Homometallic glycolates containing hydroxyl functionality for anchoring another metal: synthesis and characterization of heterometallic alkoxide–glycolates of Ti and Zr incorporating Al and Nb

AbstractReaction of Ti(OPri)4 with 2-methyl-2,4-pentanediol [HOGOH, where G = CMe2CH2CH(Me)] in 1 : 3 M ratio under reflux afforded the monomeric [Ti(OGO)(OGOH)2] (1), which on further reactions with [Al(OPri)3] or [Nb(OPri)5] in 1 : 1 and 1 : 2 M ratios afforded heterometallic derivatives, [Ti(OGO)3{M(OPri)n−2}] and [Ti(OGO)3{M(OPri)n−1}2] [where M = Al (n = 3), Nb (n = 5)], respectively. Similar reactions of Zr(OPri)4∙PriOH with a number of glycols [HOGOH, where G = CH(Me)CH(Me), CMe2CMe2, CMe2CH2CH(Me)] yielded dimeric [Zr2(OGO)2(OGOH)4]. [Zr2(OGO)6{M(OPri)n−2}2] and [Zr2(OGO)4(OGOH)2M(OPri)n−2] [M = Al (n = 3), Ti (n = 4), Nb (n = 5)] were prepared by 1 : 2 and 1 : 1 reactions, respectively, of [Zr2(OGO)2(OGOH)4] with Al(OPri)3, Ti(OPri)4, or Nb(OPri)5. Surprisingly, a 1 : 2 reaction of [VO(OPri)3] with 2,2-diethyl-1,3-propanediol in benzene followed a different reaction and produced a neutral tetranuclear derivative [V4(O)4(μ-OCH2CEt2CH2O)2(OCH2CEt2CH2O)4] (18). All of these derivatives were characte...