The increasing importance of complexes of platunum(II) owing to their potential use as antitumour drugs has aroused interest1. Coordination compounds formed by nitrogen donor ligands have been found to be significant in this context. Some of the importantcis-platinammine active antitumour drugs bind covalently to DNA under specific conditions, whereas the inactivetrans-compound does not. Spectral studies of dichloro (2, 2′-bipyridine) platinum(II)2,cis- andtrans-dichloro (dipyridine)platinum(II)3have been undertaken anticipating that these platinum(II) compounds in coordination with a base would provide additional evidence on the electronic configuration of such complexes.cis-Pt(py)2cl2has recently been found to be of biochemical importance and its antitumour and antimitogenic properties have been reported4–6. It is less toxic to mice and increases the survival time of mice affected by tumour. Pfeffer7has studied the i.r. and Raman spectra ofcis- andtrans-Pt(py)2cl2and coordinate bonding