Stable monomeric phosphaplatins, namely, (pyrophosphato)platinum(II) or platinum(IV) complexes containing a cis-cyclohexanediamine ligand or enantiomerically enriched or enantiopure trans-cyclohexanediamine ligands, and synthesis of these complexes, are provided. Efficacies and toxicities of the phosphaplatin compounds are determined toward a variety of cancers, including sensitive and resistant ovarian cancers, head and neck, and colon cancers. Compositions comprising the platinum complexes, and methods for treatment of proliferative diseases or disorders by means of the complexes or the compositions comprising them are disclosed.
