(Ph3P)2Rh(SPCy2): A complex containing a side-on bonded η-secondary phosphine sulfide anion

Article abstract of DOI:10.1139/v88-415

The reaction of Cp2Zr(SPCy2)2 with either (Ph3P)3RhH(CO) or (Ph3P)4RhH led not to the expected heterobimetallic species but rather to a novel Rh species (Ph₃P)₂Rh(SPCy₂), 4. The ³¹P{¹H}NMR spectrum of this complex is an ABCX pattern. The molecular geometry of 4 was confirmed by a crystallographic study. Compound 4 crystallizes in the space group P2₁/c with a = 10.912(1) ?, b = 12.335(2) ?, c = 32.346(7) ?, β = 96.17(1)°, V= 4328(1) ?³, and Z = 4. The coordination sphere about Rh in 4 is pseudo-square planar, containing three phosphorus and a sulfur atom from the two coordinated phosphines and a side-on bonded SPCy₂ moiety. This structural study confirms that the secondary phosphine chalcogenide is bonded to Rh in an η² fashion. The complex 4 is only the fourth example in which this mode of binding has been crystallographically confirmed and is the first such species to involve one of the Pt group metals.