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 (from the metal’s point of view)
Denticity = # of attachments a ligand makes (from the ligand’s point of view)

4. Common Ligands Monodentate Ligands: Halides: F-, Cl-, Br-, I-
O2-, S2-, OH-, CN-
NH3, H2O, CO
Bidentate Ligands:
Polydentate Ligands:
heme, salen

5. Monodentate complexes

6. Monodentate complexes

7. Bidentate ligand complexes
Co(en)2Cl2
Ni(DMG)2

8. Bidentate complexes
Co(en)32+
Fe(phen)32+

9. Polydentate complexes
Co(salen)+
chlorophyll

10. Fe-heme

11. Polydentate complexes
Fe-heme
O2-Fe-heme

12. Free Times
M 12:30 – 3
T 10 – 1:30
W 11 – 2
Th 12 – 2

13. Determining Metal Oxidation States
[Ag(NH3)2]NO3
K2[NiCl4]
[Co(en)2Cl2]Cl
[Cr(H2O)4CO3]Br

14. Chelate Effect
Cd(CH3NH2)42+ vs. Cd(en)22+
Thermodynamics of Formation
Ligands Ho (kJ/mol) So (J/K-mol) TSo (J/mol) Go (kJ/mol)
4 CH3NH
2 en
Another example:
[Ni(NH3)6] en  [Ni(en)3] NH K =

15. Isomerization in Coordination Compounds
Do for octahedral Complexes

16. Inner and Outer Spheres
[Co(NH3)4Cl2]Cl H2O
[Co(NH3)4(H2O)Cl]Cl2

17. All compounds
Structural (constitutional)
Stereo
linkage ionization hydration geometric optical
[Co(NH3)5Cl]NO2
[Co(NH3)5NO2]Cl
[Co(NH3)4Cl(H2O)]Cl2
[Co(NH3)4Cl2]ClH2O
[Co(NH3)5SCN]2+
[Co(NH3)5NCS]2+

18. Linkage Isomers

19. Ionization Isomers

20. Hydration Isomers

21. 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

22. Geometric isomerism: like cis-trans

23. Geometric isomerism
Fac- isomer
Mer- isomer

24. Example 1: Co(NH3)4Cl2 Geometric Isomers: predicting numbers
Use shorthand:
M = metal
a, b, c, etc. are different ligands
Example 1: Co(NH3)4Cl2

25. Example 2: Co(NH3)3BrCl2

26. Example 3: Co(NH3)3enBr2+

27. Example 3: Co(NH3)3enBr2+

28. Example 3: Co(NH3)3enBr2+

29. Example 3: Co(NH3)3enBr2+

30. Example 3: Co(NH3)3enBr2+

31. Example 3: Co(NH3)3enBr2+