Cisplatin and Chemical Software

Although some students of organic chemistry may be accustomed to interpreting a tetracoordinate atom as a flattened tetrahedron, cisplatin has a square planar geometry. This shape minimizes repulsive interactions between electrons in the d orbitals. There is a difference between cis and trans forms of a complex with two sets of identical ligands about a central, planar atom. Therefore, cisplatin provides a useful shibboleth when examining a chemical information software package. Most such packages recognize stereochemistry about tetrahedral carbon, but few can discriminate between the cis and trans isomers of planar diamminedichloroplatinum(II).
Try an exact-match search on cisplatin using your software and see if you also hit the trans isomer!

graphic of cis- and trans-DDP

Please see the reference frame for a list of suggestions on learning more about the factors that affect the geometry of metal complexes.