Heterobinuclear PtAg compounds with platinum-silver bonds unsupported by covalent bridges. Molecular structure of (C6F5)3(SC4H 8)PtAgPPh3

Reaction of anionic platinum(II) derivatives (NBu4)[Pt(C6F5)3L] with O3ClOAgL′ affords the neutral heterobinuclear complexes (C6F5)3LPtAgL′ (L′ = PPh3, PEt3; L = SC4H8, PPh3, PEt3, PEtPh2, NC5H5) containing a direct Pt-Ag bond unsupported by covalent bridges. The molecular structure of a representative compound (L = SC4H8; L′ = PPh3) has been determined by a single-crystal X-ray diffraction study. The compound (C6F5)3(SC4H 8)PtAgPPh3 crystallizes in the monoclinic system, space group P21/n, with a = 14.006 (2) Å, b = 17.441 (3) Å, c = 17.407 (2) Å, β = 110.74 (1)°, V = 3977 (1) Å3, and Z = 4. The structure was refined to least-squares residuals of R = 0.0414, Rw = 0.0518, and quality of fit = 0.95. The platinum atom is in a square-pyramidal environment, with SC4H8 and the three C6F5 ligands in the square plane and the Ag-PPh3 moiety in the apical position. The Pt-Ag distance of 2.637 (1) Å is the shortest observed to date, indicating a direct Pt-Ag bond of substantial strength. The silver atom makes short contacts with o-fluorine atoms of the C6F5 groups (Ag⋯F(6) = 2.757 (7) Å; Ag⋯F(11) = 2.791 (7) Å; Ag⋯F(1) = 2.763 (8) Å). Acetone solutions of these complexes behave as 1:1 electrolytes because of cleavage of the Pt-Ag bond by the donor solvent. Addition of excess ligand L′ causes cleavage of the metal-metal bonds to give ionic derivatives of the type [AgL′n]+[Pt(C6F5) 3L]- (n = 2, 3). © 1987 American Chemical Society.We thank the U.S. National science Foundation and the CAYCIT (Spain) for financial support.Peer Reviewe