transition metals Paired electron – spin cancel – NO net magnetic effect Ti V Cr Mn Fe Co Diamagnetism ↓ Paired electron ↓ No Net magnetic effect (Repel by magnetic field) Ni Zn Spin cancel Sc Spinning electron in atom – behave like tiny magnet Unpaired electron – net spin – Magnetic effect Spin cancel Net spin Paramagnetism ↓ Unpaired electron ↓ Net magnetic effect (Attract by magnetic field) Material Diamagnetic Paramagnetic Ferromagnetic • Iron • Cobalt • Nickel Zn2+ Mn2+ Click here paramagnetism Click here paramagnetism Click here levitation bismuth Click here levitation
- 14. 4s 3d Magnetic properties of transition metals Ti V Cr Mn Fe Co Diamagnetism ↓ Paired electron ↓ No Net magnetic effect (Repel by magnetic field) Zn Spin cancel Net spin Sc pyrolytic graphite Spin cancel Spin cancel Paramagnetism ↓ Unpaired electron ↓ Net magnetic effect (Attract by magnetic field) DiamagneticParamagnetic Click here levitation bismuth Click here levitation Click here paramagnetism measurement Vs Bismuth Click here paramagnetism Strong diamagnetic materials
- 15. Pt/Pd surface Transition Metal – Catalytic Activity Catalytic Properties of Transition metal • Variable oxidation state - lose and gain electron easily. • Use 3d and 4s electrons to form weak bond. • Act as Homogeneous or Heterogenous catalyst – lower activation energy • Homogeneous catalyst – catalyst and reactant in same phase/state • Heterogeneous catalyst – catalyst and reactant in diff phase/state • Heterogenous catalyst- Metal surface provide active site (lower Ea ) • Surface catalyst bring molecule together (close contact) -bond breaking/making easier Transition metal as catalyst with diff oxidation states 2H2O2 + Fe2+ → 2H2O+O2+Fe3+ H2O2+Fe2+→H2O + O2 + Fe3+ Fe3+ + I - → Fe2+ + I2 Fe2+ ↔ Fe3+ Rxn slow if only I- is added H2O2 + I- → I2 + H2O + O2 Rxn speed up if Fe2+/Fe3+ added Fe2+ change to Fe3+ and is change back to Fe2+ again recycle molecule adsorp on surface catalyst Pt/Pd surface Bond break Bond making 3+ CH2 = CH2 + H2 → CH3 - CH3 Nickel catalyst Without catalyst, Ea CH2= CH2 + H2 CH3 - CH3 Surface of catalyst for adsorption With catalyst, Ea adsorption H2 adsorption C2H4 bond breaking making desorption C2H6 Fe2+ catalyst How catalyst work ? Activation energy
- 16. • Haber Process – Production ammonia for fertiliser/ agriculture 3H2 + N2 → 2NH3 Uses of transition metal as catalyst in industrial process Iron , Fe Vanadium (V) oxide, V2O5 Nickel, Ni Manganese (IV) oxide, MnO2 Platinum/Palladium, Pt/PdCobalt, Co3+ Iron , Fe2+ ion Contact Process – Sulphuric acid/batteries 2SO2 + O2 → 2SO3 Hydrogenation Process- Margerine and trans fat C2H4 + H2 → C2H6 Hydrogen peroxide decomposition – O2 production 2H2O2→ 2H2O + O2 Catalytic converter – Convertion to CO2 and N2 2CO + 2NO → 2CO2 + N2 Biological enzyme Hemoglobin – transport oxygen Vitamin B12 – RBC production NH3 Co3+ O2Fe2+
- 17. Why transition metals ion complexes have diff colour? Transition Metal – Colour Complexes Colour you see is BLUE – Blue reflected/transmitted to your eyes - Red/orange absorbed (complementary colour) Colour you see is Yellow – Yellow reflected/transmitted to your eyes - Violet absorbed (complementary colour) complementary colour Blue transmitted Wave length - absorbed Wave length - absorbed Visible light Visible light Yellow transmitted absorbed
