Diverse Coordination Chemistry of the Whole Series Rare-Earth L-Lactates: Synthetic Features, Crystal Structure, and Application in Chemical Solution Deposition of Ln 2 O 3 Thin Films.

Rare-earth (RE, Ln) carboxylates are widely studied as precursors of RE oxide-based nanomaterials; however, no systematic studies of RE L-lactates (HLact = 2-hydroxypropanoic acid) have been reported to date. In the present work, a profound structural investigation of RE L-lactates is carried out. A family of RE lactate complexes of the general formula LnLact 3 ∙nH 2 O (Ln = La, Ce-Nd, Sm-Lu, Y; n = 2-3) are synthesized and characterized by CHN, TGA, and FTIR as well as by powder and single-crystal XRD methods.The existence of four novel structural types ( 1-Ln - 4-Ln ) is revealed. Compounds of the 1-Ln type (Ln = La, Ce, Pr) exhibit a chain polymeric structure, whereas 2-Ln - 4-Ln compounds are molecular crystals consisting of dimeric ( 2-Ln ; Ln = La, Ce-Nd) or monomeric ( 3-Ln -Ln = Sm-Lu, Y; 4-Ln -Ln = Sm-Gd, Y) species. The crystal structures of 1-Ln - 4-Ln compounds are discussed in terms of their coordination geometry and supramolecular arrangement. Solutions of yttrium and lanthanum lactates with diethylenetriamine are applied for the chemical deposition of Y 2 O 3 and La 2 O 3 thin films.