Formation and structural characterization of novel polynuclear palladium selenolato complexes [Pd3Se(SePh)3(PPh3)3]Cl and [Pd6Cl2Se4(SePh)2(PPh3)6]

In addition to well-known dinuclear phenylselenolato palladium complexes, the reaction of [PdCl2(PPh3)(2)] and NaSePh affords small amounts of novel trinuclear and hexanuclear complexes [Pd3Se(SePh)(3)(PPh3)(3)]Cl (1) and [Pd6Cl2Se4(SePh)(2)(PPh3)(6)] (2). Complex 1 is triclinic, P (1) over bar, a = 13.6310(2), b = 16.2596(2), c = 16.9899(3) Angstrom, alpha = 83.1738(5), beta = 78.9882(5), gamma = 78.7635(5)degrees. Complex 2 is monoclinic, C2/c, a = 25.7165(9), b = 17.6426(8), c = 27.9151(14) Angstrom, beta = 110.513(2)degrees. There are no structural forerunners for 1, but the hexanuclear complex 2 is isostructural with [Pd6Cl2Te4(TeR)(2)(PPh3)(6)] (R = Ph, C4H3S) that have been observed as one of the products in the oxidative addition of R2Te2 to [Pd(PPh3)(4)]. Mononuclear palladium complexes may play a significant role as building blocks in the formation of the polynuclear complexes. (C) 2003 Elsevier B.V. All rights reserved.