- 18. Formation coloured complexes Variable Colours Click here vanadium ion complexes Click here nickel ion complexes V5+/ VO2 + - yellow V4+/ VO2+ - blue V3+ - green V2+ - violet NiCI2 - Yellow NiSO4 - Green Ni(NO3)2 - Violet NiS - Black Diff oxidation states Colour formation Nature of transition metal Oxidation state Diff ligands Shape Stereochemistry Diff ligandsDiff metals MnCI2 - Pink MnSO4 - Red MnO2 - Black MnO4 - - Purple Cr2O3 - Green CrO4 2- - Yellow CrO3 - Red Cr2O7 2- - Orange Shape/ Stereochemistry Tetrahedral Octahedral BlueYellow Transition Metal – Colour Complexes Ion Electron configuration Colour Sc3+ [Ar] colourless Ti3+ [Ar]3d1 Violet V3+ [Ar]3d2 Green Cr3+ [Ar]3d3 Violet Mn2+ [Ar]3d5 Pink Fe2+ [Ar]3d6 Green Co2+ [Ar]3d7 Pink Ni2+ [Ar]3d8 Green Cu2+ [Ar]3d9 Blue Zn2+ [Ar]3d10 colourless
- 19. Ion configuration Colour Ti3+ [Ar] 3d1 Violet V3+ [Ar] 3d2 Green Cr3+ [Ar] 3d3 Violet Mn2+ [Ar] 3d5 Pink Fe2+ [Ar] 3d6 Green Co2+ [Ar] 3d7 Pink NO ligand • Degenerate • 3d orbital same energy level • five 3d orbital equal in energy Five 3d orbital (Degenerate – same energy level) Transition Metal – Colour Complexes Presence of ligand • 3d orbital split • five 3d orbital unequal in energy Mn2+ [Ar]3d5 3d yz3d xy 3d xz 3d Z 23dx 2 - y 2 ∆E lies between axes lies along axes Mn2+ :L:L :L Colour- Splitting 3d orbital by ligand :L:L :L :L :L :L :L :L :L 3d xy 3d xz 3d yz 3dx 2 - y 2 3d Z 2 No ligand – No repulsion – No splitting 3d orbitals Mn2+ No ligands approaching :L :L :L :L :L :L :L :L :L :L :L :L :L :L:L :L :L :L :L :L :L :L :L :L Ligands approaching Ligand approach not directly with 3d electron Less repulsion bet 3d with ligand Lower in energy Ligand approach directly 3d electron More repulsion bet 3d with ligand Higher in energy With ligand • Splitting of 3d orbital • 3d orbital unequal energy Elec/elec repulsion bet 3d e with ligand
- 20. Colour- Splitting of 3d orbital of metal ion by ligand NO ligand • Degenerate • 3d orbital same energy level • five 3d orbital equal in energy Five 3d orbital (Degenerate – same energy level) Splitting 3d orbital Electronic transition possible Photon light absorb to excite elec With ligand • Splitting of 3d orbital • 3d orbitals unequal energy Why Ti 3+ ion solution is violet ? violet Transition Metal – Colour Complexes Presence of ligand • 3d orbital split • five 3d orbital unequal in energy Ti3+ [Ar] 3d1 3d yz3d xy 3d xz 3d Z 23d x 2 - y 2 Ti3+ [Ar] 3d1 ∆E Ion configuration Colour Sc3+ [Ar] colourless Ti3+ [Ar] 3d1 Violet V3+ [Ar] 3d2 Green Cr3+ [Ar] 3d3 Violet Mn2+ [Ar] 3d5 Pink Fe2+ [Ar] 3d6 Green Co2+ [Ar] 3d7 Pink Ni2+ [Ar] 3d8 Green Cu2+ [Ar] 3d9 Blue Zn2+ [Ar] 3d10 colourless Green / yellow wavelength - Abosrb to excite electron О
- 21. Colour- Splitting of 3d orbital of metal ion by ligand NO ligand • Degenerate • 3d orbital same energy level • five 3d orbital equal in energy Five 3d orbital (Degenerate – same energy level) Splitting 3d orbital Electronic transition possible Photon light absorb to excite elec With ligand • Splitting of 3d orbital • 3d orbitals unequal energy Why Cu3+ ion solution is blue ? Blue Transition Metal – Colour Complexes Presence of ligand • 3d orbital split • five 3d orbital unequal in energy Cu2+ [Ar] 3d9 3d yz3d xy 3d xz 3d Z 23d x 2 - y 2 Cu2+ [Ar] 3d9 ∆E Ion configuration Colour Sc3+ [Ar] colourless Ti3+ [Ar] 3d1 Violet V3+ [Ar] 3d2 Green Cr3+ [Ar] 3d3 Violet Mn2+ [Ar] 3d5 Pink Fe2+ [Ar] 3d6 Green Co2+ [Ar] 3d7 Pink Ni2+ [Ar] 3d8 Green Cu2+ [Ar] 3d9 Blue Zn2+ [Ar] 3d10 colourless Red / orange wavelength - Abosrb to excite electron О Cu2+
