Stabilization of a Y-shaped Cu1 coordination in [CuPt2(PPh3)5(μ3-S) 2]PF6 by Pt2(PPh3)4(μ-S)2 and its expansion to a pentanuclear aggregate [Cu{Pt2(PPh3)4(μ3-S) 2}2]PF6.

Abstract

Addition of Pt2(PPh3)4(μ-S)2, 1, to an equimolar quantity of Cu(NO3)(PPh3)2 gave [CuPt2(PPh3)5 (μ3-S)2]NO3, 2a, which readily reacted with NH4PF6 giving [CuPt2(PPh3)5(μ3-S) 2]PF6, 2b. Further addition of a molar equivalent of 1 to 2b gave rise to a pentanuclear {CuPt4} complex of [Cu{Pt2(PPh3)4(μ3-S) 2}2]PF6, 3. Complex 3 was also obtained from the direct 2: 1 addition of 1 to [Cu(CH3CN)4]PF6. Complexes 2 and 3 have been characterized by IR and 31P-{1H} NMR spectroscopy and in the case of 2b single crystal X-ray crystallography. The geometry of Cu1 in 2b is three-coordinate and Y-shaped. It represents the first crystallographically characterized mixed-metal complex of 1 with a trigonal-planar heterometal. The unexpectedly short non-bonding Cu - Pt distances (av. 2.869(4) Å) are associated with a more open {Pt2S2} butterfly core (θ 137.5(5)°). Some theoretical aspects of these geometric peculiarities are discussed. Copyright © 1996 Elsevier Science Ltd.