η 1 ‐P basal Coordination of P 4 X 3 (X = S, Se) Molecules toward 16e Ruthenium Fragments

Ruthenium( II ) pentamethylcyclopentadienyl complexes [Ru(η 5 ‐C 5 Me 5 )Cl(L−L)] [L−L = 1,2‐bis(diphenylphosphanyl)ethane, dppe ( 1 ), bis(diphenylphosphanyl)methane, dppm, cis ‐1,2‐bis(diphenylphosphanyl)ethylene, dppet, and (1‐diphenylarsanyl‐2‐diphenylphosphanyl)ethane, dpadppe] treated with a stoichiometric amount of P 4 X 3 (X = S, Se) in THF have yielded the compounds [Ru(η 5 ‐C 5 Me 5 )(L−L)(P 4 X 3 )]BPh 4 (X = S, Se). In the P 4 Se 3 derivatives the heptatomic cage is bound to the metal through a basal phosphorus atom. The P 4 S 3 derivatives have been obtained as pairs of coordination isomers, with the cage linked either through the apical or through one of the basal P atoms, the latter form predominating (95% abundance), irrespective of the L−L ligand. The monometal complex [Ru(η 5 ‐C 5 Me 5 )(dppe)(η 1 P basal ‐P 4 Se 3 )]BPh 4 reacts with 1 to afford the dimetal compound [{Ru(η 5 ‐C 5 Me 5 )(dppe)} 2 (μ,η 1:1 ‐P basal ‐P apical ‐P 4 Se 3 )](BPh 4 ) 2 , where the cage exhibits both modes of bonding. The compounds have been characterized by NMR spectra ( 1 H, 13 C and 31 P) and elemental analyses. A theoretical analysis of the bonding properties of the two coordination isomer types is also presented. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)