Influence of highly basic phosphine ligand on the reactivity and hydrolysis of P4 and P4S3 supported by ruthenium fragments

Substitution of PPh3 in [RuCp(PPh3)2Cl] with highly basic PMe3 gave a remarkable change in the reactivity towards P4 and unexpectedly only the bimetallic complex cation [{RuCp(PMe3)2}2(m,h1:1-P4)]2þ (3) was formed which was characterized by NMR spectroscopy and single crystal X-ray diffraction analysis. The equimolar reaction between the synthon [RuCp(PMe3)2]þ and the mixed cage P4S3 is highly selective quantitatively yielding only the product with h1-Pbasal coordination to ruthenium. On the other hand, the related [RuCp(PPh3)2]þ cation gave a 2:1 mixture of mono-h1-Pbasal and bimetallic complex. The solid state structure of [RuCp(PMe3)2(h1-Pbasal-P4S3)]þ (4) was solved by X-ray diffraction and represents the first example of X-ray structure of intact P4S3 coordinated to a mononuclear ruthenium organometallic fragment. Hydrolysis of the P4 ligand in 3 resulted mainly in two products, i.e. free H3PO3 and the diphosphane complex cation [{RuCp(PMe3)2}2(m,h1:1-P2H4)]2þ (9), while in the presence of methanol two mononuclear complexes [RuCp(PMe3)2{P(OH)3}]þ (8) and [RuCp(PMe3)2{P(OCH3)3}]þ (10) in (2:1) ratio were selectively formed.