Coordination Chemistry

ligands bonding to metals

Donor-Acceptor Complexes

DefinitionsLewis 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

Common LigandsMonodentate Ligands:

Halides: F-, Cl-, Br-, I-

O2-, S2-, OH-, CN-

NH3, H2O, CO

Bidentate Ligands: Polydentate Ligands:

heme, salen

Monodentate complexes

Monodentate complexes

Bidentate ligand complexes

Ni(DMG)2Co(en)2Cl2

Bidentate complexes

Co(en)32+

Fe(phen)32+

Polydentate complexes

Co(salen)+

chlorophyll

Polydentate complexes

Fe-hemeO2-Fe-heme

Geometric isomerism

Geometric isomerism

Fac- isomer Mer- isomer