The synthesis and characterization of 1,1-bis(aminomethyl)cyclohexaneplatinum(II) compounds and the crystal structure determination of 1,1-bis(aminomethyl)-cyclohexaneaquosulphatoplatinum(II) monohydrate

The synthesis and characterization of a number of 1,1-bis(aminomethylcyclohexane)platinum(II) complexes is described. Reaction of 1,1-bis(aminomethyl- cyclohexane)dichloroplatinum(II) (LPtCl2) with silver sulphate and silver nitrate in water results in the isolation of the corresponding aquosulphato??monohydrate, LPt(H2O)SO4??H2O and dinitratoplatinum- (II), LPt(NO3)2, complexes. Treatment of aqueous solutions of these compounds with an equimolar amount of sodium hydroxide results in the formation of mixtures of hydroxo-bridged dimers and trimers. The less soluble cyclic trimeric species [LPt(??-OH)]3(NO3)3??2H2O and {[LPt(??-OH)]3}2(SO4)3???8H2O have been isolated. The 1H, 13C and 195Pt NMR spectra of the various compounds have been studied in D2O. In particular, 195Pt NMR is a valuable tool for identification of the various platinum complexes present in aqueous solution. IR spectral data are reported. The IR spectra of LPt(SO4)???xH2O containing varying amounts of water of crystallization and/or coordination are discussed. In LPt(H2O)SO4???H2O the symmetry of the monodentate SO4 ligand appears to be lowered as a result of strong hydrogen bonding to the water molecules. The crystal structure of this compound has been determined by single-crystal X-ray diffraction. The monoclinic crystal, space group P21/c, has cell dimensions a = 13.615(9), b = 7.372(1), c = 14.702(2) ??, ?? = 109.26(4)?? and has four formula units in the unit cell. The structure was solved by standard methods and refined to R = 0.0337 based on 2671 reflections. The coordination of the metal atom is square planar with two nitrogen atoms, one oxygen of a water molecule and one oxygen of the sulfate anion being bound to platinum(II). There is extensive inter- and intramolecular hydrogen bonding. ?? 1986.