220244-10-0Relevant articles and documents
Syntheses, Structures, and Reactivity of Dinuclear Molybdenum-Platinum and Tungsten-Platinum Complexes with Bridging Carbonyl, Sulfur Dioxide, Isonitrile, and Aminocarbyne Ligands and a dppa Backbone (dppa = Ph2PNHPPh2)
Knorr, Michael,Strohmann, Carsten
, p. 248 - 257 (2008/10/08)
The heterodinuclear μ-carbonyl complexes [(OC)4M(μ-CO)(μ-dppa)Pt(PPh3)] (3a, M = Mo; 3b, M = W) are formed upon the reaction of [(OC)5M(η1-dppa)] (1a, M = Mo; 1b, M = W) with [Pt(C2H4)(PPh3)2]. After addition of p-tosylmethyl isonitrile to 3, the CO bridge is replaced by a bridging isonitrile ligand to afford [(OC)4W(μ-C=NCH2SO 2p-tolyl)(μ-dppa)Pt-(PPh3)] (4a, M = Mo; 4b, M = W). If stronger electron-donating isonitriles such as benzyl or 2,6-xylyl isonitrile are added to 3, fragmentation into mononuclear complexes occurs. Protonation of 4 leads to the μ-aminocarbyne complexes [(OC)4M{μ-CN(H)CH2SO 2p-tolyl}-(μ-dppa)Pt(PPh3)][BF4] (5a, M = Mo; 5b, M = W), which react further with isonitriles to yield the μ-aminocarbyne complexes [(OC)3(RNC)W{μ-CN(H)CH2SO 2p-tolyl}(μ-dppa)Pt-(PPh3)][BF4] 6, (R = 2,6-xylyl, benzyl). Purging a solution of 4a with SO2 yields the complex [(OC)4Mo(μ-SO2)(μ-dppa)Pt(PPh3)], 7a, in which a triphenylphosphine oxide ligand is bound via a hydrogen bridge to the N-H group of the dppa backbone. X-ray diffraction studies performed on 4b and 7a reveal that the μ-CNR and the μ-SO2 ligands bridge the metal centers in an asymmetric manner, the Pt-μ-C or Pt-μ-S distances being significantly shorter than the corresponding W-μ-C or Mo-μ-S distances, respectively.
