Lanthanum Propionate Monohydrate and Its Mixed-Ligand Complex with Diethylenetriamine: Synthesis, Crystal Structure, and Use in Chemical Solution Deposition of Lanthanum Nickelate Thin Films

A mixed-ligand complexation approach implying the reaction of metal carboxylates with the chelating tridendate diethylenetriamine (DETA) ligand has been applied to modify the structure of the layered coordination polymer based on lanthanum propionate (Prop). Lanthanum propionate monohydrate has been synthesized and characterized by a set of analytical methods to determine its crystal structure and chemical composition. The crystal structures of lanthanum propionate and nickel propionate complexes with DETA have additionally been determined. The native lanthanum propionate monohydrate [La 2 (H 2 O) 2 Prop 6 ] has been proven to have a 2D-layered topology, whereas the mixed-ligand complex [La 2 (DETA)Prop 6 ] ⋅ MeCN (where MeCN stands for acetonitrile) has a chain structure. A chemical solution deposition procedure has been developed to produce phase-pure oriented LaNiO 3 thin films. These films exhibit metallic conductivity and can be used as conductive sublayers.