75701-23-4Relevant academic research and scientific papers
Intramolecular rearrangements of sulfines coordinated to platinum. A unique equilibrium between oxidative-addition stereoisomers cis-(E)- and cis-(Z)-bis(triphenylphosphine)(methylthio)(arylsulfine)platinum(II) and the two stereoisomers of the reductive coupling product
Gosselink, Johan W.,Van Koten, Gerard,Spek, Anthony L.,Duisenberg, Albert J. M.
, p. 877 - 884 (2008/10/08)
An X-ray single-crystal study has revealed the molecular structure of bis(triphenylphosphine)(9-sulfinylfluorene)platinum(0)-0.5-benzene, [Pt0(PPh3)2(C12H 8CSO)]·0.5C6H6: monoclinic space group C2/c with unit cell dimensions a = 12.951 (4) A?, b = 17.958 (5) A?, c = 37.088 (8) A?, β = 98.48 (2)°, V = 8531.8 A?3, and Z = 8. The crystal structure was solved by standard Patterson and Fourier techniques. Anisotropic blocked full-matrix least-squares refinement with 5884 observed diffractometer data converged to RF = 0.038 (RwF = 0.041). The sulfine, C12H8CSO, is coordinated via η2-CS to the Pt(PPh3)2 unit. By comparison with the planar free sulfines, the C=S bond is lengthened and the C12H8 and SO groups bend out of plane. In CDCl3 the coordination compounds [Pt0(PPh3)2[(E)-(MeS)RCSO]] and [Pt0(PPh3)2[(Z)-(MeS)RCSO]] (R = Ph, P-MeC6H4; η2-CS coordinated sulfine stereoisomers) were both converted into an equilibrium mixture of the oxidative-addition stereoisomers cis-(E)- and cis-(Z)-[PtII(MeS)(PPh3)2(RCSO)] (in which the Pt0(PPh3)2 unit is inserted into the C-S side bond) and one coordination stereoisomer, [Pt0(PPh3)2[(E)-(MeS)RCSO]]. Individually, the cis-E and cis-Z stereoisomers were likewise converted into the same equilibrium mixture upon dissolution in CDCl3, which further illustrates the existence of a unique equilibrium between oxidative addition and reductive coupling products. Only traces of the specific stereoisomer [Pt0(PPh3)2[(Z)-(MeS)RCSO]] were found in the equilibrium mixture, indicating that η2-CS coordinated sulfines which contain a C-S side bond syn, as opposed to anti (with respect to the SO group), are more reactive toward oxidative addition to Pt0. A mechanism is proposed for the intramolecular oxidative-addition process, i.e., gliding movements along S-C=S frames via stereoisomeric intermediates [Pt0(PPh3)2[(E)-MeSC(R)SO]] and [Pt0(PPh3)2-[(Z)-MeSC(R)SO]], in which the sulfines are η3-SCS coordinated.