- 22. Colour- Splitting of 3d orbital of metal ion by ligand NO ligand • Degenerate • 3d orbital same energy level • five 3d orbital equal in energy Five 3d orbital (Degenerate – same energy level) Splitting 3d orbital NO electron NO absorption light NO electronic transition possible With ligand • Splitting of 3d orbital • 3d orbital unequal energy Why Sc 3+ ion solution is colourless ? Colourless Transition Metal – Colour Complexes Presence of ligand • 3d orbital split • five 3d orbital unequal in energy Sc3+ [Ar] 3d0 3d yz3d xy 3d xz 3d Z 23d x 2 - y 2 Sc3+ [Ar] 3d0 ∆E Ion configuration Colour Sc3+ [Ar] colourless Ti3+ [Ar] 3d1 Violet V3+ [Ar] 3d2 Green Cr3+ [Ar] 3d3 Violet Mn2+ [Ar] 3d5 Pink Fe2+ [Ar] 3d6 Green Co2+ [Ar] 3d7 Pink Ni2+ [Ar] 3d8 Green Cu2+ [Ar] 3d9 Blue Zn2+ [Ar] 3d10 colourless All wavelength transmitted Sc3+ NO absorption white
- 23. Colour- Splitting of 3d orbital of metal ion by ligand NO ligand • Degenerate • 3d orbital same energy level • five 3d orbital equal in energy Five 3d orbital (Degenerate – same energy level) With ligand • Splitting of 3d orbital • 3d orbital unequal energy Why Zn 3+ ion solution is colourless ? Colourless Transition Metal – Colour Complexes Presence of ligand • 3d orbital split • five 3d orbital unequal in energy Zn2+ [Ar] 3d10 3d yz3d xy 3d xz 3d Z 23d x 2 - y 2 Zn2+ [Ar] 3d10 ∆E Ion configuration Colour Sc3+ [Ar] colourless Ti3+ [Ar] 3d1 Violet V3+ [Ar] 3d2 Green Cr3+ [Ar] 3d3 Violet Mn2+ [Ar] 3d5 Pink Fe2+ [Ar] 3d6 Green Co2+ [Ar] 3d7 Pink Ni2+ [Ar] 3d8 Green Cu2+ [Ar] 3d9 Blue Zn2+ [Ar] 3d10 colourless Zn2+ All wavelength transmittedSplitting 3d orbital FULLY FILLED NO absorption light NO electronic transition possible NO absorption white
- 24. Colour- Splitting of 3d orbital of metal ion by ligand NO ligand • Degenerate • 3d orbital same energy level • five 3d orbital equal in energy Five 3d orbital (Degenerate – same energy level) With ligand • Splitting of 3d orbital • 3d orbital unequal energy Why Cu3+ ion solution is colourless ? Colourless Transition Metal – Colour Complexes Presence of ligand • 3d orbital split • five 3d orbital unequal in energy Cu+ [Ar] 3d10 3d yz3d xy 3d xz 3d Z 23d x 2 - y 2 Cu+ [Ar] 3d10 ∆E Zn2+ All wavelength transmittedSplitting 3d orbital FULLY FILLED NO absorption light NO electronic transition possible Ion configuration Colour Sc3+ [Ar] colourless Ti3+ [Ar] 3d1 Violet V3+ [Ar] 3d2 Green Cr3+ [Ar] 3d3 Violet Mn2+ [Ar] 3d5 Pink Cu+ [Ar] 3d10 Colourless Cu2+ [Ar] 3d9 Blue white NO absorption
- 25. Colour- Splitting of 3d orbital of metal ion by ligand NO ligand • Degenerate • 3d orbital same energy level • five 3d orbital equal in energy Five 3d orbital (Degenerate – same energy level) No ligand/Water • NO Splitting 3d orbital • 3d orbital equal energy Why Cu3+ ion anhydrous is colourless ? Transition Metal – Colour Complexes NO ligand • 3d orbital split • five 3d orbital equal in energy Cu2+ [Ar] 3d9 3d yz3d xy 3d xz 3d Z 23d x 2 - y 2 Cu2+ [Ar] 3d9 Ion configuration Colour Sc3+ [Ar] colourless Ti3+ [Ar] 3d1 Violet V3+ [Ar] 3d2 Green Cr3+ [Ar] 3d3 Violet Mn2+ [Ar] 3d5 Pink Fe2+ [Ar] 3d6 Green Co2+ [Ar] 3d7 Pink Ni2+ [Ar] 3d8 Green Cu2+ [Ar] 3d9 Blue Cu2+ Colourless NO Splitting 3d orbital NO absorption light NO electronic transition possible All wavelength transmit white NO absorption
