DINUCLEAR OXOVANADIUM(IV) COMPOUND WITH ALKOXYALCOHOL - SYNTHESIS AND STRUCTURAL STUDY OF (VOCL[OCH(CH3)CH2OCH3])2

The reaction between VOCl3 and 3 equivalents of sodium 1-methoxy-2-propanoxide in a mixture of toluene/1-methoxy-2-propanol leads, after removal of the salt and crystallization of the concentrated filtrate, to a vanadium(IV) compound which has been characterized by the usual techniques (elemental analysis, IR, MS, EPR, H-1 and V-51 NMR) and X-ray diffraction as a dimeric five-coordinate oxovanadium(IV) chloride dialkoxide, {VOCl[OCH(CH3)CH2OCH3]}2. This compound can also be obtained from VOCl3 with 1-methoxy-2-propanol in THF using ammonia gas. One of the two oxygen atoms from each methoxyalkoxo group bridges the vanadium centres yielding a planar V2O2 core. Surprisingly, a cis configuration around the V-O-V-O ring is adopted both by oxo groups and chlorine atoms.