1. Transition metals Produce compounds with at least one stable oxidation state with a partially filled d-orbital Zn (4s 2 3d 10 )  Zn 2+ (3d 10 ) NOT TM Cu (4s 1 3d 10 )  Cu 2+ (3d 9 ) TM Transition metals: electron shells Compounds are often coloured – absorption spectra by electrons transitioning between split d-orbital d-orbitals split by ligands. Full/empty d orbital: no transition possible so no colour absorbed Different ligands  different colours Multiple oxidation states: Ions form by losing d- electrons  little change in radius  extra ionisation energy ≈ extra lattice energy

2. Vanadium +5 VO 2 + +4 VO 2+ +3 V 3+ [V(H 2 O) 6 ] 3+ +2 V 2+ [V(H 2 O) 6 ] 2+ Note: oxo-ions for high oxidation states

3. Conversion between vanadium oxidation states 2VO 2 + (aq) + 4H + (aq) + 2e –  2VO 2+ (aq) + 2H 2 O (l) SO 3 2 – (aq) + H 2 O (l)  SO 4 2 – (aq) + 2H + (aq) + 2e – (aq) 2VO 2 + (aq) + SO 3 2 – (aq) + 2H + (aq)  2VO 2+ (aq) + SO 4 2 – (aq) + H 2 O (l) 2VO 2 + (aq) + 4H + (aq) + 2e –  2VO 2+ (aq) + 2H 2 O (l) Zn(s)  Zn 2+ (aq) + 2e – 2VO 2 + (aq) + 4H + (aq) + Zn(s)  2VO 2+ (aq) + Zn 2+ (aq) + 2H 2 O (l) 2VO 2+ + 2e – + 4H + (aq)  2V 3+ (aq) + 2H 2 O (l) Zn(s)  Zn 2+ (aq) + 2e – 2VO 2+ + Zn(s) + 4H + (aq)  2V 3+ (aq) + Zn 2+ (aq) + 2H 2 O (l) 2V 3+ (aq) + 2e –  2V 2+ (aq) Zn(s)  Zn 2+ (aq) + 2e – 2V 3+ (aq) + Zn(s)  2V 2+ (aq) + Zn 2+ (aq)

4. Deprotonation and ligand exchange Deprotonation [Cu(H 2 O) 6 ] 2+ (aq) + 2 OH -  Cu(OH) 2 (H 2 O) 4 (s) + 2 H 2 O A H + ion is removed from the hydrating water Ligand exchange Cu(OH) 2 (H 2 O) 4 (s) + 4 NH 3  [Cu(NH 3 ) 4 (H 2 O) 2 ] 2+ (aq) + 2 H 2 O + 2 OH - The NH 3 swaps places with the ligands

5. Identification of metal ions Flame tests – see AS! + OH - : drops followed by excess (DEPROTONATION) Cu 2+ - pale blue ppt; remains Fe 2+ - dirty green ppt; remains (slowly oxidises) Fe 3+ - foxy brown ppt; remains Ni 2+ - green ppt; remains Mn 2+ - beige ppt; remains Cr 3+ - green ppt; soluble Zn 2+ - white ppt; dissolves

6. Identification of metal ions + NH 3 : drops followed by excess (DEPROTONATION then LIGAND EXCHANGE) Cu 2+ - pale blue ppt; dissolves Fe 2+ - dirty green ppt; remains (slowly oxidises) Fe 3+ - foxy brown ppt; remains Ni 2+ - green ppt; dissolves Mn 2+ - beige ppt; remains Cr 3+ - green ppt; dissolves (?) Zn 2+ - white ppt; dissolves

7. Hydrated metal ions Cu O HH O HH O HH O HH O HH O HH Dative bond Covalent bond 2+2+ Hexaaquacopper (II) ion

8. Hydrated metal ions Cu O HH O HH O HH O HH Dative bond Covalent bond (s) O-H

9. Cu 2+2+ NH 3 H3NH3N H3NH3N O HH O HH Tetraamminediaquacopper (II) ion

10. Complex ions Cu 2+ - [Cu(H 2 O) 6 ] 2+ (aq); Cu(OH) 2 (s); [Cu(NH 3 ) 4 (H 2 O) 2 ] 2+ (aq) Fe 2+ - Fe(H 2 O) 6 ]2+ (aq) ; Fe(OH) 2 (s)  Fe(OH) 2 (s) Fe 3+ - Fe(H 2 O) 6 ]3+ (aq) ; Fe(OH) 3 (s) Ni 2+ - [Ni(H 2 O) 6 ] 2+(aq) ; Ni(OH) 2 (s); [Ni(NH 3 ) 6 ] 2+ (aq) Mn 2+ - [Mn(H 2 O) 6 ] 2+ (aq); Mn(OH) 2 (s) Cr 3+ - [Cr(H 2 O) 6 ] 3+ (aq); Cr(OH) 3 (s); [Cr(OH) 6 ] 3- (aq); [Cr(NH 3 ) 6 ] 3+ (aq) Zn 2+ - [Zn(H 2 O) 6 ] 2+ (aq); Zn(OH) 2 (s); [Zn(OH) 4 ] 2- (aq) [Zn(NH 3 ) 4 ] 2+ (aq) Transition metals: + OH -

11. Some other complex ions Tetrachlorocuprate (II) [CuCl 4 ] 2- Hexacyanoferrate (II) [Fe(CN) 6 ] 4- Hexacyanoferrate (III) [Fe(CN) 6 ] 3- Potassium hexacyanoferrate (III) K 3 [Fe(CN 6 )] Tetrachlorochromate (III) [CrCl 4 ] - Dichlorocuprate (I) [CuCl 2 ] - Diamminedichloroplatinum (II) Pt(NH 3 ) 2 Cl 2

12. Shapes of complex ions Similar to covalent molecules: –6 pairs of electrons: octahedral e.g. Cr(NH 3 ) 6 ] 3+ and [Cu(H 2 O) 6 ] 2+ –4 pairs of electrons: tetrahedral e.g.[CuCl 4 ] 2- and [CrCl 4 ] - –4 pairs of electrons: square planar e.g. Pt(NH 3 ) 2 Cl 2 2 pairs of electrons: linear e.g. [CuCl 2 ] - [Cl  Cu  Cl] -

13. Ligands Form complex ions by donating a pair of electrons L:  M Can be monodentate (e.g. H 2 O, NH 3, CN - or Cl - ) or polydentate (e.g. 1,2-diaminoethane H 2 NCH 2 CH 2 NH 2, EDTA or ethanedioate ion C 2 O 4 2- )