Crystal structures and thermal properties of some rare earth alkoxides with tertiary alcohols

Abstract

Rare earth (RE) alkoxides of Y, La, Pr, and Gd were synthesized using three tertiary alcohols namely 2,3-dimethyl-2-butanol, 2,2-dimethyl-3-ethyl-3-pentanol, and 3-isopropyl-2,4-dimethyl-pentan-3-ol. 1H and 13C NMR, elemental analysis (CHN) and MS were used to characterize the complexes. New crystal structures of dimeric [Y(OCEt2 t Bu)3]2, [La(OCEt2 t Bu)3]2, [Gd(OC i Pr3)3]2, and [La(OC i Pr3)3]2 were solved. Thermal properties of these compounds were studied with TG/SDTA and vacuum sublimation experiments. With all the cations Y, La, Pr, and Gd, the compounds with smallest ligand i PrMe2CO− seem to be the most volatile. The compounds with larger alkoxo ligands have lower volatility but their thermal stability is better. Atomic layer deposition experiments showed that RE oxide thin films could be grown from these alkoxides using water as the oxygen precursor.