An investigation on the chemistry of the R2P=P ligand: reactions of a phosphanylphosphinidene complex of tungsten(VI) with electrophilic reagents

摘要

The nucleophilic properties of the title compound [(2,6-i-Pr2C6H3N)(2)(Cl) W(eta(2)-t-Bu2P=P)] Li center dot 3DME (1) were investigated in reactions with selected electrophilic reagents such as MeI, M(CO)(5)THF (M = Cr, Mo, W), AlCl3, and GaCl3. Methylation of 1 by MeI yields phosphanylphosphido complexes [(2,6-iPr(2)C(6)H(3)N) W-2(X)(1,2-eta-t-Bu(2)PvP-CH3)] (X = Cl, I) (2-Cl/2-I) with the formation of a new P-C bond. Moreover, 1 reacts with electrophilic compounds [(OC)(5)M center dot THF] (M = Cr, Mo, W) to yield a series of novel dinuclear phosphanylphosphinidene complexes [(2,6-i-Pr2C6H3N)(2)(Cl)W(1,2-eta-t-Bu(2)PvP-M(CO)(5))] Li center dot 3DME (3, 4, 5) with very long P-M distances. Adducts [(2,6-i-Pr2C6H3N)(2)(Cl)W(1,2-eta-t-Bu(2)PvP-MCl3)] Li center dot 3DME (6, 7) formed by reaction of 1 with GaCl3 and AlCl3 are labile and dissociate into 1 and MCl3 (M = Ga, Al). The outcomes of reactions were monitored by 31P-NMR spectroscopy. Furthermore, the structures of the isolated complexes 2-Cl/2-I, 3, 4, and [(2,6-i-Pr2C6H3N)(2)(Cl) W(1,2-eta-t-Bu(2)PvP-W(t-Bu2PH) (CO)(3)COLi center dot 2DME] (5-P) were confirmed unambiguously by X-ray diffraction studies.