W 2(μ-H) 2Cl 4(μ-dppm) 2: the bulk synthesis of a bridging hydride

Abstract

The synthesis of the ditungsten species W 2(μ-H) 2Cl 4(μ-dppm) 2 marks the first bulk preparation of a bridging hydride W(III–III) species. The compound retains the characteristic edge-sharing bioctahedral (ESBO) geometry with a W W bond distance of 2.3918(7)Å. Although several Group VI ESBO complesxes have been prepared, only two with bridging hydride groups, W 2(μ-H) 2Cl 4(μ-dppm) 2 and W 2(μ-H) 2(μ-O 2CC 6H 5) 2 Cl 2(P(C 6H 5) 3) 2, have been reported to date. The complex W 2(μ-H) 2Cl 4(μ-dppm) 2 has been characterized with 31P 1H, 1H NMR, UV-vis, and IR spectroscopic techniques. A singlet is observed in the 31P 1H NMR spectra of W 2(μ-H) 2Cl 4(μ-dppm) 2 at δ = 20.464 ppm with J P−W = 126Hz and the IR spectra includes the tungsten-hydride symmetric stretch at 1602 cm −1.