Coordination Number 2

The linear [Ag(NH3)2]+ ion

Although [Ag(en)]ClO4 involves a normally bidentate ligand, in this case the structure is polymeric and the silver ion still retains a CN=2 with the N atoms (from different ligands) at ~180 degrees to each other.

Coordination Number 3

Trigonal planar - D3h

[Cu(CN)3]2-

[CuBr(PNP)] where PNP= (2,6-bis[(di-tert-butylphosphino)methyl]pyridine)

To help view more easily, the H atoms are turned off.

Trigonal pyramid

T-shaped

[Cu(PNP)]SbF6 where PNP= (2,6-bis[(di-tert-butylphosphino)methyl]pyridine)

To help view more easily, the H atoms are turned off.

Coordination Number 4

Tetrahedral

CoCl2pyr2

Square Planar

cisplatin - cis-PtCl2(NH3)2

The cis- isomer is a powerful anti-cancer drug whereas the trans- is inactive.

Coordination Number 5

Square pyramid

Trigonal Bipyramid

[Ni(CN)5]3-

Coordination Number 6

Hexagonal planar

Trigonal prism

tris(cis-1,2-diphenylethene-1,2-dithiolato)rhenium

The ReS6 geometry is perfectly trigonal prismatic.

Octahedral

Hexol

The first 'truly' inorganic complex to be resolved into its optical isomers.

[Co(en)3]Cl3

mirror images

The classic example of optical isomerism in octahedral coordination complexes (H atoms not shown).
D isomer
L isomer

[CoCO3(NH3)5]+


Coordination Number 7

Capped octahedron (C3v)

K3[NbOF6]

Capped trigonal prism (C2v)

[V(III)(Hedta)(H2O)]H2O

Pentagonal Bipyramid (D5h)

bis-(tert-butylacac)2(DMSO)di-oxoUranium

The UO7 geometry fits a pentagonal bipyramid.

Coordination Number 8

Dodecahedron (D2d)

[Zr(acac)2(NO3)2]


[Zr(C2O4)4]4- is reported to have this shape as well.

Cube (Oh)

Square antiprism (D4d)

U(acac)4

Hexagonal bipyramid (D6h)

UO2(OAc)3

Coordination Number 9

Three-face centred trigonal prism (D3h)

Hydrated salts of the lanthanide elements eg Eu(H2O)9]3+

Coordination Number 10

Bicapped square antiprism (D4d)

Tetrakis(nitrato-O,O')-bis(triphenylphosphine oxide) cerium(IV)


Another example is [Ce(NO3)5]2-

Coordination Number 11

All-faced capped trigonal prism (D3h)

This is not a common stereochemistry.
In aqua-(12-crown-4)-tris(nitrato-O,O')-cerium(III) (12-crown-4) solvate and (15-crown-5)-tris(nitrato-O,O')-cerium(III) the Cerium ion is 11 coordinate.

Coordination Number 12

cuboctahedron (Oh)

Ceric ammonium nitrate -(NH4)2Ce(NO3)6


Return to Chemistry, UWI-Mona, Home Page

Copyright © 1996-2014 by Robert John Lancashire, all rights reserved.

Created and maintained by Prof. Robert J. Lancashire,
The Department of Chemistry, University of the West Indies,
Mona Campus, Kingston 7, Jamaica.
Created March 1996. Links checked and/or last modified 15th January 2014.
URL http://wwwchem.uwimona.edu.jm/courses/IC10Kcnpics.html