- 26. Formation coloured complexes V5+/ VO2 + - yellow V4+/ VO2+ - blue V3+ - green V2+ - violet NiCI2 - Yellow NiSO4 - Green Ni(NO3)2 - Violet NiS - Black Diff oxidation states Colour formation Nature of transition metal Diff ligands Diff metals MnCI2 - Pink MnSO4 - Red MnO2 - Black MnO4 - - Purple Cr2O3 - Green CrO4 2- - Yellow CrO3 - Red Cr2O7 2- - Orange Shape/ Stereochemistry Tetrahedral Octahedral BlueYellow Transition Metal – Colour Complexes Ion configuration Colour Ti3+ [Ar]3d1 Violet V3+ [Ar]3d2 Green Cr3+ [Ar]3d3 Violet Mn2+ [Ar]3d5 Pink Fe2+ [Ar]3d6 Green Co2+ [Ar]3d7 Pink Ni2+ [Ar]3d8 Green Cu2+ [Ar]3d9 Blue Colour- Splitting 3d orbital by ligand Strong ligand (higher charge density) ↓ Greater splitting ↓ Diff colour Weak ligand (Low charge density) ↓ Smaller splitting ↓ Diff colour No ligand ↓ No splitting ↓ No colour Spectrochemical series – Strong ligand → Weak Ligand Co/CN > en > NH3 > SCN- > H2O > C2O4 2- > OH- > F- > CI- > Br- > I- NO ligand – NO splitting 3d orbital (Same energy level) WEAK ligand – small splitting 3d orbital (Unequal energy) ∆E ∆E STRONG ligand – greater splitting 3d orbital (Unequal energy)
- 27. I- < Br- < CI- < F- < OH- < C2O4 2- < H2O < SCN- < NH3 < en < Co/CN Transition Metal – Colour Complexes Colour- Splitting 3d orbital by ligand Strong ligand (higher charge density) ↓ Greater splitting - ↑∆E Diff colour Weak ligand (Low charge density) ↓ Smaller splitting - ↓∆ E Diff colour No ligand ↓ No splitting No colour Spectrochemical series – Weak ligand → Strong Ligand NO ligand – NO splitting 3d orbital (Same energy level) WEAK ligand – small splitting 3d orbital (Unequal energy) ∆E ∆E STRONG ligand – greater splitting 3d orbital (Unequal energy) Very Strong ligand ↓ Greater splitting - ↑∆E Diff colour ∆E Ion ES Colour Cu(CI4)2- 3d9 Colourless Cu(CI4)2- 3d9 Green Cu(H2O)6 2+ 3d9 Blue Cu(NH3)4 2+ 3d9 Violet Cu2+ [Ar] 3d9 Cu2+ STRONGEST ligand – greatest splitting О О О Ligand I- Br- CI- F- C2O4 2- H2O SCN- NH3 en Co/CN- ʎ (wave length) longest shortest ∆E Weak field Smallest Split Strong field Highest Split [Cu(CI)4]2- [Cu(NH3)4]2+[Cu(H2O)6]2+ О О О
- 28. H2O stronger ligand ↓ Greater spitting ∆E ↓ Higher energy wavelength absorbed CI- weak ligand ↓ Small spitting ∆E ↓ Low energy wavelength absorbed NH3 strongest ligand ↓ Greatest spitting ∆E ↓ Highest energy wavelength absorbed - Higher energy absorbed - Orange wavelength absorb to excite electron - Highest energy absorbed - Yellow wavelength absorb to excite electron Transition Metal – Colour Complexes Colour- Splitting 3d orbital by ligand Strong ligand (higher charge density) ↓ Greater splitting - ↑∆E - Diff colour Weak ligand (Low charge density) ↓ Smaller splitting - ↓∆ E - Diff colour Spectrochemical series – Weak ligand → Strong Ligand WEAK ligand – small splitting 3d orbital (Unequal energy) ∆E ∆E STRONG ligand – greater splitting 3d orbital (Unequal energy) Very Strong ligand ↓ Greater splitting - ↑∆E- Diff colour ∆E Cu(H2O)6 2+ 3d9 Blue STRONGEST ligand – greatest splitting [Cu(NH3)4]2+[Cu(H2O)6]2+ - Lower energy absorbed - Red wavelength absorb to excite electron [Cu(CI)4]2- Cu(CI4)2- 3d9 Green Cu(NH3)4 2+ 3d9 Violet
