Heterometallic alkoxides of alkaline earth metals: Synthesis, spectroscopic and chemical properties of new classes of tetra- and pentanuclear heterometallic alkoxides of barium and aluminium

Novel tetra- and penta-nuclear barium aluminium isopropoxides, BaAl3(OPri)(11) and Ba2Al3(OPri)(13), have been synthesized for the first time by the reactions (1:3 and 2:3) of barium metal and aluminium isopropoxide in isopropyl alcohol under refluxing conditions. The derivative BaAl3(OPri)(11) has also been prepared by refluxing equimolar amounts of Ba{Al(OPri)(4)}(2) and Al(OPri)(3) in benzene. Reactions of these two derivatives with tertiary alcohols (e.g., (BuOH)-O-t, (AmOH)-O-t, Et3COH) have been carried out to throw light on their possible structures. Characterization of all the highly hydrolyzable and monomeric derivatives has been made by elemental analysis, isopropoxy group analysis, molecular weight measurements, and spectroscopic [IR, NMR(H-1, C-13, Al-27)] methods.