(Diamine)tetracarboxylatoplatinum(IV) complexes, A(2)Pt(OOCR)(4) (A(2) = tr
ans-(+/-)-1,2-diaminocyclohexane (dach), 2,2-dimethyl-1,3-propanediamine (d
mpda), ethylenediamine (en), 2 NH3, 2 cyclopropylamine (cpa); R = CH3, C2H5
), have been facilely synthesized by reacting (diamine)tetrahydroxoplatinum
(Iv) with carboxylic anhydrides in dichloromethane, and their structural pr
operties were examined by X-ray analysis and H-1 NMR spectroscopy. The reac
tant (dach)Pt(OH)(4) crystallizes in the triclinic space group P (1) over b
ar (No. 2) with two molecules in an asymmetric unit and the local geometry
around the platinum(IV) atom is a regular octahedron, but the carboxylated
product (dach)Pt(O2CCH3)(4) crystallizes in monoclinic space group P2(1)/c
(No. 14) and the platinum(IV) atom is in a distorted octahedral environment
. The most interesting structural aspect of the title complexes is that the
equatorial Pt(IV)-carboxylate bonds are slightly longer than the axial one
s, probably due to the difference in trans influence of the nitrogen and ox
ygen donating atoms. The H-1 NMR spectra also show that the axial and equat
orial acetate groups are not equivalent. (C) 1999 Elsevier Science S.A. All
rights reserved.