Reactivity of Diimido Complexes of Molybdenum and Tungsten towards Lithium Derivatives of Diphosphanes and Triphosphanes

The reaction of R2P-P(SiMe3)Li (R = tBu, iPr) with the diimido molybdenum complex [(ArN)(2)MoCl(2)dme] (Ar = 2,6-iPr(2)C(6)H(3); dme = 1,2-dimethoxyethane) yielded the side-on-coordinated phosphanylphosphinidene anionic complexes [(2,6-iPr(2)C(6)H(3)N)(2)Mo(Cl)((2)-P=PR2)](-) (7Mo, 8Mo). The thermal decomposition of [(2,6-iPr(2)C(6)H(3)N)(2)M(Cl)((2)-P=PR2)](-) [M = Mo (7Mo), W (8W)] to [(2,6-iPr(2)C(6)H(3)N)(2)M(Cl)(1,2--tBu(2)P=P-PtBu2)] [M = Mo (3Mo), W (3W)] was investigated by P-31{H-1} NMR spectroscopy. The reactions of [(ArN)(2)MCl(2)dme] (Ar = 2,6-iPr(2)C(6)H(3); M = Mo, W) with tBu(2)P-P(Li)-PtBu2 gave molybdenum and tungsten complexes [(2,6-iPr(2)C(6)H(3)N)(2)M(Cl)(1,2--tBu(2)P=P-PtBu2)] (3Mo, 3W) bearing an unusual triphosphorus ligand. The solid-state structures of [(2,6-iPr(2)C(6)H(3)N)(2)Mo(Cl)((2)-P=PtBu2)](-) (7Mo), [(2,6-iPr(2)C(6)H(3)N)(2)Mo(Cl)((2)-P=PiPr(2))](-) (8Mo), [(2,6-iPr(2)C(6)H(3)N)(2)Mo(Cl)(1,2--tBu(2)P=P-PtBu2)] (3Mo) and [(2,6-iPr(2)C(6)H(3)N)(2)W(Cl)(1,2--tBu(2)P=P-PtBu2)] (3W) were established by single-crystal X-ray diffraction analysis.