MIXED OLEFIN CARBONYL-COMPLEXES OF PLATINUM(II)

The reaction of cis-PtCl2(CO)2 with cycloheptene in dichloromethane yielded CiS-PtCl2(CO)(C7H12) (1), characterized by X-ray diffraction methods. The dimeric bromide Pt2Br4(CO)2 and cycloheptene in CH2Cl2 Solution after workup and precipitation with heptane yielded a mixture of two solids, one of which, 2, was found crystallographically to be Pt2Br4(C7H12)2.2[cis-PtBr2(CO)(C7H12)], an infrequent case of cocrystallization of two different molecules. Compound 1 crystallizes in the orthorhombic space group Pbcm with a = 10.679(3) angstrom, b = 13.533(1) angstrom, c = 7.459(4) angstrom, and V = 1078(1) angstrom3 for Z = 4. Least-squares refinement of 1083 observed unique reflections gave R = 0.042 (R(w) = 0.048). Compound 2 crystallizes in the triclinic space group P1BAR with a = 7.106(3) angstrom, b = 11.872(2) angstrom, c = 12.908(7) angstrom, alpha = 72.79(3)-degrees, beta = 84.15(2)-degrees, gamma = 81.96(2)-degrees, and V = 1078.1 angstrom3 for Z = 2. Least-squares refinement of 3637 observed reflections gave R = 0.047 (R, = 0.056).