Synthesis and characterization of benzylselenolate complexes of palladium(II) and platinum(II)

Reactions of sodium benzylselenolate with several palladium(II) and platinum(II) complexes were carried out and a variety of products isolated and characterized. Reactions of Na2PdCl4 or K2PtCl4 with NaSeB2 gave [M(SeB2)](n) (M=Pd or Pt; Bz = CH2Ph) which when treated with tertiary phosphines yielded [M(SeBz)(2)(L-L)]. The latter can also be prepared by the reaction of MCl2(L-L) (L-L = dppm, dppe or 2PPh(3)) with NaSeBz. Treatment of [M2X2(mu -Cl)(2)(PR3)(2)] with NaSeBz in 1:2 molar ratio afforded complexes of the type [M2X2(mu -SeBz)(2)(PR3)(2)] (M = Pd or Pt; X = Cl or Me; PR, = PEt3, PPr3n, PBu3n, PMe2Ph, PMePh2 or PPh3) which existed predominantly as a cis isomer. Reaction of [M2Cl2(mu -Cl)(2)(PR3)(2)] with [M2Cl2(mu -SeBz)(2)(PR3)(2)] gave heterobridged complexes [M2Cl2(mu -Cl)(mu -SeBz)(PR3)(2)], the bridging chloride in the latter can be substituted with SBut or pz. All the complexes were characterized by elemental analysis and NMR (H-1, P-31, Se-77, Pt-195) spectral data. Stereochemistry of these complexes has been discussed on the basis of NMR data. The crystal structure of [Pt2Cl2(mu -SeBz)(2)(PPr3n)(2)] has established a cis configuration with a bent four-membered Pt2Se2 ring. The complex [Pd(SeBz)(2)](n) on thermolysis at 630 degreesC yields Pd17Se15. (C) 2001 Elsevier Science B.V. All rights reserved.