PREPARATION AND CRYSTAL-STRUCTURE OF BIS(CYCLOPENTADIENYL)TETRACARBONYLBIS(MU-2-PROPANETHIOLATO)DITUNGSTEN(II), [CPW(CO)2(MU-SCHME2)]2, AND BIS(CYCLOPENTADIENYL)DICARBONYLBIS(MU-2-PROPANETHIOLATO)DITUNGSTEN(II), [CPW(CO)(MU-SCHME2)]2

Warming CpW(CO)2(PPh3)SCHMe2 in THF gave the tetracarbonyl dimer [CpW(CO)2SOIIMe2]2 (1) with loss of PPh3 while further reaction in refluxing THF gave the dicarbonyl dimer [CpW(CO)SCHMe2]2 (2). The structures of 1 and 2 were determined. Crystal data for 1: Pnnm, a = 12.066 (9) Å, b= 12.246 (2) Å, c = 15.643 (2) A, V= 2311.41 Å3, Z = 8. Crystal data for 2: P21/c, a = 9.441 (4) Å, b = 1 1.727 (3) Å, c = 9.953 (4) Å, μ = 65.56 (3)°, V = 1101.94 Å3, Z = 4. In both structures, the thiolato groups bridge the two metal atoms, generating a nonplanar W2S2 core in 1 and a planar core for 2 that has a W=W bond (2.602 (5) Å). In 1, a crystallographically required mirror plane bisects the W-W vector and the Cp ligands, which are mutually cis while the CHMe2 groups are both in equatorial positions. A crystallographically required inversion center exists in 2, and therefore, the Cp groups are mutually trans, as are the CHMe2 groups. The possible geometric isomers of complexes of the type [CpM(CO)xSR]2 are discussed. © 1990, American Chemical Society. All rights reserved.