A detailed account of these isomers are
given below This type of isomerism arises in heteroleptic
complexes due to different possible geometric
arrangements of the ligands Important examples
of this behaviour are found with coordination
numbers 4 and 6 In a square planar complex of
formula [MX2L2] (X and L are unidentate), the
two ligands X may be arranged adjacent to each
other in a cis isomer, or opposite to each other
in a trans isomer as depicted in Fig