Synthesis and structural characterisation of the oxo-rhenium(V) complexes with spirophosphorane derived bidentate ligand (P∼O −). Crystal structure of trans-ReOCl 2[OCMe 2CMe 2OP(OCMe 2CMe 2O)](PPh 3)

Abstract

The reactions of ReO(OEt)Cl 2L 2, L=py, PPh 3 or ReOCl 3(Me 2S)(OPPh 3), with spirohydrophosphorane HP(OCMe 2CMe 2O) 2 – abbreviated here as HP∼O – in toluene yield ReOCl 2(P∼O)L complexes, L=py ( 1), PPh 3 ( 2) and OPPh 3 ( 3), respectively. The encountered bidentate phosphite pinacolato (OCMe 2CMe 2O)POCMe 2CMe 2O − ligand (P∼O −) is afforded by means of a spirophosphorane ring-opening reaction. All the pink–violet compounds 1– 3 were characterised by NMR, IR and UV–Vis spectroscopies. The structure of trans-ReOCl 2(P∼O)PPh 3 ( 2) was determined crystallographically. The rhenium atom adopts distorted octahedral geometry with a trans multiply bonded terminal oxo ligand (Re–O t=1.698(2) Å) trans to pinacolate oxygen (Re–O=1.880(2) Å). Two phosphorus atoms as well as two chlorides are mutually in a trans arrangement.