Synthesis and characterization of homo- and heterobimetallic diethanolaminates of alkaline earth metals

Heteroleptic heterobimetallic isopropoxide diethanolaminate derivatives of the type {Al(OPri)2}2{M[(OC2H4)2NH]2} (M=Mg, Ca, Sr, Ba) have been prepared by the reactions of homometallic precursor derivatives H2M{(OC2H4)2NH}2 (1a-1d) with Al(OPri)3 in 1:2 molar ratio in benzene. The insoluble homometallic precursor derivatives (1a-1d) have been synthesized by two alternative routes: (1) reactions of M(OPri)2 with diethanolamine in 1:2 molar ratio; and (2) reactions of the metals Mg, Ca, Sr and Ba with diethanolamine in 1:2 molar ratio in refluxing toluene. The new homo- and heterobimetallic diethanolaminate derivatives have been characterized by elemental analysis, molecular weight measurements and spectroscopic [IR, NMR (1H, 13C, 27Al)] studies