Transition Metal Chemistry

4p

3d

4s

d orbital splittingin a typical transitionmetal atom

Sc 4s2d1

Ti 4s2d2

V 4s2d3

Cr 4s1d5

Mn 4s2d5

Fe 4s2d6

Co 4s2d7

Ni 4s2d8

Cu 4s1d10

Zn 4s2d10

4p

3d

4s

d orbital splittingin a typical transitionmetal atom

The 4s an 4p orbitals is much more diffusein space than are the 3d orbitals. They havea higher quantum number n and the havefewer nodes (0 or 1) versus 2 for the d orbitals.

This means that when a transition metalatom bonds to other atoms, the most significant interactions are with the s andp orbitals, not the d orbitals.

4p

4s

3d

4p

4s

3d

4p

3d

4s

The 3d orbitals are not as important forbonding as are the 4s and 4p, but the details of what happens tothe 3d orbitals determine the propertiesof transition metal complexes.

3d

Coordination Compounds

Co(NH3)6+3

NH3

Base - electron pair donorLigand

Co(en)3+3

NNH

H

H

H

Ethylenediamine1,2-diaminoethane Chelate

Bidentate Ligand

Common LigandsNH3 ammineH2O aquaOH- hydroxoCN- cyanoCO carbonylNO2

- nitroF- fluoroCl- chloroBr- bromoI- iodo

Square Planar Complexes

trans

cis

OctahedralComplexes

cis

trans

facial meridial

Tetrahedral complexes

Optical Isomerism

Porphyrin

N

N

N

NH

H

Protoporphyrin IX