1. Coordination Chemistry ligands bonding to metals

2. Donor-Acceptor Complexes

3. Definitions Lewis Acid = acceptor = usually a transition metal cation Lewis Base = donor = ligand = usually something with a lone electron pair Coordination number = # of metal-ligand attachments Denticity = # of attachments a ligand makes

4. Common Ligands Monodentate Ligands: Halides: F -, Cl -, Br -, I - O 2-, S 2-, OH -, CN - NH 3, H 2 O, CO Bidentate Ligands:Polydentate Ligands: heme, salen

5. Monodentate complexes

7. Bidentate ligand complexes Ni(DMG) 2 Co(en) 2 Cl 2

8. Bidentate complexes Co(en) 3 2+ Fe(phen) 3 2+

9. Polydentate complexes Co(salen) + chlorophyll

10. Fe-heme

11. Polydentate complexes Fe-heme O 2 -Fe-heme

12. Determining Metal Oxidation States [Ag(NH 3 ) 2 ]NO 3 K 2 [NiCl 4 ] [Co(en) 2 Cl 2 ]Cl [Cr(H 2 O) 4 CO 3 ]Br

13. Isomerization in Coordination Compounds Do for octahedral Complexes

14. Inner and Outer Spheres [Co(NH 3 ) 4 Cl 2 ]Cl  H 2 O [Co(NH 3 ) 4 (H 2 O)Cl]Cl 2

15. All compounds Structural (constitutional) Stereo linkage ionization hydration geometric optical [Co(NH 3 ) 5 Cl]NO 2 [Co(NH 3 ) 5 NO 2 ]Cl [Co(NH 3 ) 4 Cl(H 2 O)]Cl 2 [Co(NH 3 ) 4 Cl 2 ]Cl  H 2 O [Co(NH 3 ) 5 SCN] 2+ [Co(NH 3 ) 5 NCS] 2+

16. Linkage Isomers

17. Ionization Isomers

18. Hydration Isomers

19. Optical Isomers: enantiomers (mirror images) key to recognizing: no mirror planes of symmetry Type 1. arrangement of monodentate ligands Type 2. arrangement of bidentate ligands

20. Geometric isomerism: like cis-trans

21. Geometric isomerism Fac- isomer Mer- isomer

22. Geometric Isomers: predicting numbers Use shorthand: M = metal a, b, c, etc. are different ligands Example 1: Co(NH 3 ) 4 Cl 2

23. Example 2: Co(NH 3 ) 3 BrCl 2

24. Example 3: Co(NH 3 ) 3 enBr 2+