Pyridine-2-thionate as a versatile ligand in Pd(II) and Pt(II) chemistry: the presence of three different co-ordination modes in [Pd2(µ2-S,N-C5H4SN)(µ2-2S-C5H4SN)(µ2-dppm)(S-C5H4SN)2]

8 pages, 5 tables, 4 figures, 1 scheme.-- First published as an Advance Article on the web 28th Oct. 2005.Reactions of [MCl2(L–L)], M = Pt, Pd; L–L = bis(diphenylphosphino)methane (dppm) or bis(diphenylphosphino)ethane (dppe), with NaC5H4SN in a 1 : 2 molar ratio lead to mononuclear species [M(S-C5H4SN)2(P–P)], M = Pt; L–L = dppm ( 1) or dppe ( 2) and M = Pd; L–L = dppe ( 3), as well as to the dinuclear [Pd2(µ2-S,N-C5H4SN)(µ2-2S-C5H4SN)(µ2-dppm)(S-C5H4SN)2] ( 4). In contrast, reaction of [MCl2(dppm)] with NaC5H4SN in a 1 : 1 molar ratio leads to [Pd2(µ2-S,N-C5H4SN)3(µ2-dppm)]Cl ( 5) and trans-[Pt(S-C5H4SN)2(PPh2Me)2] ( 6) respectively. The latter is formed in low yield by cleavage of the dppm ligand. The dinuclear derivatives 4 and 5 present an A-frame and lantern structure, respectively. The former showing three different co-ordination modes in the same molecule with a short Pd–Pd distance of 2.9583 (9) Å and the latter with three bridging S,N thionate ligands showing a shorter Pd–Pd distance of 2.7291 (13) Å. Both distances could be imposed by the bridging ligands or point to some sort of metal–metal interaction.Financial support from MCyT-Spain-(BQU2002-04090-CO2-01 and BQU2002-00435) and JCyL-Spain-(BU15/03) is gratefully acknowledged.Peer reviewe