DIOXOTUNGSTEN(VI) COMPLEXES OF ONO DONOR LIGANDS AND THE X-RAY CRYSTAL-STRUCTURE OF [WO2(O-OC6H4CH=NN=C(O)C6H5)(MEOH)]CENTER-DOT-MEOH

A general method for the preparation of dioxotungsten(VI) complexes of the type [WO(2)L(MeOH)] (where LH(2)=the Schiff's base derived from s alicylaldehyde or o-vanillin and benzoylhydrazide, salicylhydrazide, f uroylhydrazide, and isonicotinoylhydrazide) using [WO2(acac)(2)] (acac H=acetylacetone) as a precursor, is described. These complexes have be en characterized by elemental analysis, electrical conductance, IR, el ectronic, and NMR spectral, electrochemical, and magnetic susceptibili ty measurements. The structure of [WO2(o-C6H4CH=NN=C(O)C6H5) (MeOH)]. MeOH (1a . MeOH) has been determined by single-crystal X-ray diffracti on analysis. 1a . MeOH crystallizes in the space group Pbc2(1) with a= 6.992(2), b=16.190(2), c=31.390(4) Angstrom, V=3553.4(12) Angstrom(3), Z=8, R(F)=0.050, and R(w)=0.054. The tungsten atom has a highly disto rted octahedral coordination in which anionic oxygen atoms of the trid entate ligand are mutually trans and are cis to the cis-dioxo group.