Preparation and characterisation of heterobimetallic copper–tungsten hydride complexes

Abstract

The preparation and structural characterisation of three new heterobimetallic hydride complexes containing 3-centre,2-electron W-H-Cu bonds is reported. These complexes have been characterised by single crystal X-ray crystallography and multinuclear NMR spectroscopy. The bonding in these complexes has been analysed by DFT calculations.

Tweaking the bridge in metallocene Zr(iv)/W(iv) bimetallic hydrides

“…Presumably due to geometric constraints, the two hydrides are tilted out of the Zr coordination plane. This is not an ideal geometry for donation to Zr (although “mismatched” Cp 2 WH 2 orientation has also been reported for a Cu( i ) complex 59 ), and perhaps due to this we find for complex 7a a small amount of Zr mixing into the W LP (.046 e). Still, the overall pattern of dominant WH donation and relative inertness of the W lone pair seems to hold also for the alkyne adducts.…”

“…Recent computational work suggests that the latter bonding mode is preferred. 59,60 (Cp 2 MoH 2 has also been found to form metal complexes, 29,[60][61][62][63] for which similar bonding options are conceivable). We have used IBOview (IBO: Intrinsic Bond Orbital) 64,65 to analyse the situation; Fig.…”

Zintl cluster supported low coordinate Rh(i) centers for catalytic H/D exchange between H2and D2

“…The single hypersilyl resonance observed at room temperature points to a uxional process that makes these groups equivalent on the NMR timescale, as also noted for [Rh(dppe){h 5 -Ge 9 (Hyp) 3 }]. 10 The related clusters [Rh(PPh 3 ){h 3 -Ge 9 (Hyp) 3 }] (1b), [Rh(IMe 4 ) {h 3 -Ge 9 (Hyp) 3 }] (1c), and [Rh{h 3 -Ge 9 (Hyp) 3 }(m-H) 2 W(Cp) 2 ] (1d) were synthesized in a similar manner, from the reaction of [Rh(COD){h 4 -Ge 9 (Hyp) 3 }] with one equivalent of the L-type ligands PPh 3 , IMe 4 (IMe 4 ¼ 1,3,4,5-tetramethylimidazol-2ylidene) or [W(Cp) 2 H 2 ], [12][13][14][15] respectively. Clusters 1b-1d exhibit similar NMR spectra to 1a (see ESI † for full details), and are thus also uxional at room temperature.…”