(MALONATO)BIS[SULFINYLBIS[METHANE]-S]PLATINUM(II) COMPOUNDS - VERSATILE SYNTHONS FOR A NEW GENERAL-SYNTHESIS OF ANTITUMOR SYMMETRICAL AND DISSYMMETRICAL (MALONATO)PLATINUM(II) COMPLEXES

New (malonato)platinum(II) compounds, cis-[Pt(OOCACOO)(Me2SO)2] (A = CH2, cycloalkyl), have been prepared, and their reactions with various amines have led to a new general synthesis of antitumor symmetrical and dissymmetrical (malonato)-platinum(II) complexes. Reaction of trans-(−)-1,2-cyclohexanediamine (CHDA*) with the cyclobutanedicarboxylate (CBDC) complex cis-[Pt(CBDC)(Me2SO)2] has been studied in detail, and crystallographic molecular structure determinations have been carried out on the Pt(CHDA*)(Me2SO)(CBDC) intermediate and the Pt(CHDA*)(CBDC) product. Crystals of Pt-(CHDA*)(Me2SO)(CBDC) grown from aqueous solution form as unstable hydrates, which rapidly lose water molecules of crystallization upon removal from the crystallization solution at room temperature. X-ray data were collected on a crystal at −100°C. The complex crystallizes in the noncentrosymmetric triclinic unit cell Pl with four independent Pt(CHDA*)(Me2SO)(CBDC) molecules and thirteen independent water molecules per unit cell. Unit cell dimensions are a = 10.998 (3) Å, b = 13.946 (5) Å, c = 15.163 (5) Å, α = 65.39 (2)°, β = 88.21 (2)°, γ = 79.64 (2)°, and V = 2078 (1) Å3. Complex molecules form as two independent hydrogen-bonded dimers, [Pt(CHDA*)(Me2SO)(CBDC)]2, with hydrogen-bonded water molecules linking the two complex units. Platinum atoms of the complex are four-coordinate, bonded to the two nitrogens of the CHDA* ligand, the sulfur atom of the DMSO ligand, and one of the carboxylate oxygen atoms of the monodentate CBDC ligand. Crystals of Pt-(CHDA*)(CBDC) obtained from aqueous solution form as hydrates in the noncentrosymmetric centered monoclinic unit cell C2. Unit cell dimensions are a = 24.889 (16) Å, b = 5.382 (2) Å, c = 11.426 (4) Å, β = 106.97 (2)°, and V= 1464 (1) Å3, with one independent complex molecule and two half water molecules per asymmetric region of the unit cell. Displacement of the DMSO ligand of Pt(CHDA*)(Me2SO)(CBDC) results in chelation of the CBDC ligand in Pt(CHDA*)(CBDC). The two half water solvate molecules are hydrogen bonded to oxygen atoms of adjacent complex molecules. © 1990, American Chemical Society. All rights reserved.