Exploration on Au(S-4-py)PR3 complexes as a viable building block for constructing hetero-nuclear supramolecules:: synthesis and X-ray study on M(acac′)2[Au(S-4-py)PR3]2(ClO4)x (M = Cr, Cu; acac′ = acetylacetonate, hexafluoro-acetylacetonate; x=0 or 1)

Transition metal acetylacetonates, M(acac')(2)(ClO4)(x) (M = Cr, Cu; acac' = acetylacetonate, hexafluoro-acetylacetonate; x = 0 or 1) were reacted as a scaffolding for constructing a hetero metallic supra molecule with Au(S-4-py)L (L = PPh3, PPh2(2-py)) as a ligand. A trimetallic monomer, Au-Cr-Au, 5 was yielded from [Cr(acac)(2)(H2O)(2)]ClO4. However, [Cu(hfac)(2)] yielded a dimer 6 composed of a trimetallic monomer (Au-Cu-Au) moiety and an infinite chain polymer(.Au-Cu-Au.Au-Cu-Au.) 7 by virtue of aurophilicity in the solid state, the higher order structure of which depends on the co-existing ligand L. Basic structures of 6 and 7 are affected by L; 6 has a cis geometry, while 7 a trans geometry. Cooperative effect of the steric bulkiness of L and aurophilicity is presumed to determine the geometry. (C) 2004 Elsevier B.V. All rights reserved.