Unexpected cis preference in palladium(II) bis( diphenylphosphinoarylthiolato) complexes. Crystal structure of cis- [Pd(PPh2(C6H4-2-S))(2)]

The complexes [Pd(PPh2(6-R-C6H3-2-S))(2)] (R=H (1); R=SiMe3 (2)) have been found to exist in solution as an equilibrium cis/trans mixture, the cis com plex being the major component in both cases. The use of a low polarity cry stallisation solvent allows the isolation of pure cis-1. The crystals of ci s-1 are monoclinic (P2(1)/n) with a = 15.559(2), b = 9.5224(9), c = 22.563( 3) Angstrom and beta = 91.91(1)degrees. The angles P-Pd-P of 100.57(3)degre es and S-Pd-S of 85.16(3)degrees deviate from the right angle to accommodat e the bulky-PPh2 groups in the square planar geometry. The use of polar CH, CN as a crystallisation solvent allows the isolation of trans-2. (C) 2000 E lsevier Science S.A. All rights reserved.