The Crystal Structure of cis-Dichlorobis(dimethylsulfoxide)platinum(II)

Abstract

. Can. J. Chem. 53,2371Chem. 53, (1975. The molecular and crystal structure of cis-dichlorobis(dimethylsulfoxide)platinum(II), cis-[PtC12(DMSO)2], has been studied by X-ray diffraction. The compound belongs to the monoclinic P2Jc space group and the cell parameters are: a = 8.653, b = 13.580, c = 10.914 A, B = 123.43", and Z = 4. The refinement of the positional and anisotropic thermal parameters, carried out by full matrix least-squares calculations, converged to R = 0.029 and R, = 0.027.The coordination around the platinum atom is planar. As expected, the DMSO molecules are bonded to the platinum atom through sulfur. The bond distances found are: Pt-Cl = 2.306,2.312 A; Pt-S = 2.244,2.229 A; S-0 = 1.469, 1.454 A, and S-C = 1.77 to 1.79 A. IntroductionPtCl,(DMSO),, we have undertaken the study PtCl,(DMSO),, obtained as yellow crystals of the crystals by diffractionfrom the reaction between K,PtCl, and dimethylsulfoxide has variously been assigned the cis (1, 2) and the trans (3) configuration. The complex is not isomorphous with the corresponding Pd(I1) complex which is known, from X-ray diffraction studies, to have a trans configuration (4). Although the infrared spectrum indicates a cis configuration, the chemical behavior is more in keeping with a trans configuration (ref. 5, a note added in proof, confirmed the assignment of a cis configuration since the authors had just synthesized the trans isomer). There is general agreement that in the platinum-(11) complexes with one or two dimethylsulfoxide molecules, the ligands are bonded to platinum through sulfur. A strong peak around 1125 cm-' in the infrared spectrum has been assigned to the S-0 stretching vibration, indicating bonding through sulfur (6), since it is shifted to higher frequency than the corresponding vibration in the free ligand.Recently, we have decided to study the reactions between PtCl,(DMSO), and some nucleosides. In order to know the exact nature of Experimental SectionCrystal Data PtCl2C4H1zS2O2 f.w. Crystals of cis-dichlorobis(dimethylsulfoxide)platinum-(11) were obtained directly from the reaction of K2PtC14 in aqueous dimethylsulfoxide as previously described (1). A set of precession photographs indicated that the hOl, I = 2n + 1 and OkO, k = 2n + 1 reflections are systematic absences indicating the P2Jc space group. The cell parameters were calculated by least-squares refinement from the setting angles of 15 automaticaJly centered reflections (MoKu radiation) on a Syntex P1 diffractometer equipped with a graphite monochromator. Collection and Reduction of Intensity DataThe intensity data were collected from a crystal of dimensions 0.106 x 0.120 x 0.434 mm. A total of 3461 independent reflections were measured in the region of 20 < 60" by the 2010 scan technique using MoKu radiation. The data collection was done at a variable speed (24" to 1 dealmin) depending on the intensity of the reflection (~G t e x 20/0iutocoilection program). 3475 (2) 1681 (1) 2807 (2) 0 1 1779 (7) 537 (4) 4649 (5) 0 2 2529 (7) 2327 (3) 3250(6) CI -1079 (10...

Synthesis and structure of di-μ-hydroxo-bis[bis(dimethyl sulfoxide)platinum(II)] perchlorate

“…The O(1)-Pt-O(l') angle is reduced to 79.6 (4) ° while the Pt-O(1)-Pt angle is 100.4 (4) ° . These values are very close to those found in [Pt(NH3)2OH]22+ but are slightly different from those found in a Cl-bridged dimer where C1-Pt-CI' = 84.7 (1) and Pt-CI-Pt' = 95.3 (1) ° (Rochon & Melanson, 1981 (Melanson & Rochon, 1975, 1978a,b, 1984Melanson, Hubert & Rochon, 1976). The S atoms in the Me2SO molecules are in an approximate tetrahedral environment with angles ranging from 105.1 to 119.6 °.…”

“…Calculations performed on a Cyber 171 computer with programs already described (Melanson & Rochon, 1975). * Experimental.…”

“…Intensity data collected from a hexagonal plate with approximate dimensions 0.314mm 2697 reflections with I> 2.5o(11 considered observed; a(/) calculated as already described (Melanson & Rochon, 1975). Absorption correction based on equations of crystal faces applied to all reflections, transmission factors 0.059-0.470.…”

trans-Dichloro(dimethyl sulfoxide)(isopropylamine)platinum(II), C5H15Cl2NOPtS

“…density by flotation in a thallous malonate aqueous solution; hexagonal plate 0.6 mm by 0.08 mm thick; precession photographs indicated triclinic system; Syntex P1 diffractometer; graphite-monochromatized Mo K~t radiation; cell parameters from setting angles of 15 centered reflections (10 < 20 < 25"); 3626 independent reflections measured up to 20<60 ° by 0--20 scan technique; range of hkl: h-10--,10, k-12--,12, 1-12--,11; standard reflections 130, 410 and 0]-4: variations <3%; reflections with Inet<2.5ty(/) unobserved, o(/)calculated as in Melanson & Rochon (1975) (C-H=0.95 and N-H= 0.85/k) with isotropic fl=6.0/~ 2. R=0.035, R w = 0.049; w = 1/a2(F); (d/O')max in final refinement cycle <0.008; Pmax = 1.6 (close to Pt), Pmin = --0.5 e A -3 in final difference Fourier synthesis.…”

“…Atomic scattering factors of Cromer & Waber (1965) for Pt, CI, S, O, N and of Stewart, Davidson & Simpson (1965) for H; anomalous-dispersion terms of Pt, C1 and S from Cromer (1965). Calculations on a Cyber 171 with programs of Melanson & Rochon (1975).…”