- 29. Nuclear charge - +5 ↓ Strong ESF atrraction bet –ve ligand ↓ Greatest splitting ∆E ↓ Highest energy wavelength absorb Nuclear charge - +3 ↓ Strong ESF atrraction bet –ve ligand ↓ Greater splitting ∆E ↓ Higher energy wavelength absorb Mn(H2O)6 2+ +2 PINK Nuclear charge - +2 ↓ Weak ESF atrraction bet –ve ligand ↓ Smaller splitting ∆E ↓ Low energy wavelength absorb - Higher energy absorbed - Blue wavelength absorb to excite electron - Highest energy absorbed - Violet wavelength absorb to excite electron Transition Metal – Colour Complexes Colour- Splitting 3d orbital by ligand High nuclear charge / charge density ↓ Greater splitting - ↑∆E - Diff colour Low nuclear charge /charge density ↓ Smaller splitting - ↓∆ E - Diff colour Nuclear charge on metal ion Low nuclear charge – small splitting 3d orbital (Unequal energy) ∆E ∆E High nuclear charge – greater splitting 3d orbital (Unequal energy) Highest nuclear charge/charge density ↓ Greatest splitting - ↑∆E- Diff colour ∆E Fe(H2O)6 3+ +3 YELLOW HIGHEST nuclear charge – greatest splitting Fe(H2O)6 3+ - Lower energy absorbed - Green wavelength absorb to excite electron V(H2O)6 5+ +5 YELLOW/GREEN Mn(H2O)6 2+ V(H2O)6 5+
- 30. Oxidation number - +3 ↓ Strong ESF atrraction bet –ve ligand ↓ Greater splitting ∆E ↓ Higher energy wavelength absorb Oxidation number - +2 ↓ Weak ESF atrraction bet –ve ligand ↓ Smaller splitting ∆E ↓ Low energy wavelength absorb Transition Metal – Colour Complexes Colour- Splitting 3d orbital by ligand Higher oxidation number/charge density ↓ Greater splitting - ↑∆E - Diff colour Lower ESF attraction – small splitting 3d orbital (Unequal energy) ∆E ∆E STRONG ligand – greater splitting 3d orbital (Unequal energy) ∆E Fe(H2O)6 3+ +3 Yellow - Lower energy absorbed - Red wavelength absorb to excite electron Fe(H2O)6 2+ +2 Green Oxidation number on metal ion Low oxidation number /charge density ↓ Smaller splitting - ↓∆ E - Diff colour Fe(H2O)6 2+ - Higher energy absorbed - Blue wavelength absorb to excite electron Fe(H2O)6 3+ V(H2O)6 5+ +5 YELLOW/GREEN Highest oxidation number/charge density ↓ Greatest splitting - ↑∆E- Diff colour HIGHEST nuclear charge – greatest splitting - Highest energy absorbed - Violet wavelength absorbed to excite electron Nuclear charge - +5 ↓ Strongest ESF atrraction bet –ve ligand ↓ Greatest splitting ∆E ↓ Highest energy wavelength absorb V(H2O)6 5+
- 31. ∆E :L:L :L :L:L :L :L :L Cu2+ Ligand tetrahedrally :L :L :L :L :L :L :L :L :L :L :L :L :L :L:L :L :L :L :L :L :L :L :L :L Ligand octahedrally Ligand approach not directly with 3d elec Less repulsion bet 3d with ligand Lower in energy Ligand approach directly 3d elec More repulsion bet 3d with ligand Higher in energy Greater Splitting Elec/elec repulsion bet 3d elec with ligand Transition Metal – Colour Complexes Colour- Splitting 3d orbital by ligand Shape of complex ion Complex ion – Octahedral- Cu(H2O)6 2+ Cu(H2O)6 2+ 3d9 BlueCu(H2O)4 2+ 3d9 Green Complex ion – Tetrahedral- Cu(H2O)4 2+ Cu2+ More ligands – more repulsion ↓ Greater splitting - ↑∆E - Diff colour Less ligands – less repulsion ↓ Smaller splitting - ↓∆E - Diff colour :L :L :L :L :L :L:L :L :L :L:L :L :L :L:L :L :L :L :L :L :L :L :L :L :L :L :L :L Elec/elec repulsion bet 3d elec with ligand Ligand approach directly 3d elec More repulsion bet 3d with ligand Higher in energy ∆E Ligand indirectly with 3d elec Less repulsion Lower in energy Smaller Splitting Tetrahedrally Octahedrally
- 32. Acknowledgements Thanks to source of pictures and video used in this presentation http://crescentok.com/staff/jaskew/isr/tigerchem/econfig/electron4.htm http://pureinfotech.com/wp-content/uploads/2012/09/periodicTable_20120926101018.png Thanks to Creative Commons for excellent contribution on licenses http://creativecommons.org/licenses/ Prepared by Lawrence Kok Check out more video tutorials from my site and hope you enjoy this tutorial http://lawrencekok.blogspot.com