Synthesis and characterisation of heterobimetallic <Emphasis Type="Italic">N</Emphasis>-(hydroxyethyl)-salicylaldiminate–isopropoxide complexes of oxovanadium(V)

Soluble heterobimetallic-N-(hydroxyethyl) salicylaldiminate-alkoxide derivatives of the types [VO(L)2{M(OPr i ) n −1}] [M=Al (2) (n = 3); Ti (3), Zr (4) (n = 4); Nb (5), Ta (6) (n = 5)], [where L represents the dianionic N-(hydroxyethyl) salicylaldiminate group bonded to vanadium in a tridentate fashion involving both the oxygen atoms and azomethine nitrogen], have been prepared by the reactions of insoluble [VO(L)(LH)] (1) with different metal alkoxides in a 1:1 molar ratio in benzene. A monomeric heterobinuclear complex of the type [VO(η3-L)(μ-OPr i )2Al(η3-L)] (7) has been prepared by the equimolar reaction of [VO(η3-L)(μ-OPr i )]2 with [Al(η3-L) (μ-OPr i )]2 in benzene. All these complexes have been characterised by elemental analyses, molecular weight measurements, and by spectroscopic (l.r., 1H-, 27Al- and 51V-n.m.r.) studies. The monomeric nature of (1) and (2) has been supported by their FAB-mass spectral studies.