Structure and reactivity of [PtX2(ketoxime)2] compounds.: Cis-trans isomerization and X-ray structures of cis-[PtBr2(Me2C=NOH)2] and trans-[PtBr2(Me2C=NOH)2]•2MeC(=O)NMe2

The solid slate thermal isomerization of cis-[PtX2(ketoxime)(2)1] (X = Cl, ketoxime = Me2C = NOH, (CH2)(4)C = NOH, (CH2)(5)C = NOH;X = Br, ketoxime = Me2C = NOH) gives the corresponding ti ails-isomers in almost quantitative yields, thus showing that solid state isomerization is a general and convenient procedure for the synthesis of trans-[PtX2(ketoxime)(2)] complexes. X-ray structure analyses were performed for both cis-[PtBr2(Me2C = NOH)(2)] and the bis-dimethylacetamide solvate of trans-[PtBr2(Me2C = NOH)(2)]. The former compound crystallizes in the orthorhombic space group Pbca with a = 9.593(1), b = 14.827(2), c = 17.218(2) Angstrom; V = 2449.0(8) Angstrom(3), Z = 8, and rho(calcd) = 2.718 cm(-3). The latter complex crystallizes in the orthorhombic space group Pbca with a = 10.543(2), b = 17.676(4), c = 12.398(2) Angstrom; V = 2310.5(8) Angstrom(3), Z = 4, and rho(calcd) = 1.941 g cm(-3). These two compounds are the first structurally characterized representatives of neutral Pt complexes with "simple" oximes. (C) 1998 Elsevier Science Ltd. All rights reserved.