ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Pentammine derivatives of platinum

I. I. Chernyaev, V. S. Orlová, L. A. Nazarová, and N. T. Kuznetsov

Academy of Sciences U.S.S.R., Moscow.

Abstract: The effect of NH₃ on trans-dihalo-, mixed dihalo-, and iodohydroxotetrammine-derivs. of Pt(IV) was studied. Only iodohydroxotetrammineplatinum(IV) salts (I) change into pure iodopentammineplatinum(IV) salts (II) which can be prepd. from NH₃ and the K salt of iodopentanitroplatinate(IV). II are changed easily into trans-dihalotetrammineplatinum(IV) salts (III) by the action of halogen acids. III contg. various halogens change with a simultaneous crystn. into mixed dihalotetrammineplatinum(IV) salts according to the equation: Pt[(NH₃)₄X₂](NO₃)₂ + Pt[(NH₃)₄Y₂](NO₃)₂ → 2Pt[(NH₃)₄XY](NO₃)₂. This reaction gives a good yield and is not reversible. Dihydroxotetrammineplatinum(IV) salts do not enter into the exchange reaction even with diiodotetrammineplatinum(IV) salts. AgNO₃ ppts. only 1 halide from the 2 which are in the inner co.ovrddot.ordination sphere of tetrammine derivs. and in the case of mixed dihalocomplexes the one with the lower atomic wt. is always pptd., indicating that I shows increased trans activity. Iodopentammineplatinum(IV) salts have properties similar to bromo- and chloropentammineplatinum(IV) salts. From pH values of solns. of nitrates of halo complexes, the trans activity of the ligands increases in the order OH < Cl < Br < I. The difficulties in the synthesis of II are caused by the increased trans activity of I. The existence of the cycle in halopentammineplatinum(IV) salts does not change their chem. properties. Nitropentammineplatinum(IV) salts can be prepd. by the action of dry NH₃ at 6 atm. pressure on solid dinitrotetrammineplatinum(IV) nitrate; in the former compd. NH₃ is unaffected and with HCl the chloropentammineplatinum(IV) salt is formed. The structure of trans-nitrosonitratoplatinum(IV) blue salt was proven partly by the reversible substitution of Cl for the nitrato group and partly by the prepn. of bromonitroso compds. The nitroso group in Pt(IV) complexes shows a high trans activity and is diamagnetic. By the action of dry NH₃ under pressure on nitronitratoplatinum(IV) salts hexammineplatinum(IV) salts are formed.

Full paper in Portable Document Format: 1311a646.pdf (in Russian)

Chemical Papers 13 (11) 646–655 (1959)