The present invention comprises a water-soluble square-planar cis-platinum(II) four-coordinate complex having the formula: EQU trans-R,R-DACH Pt(II) X.sub.2 or EQU trans-R,R-DACH Pt(II) Y wherein X is a monovalvent cation, two of which are present, selected from the group consisting of cyclopropanecarboxylato, shikimato, saccharatolactone, galacturonato and N,N-dimethyglycinato; wherein Y is a divalent cation selected from the group consisting of citraconato, 1,1-cyclobutanedicarboxylato, 1,1-cyclopropanedicarboxylato, isocitratolactone and Z-iminodiacetato where Z is bound to the nitrogen and is ethyl, propyl, Isopropyl, n-butyl, sec-butyl, ter-butyl, n-amyl, isoamyl or OH. In one preferred aspect the water-soluble square-planar cis-platinum(II) four-coordinate complex has the formula: EQU trans-R,R-DACH Pt(II) X.sub.2 wherein X is a monovalent cation. Two X substituents are present in the platinum complex. These X substituents are preferably selected from the group consisting of cyclopropanecarboxylato, shikimato, saccharatolactone, galacturonato and N,N-dimethylglycinato. Both X substituents are usually identical butmay be different.Board of Regents, University of Texas Syste
