Synthesis and structure of uranyl complexes with carboxylic acids and oxygen containing neutral ligands

Abstract

Complexes [UO 2AC 2CH 3CON(CH 3) 2] 2, [UO 2(C 6H 5COO)·2(CH 3) 2SO 2] and [UO 2AC 2·1.5CO(NH 2) 2] were obtained by the interaction of the aquadiacidouranyl complexes with the neutral ligands. Single crystal X-ray diffraction studies show that [UO 2AC 2CH 3CON(CH 3) 2] 2 has dimeric structure and uranyl ion here is pentacoordinated. Crystal structure of the [UO 2(C 6COO) 2·2(CH 3) 2SO) 2] is built of monomeric complexes where uranyl ion is hexacoordinated, and structure of the [UO 2AC 2·1.5CO(NH 2) 2] is formed by the isolated complex [UO 2AC 2·3CO(NH 2) 2] + cations and [UO 2AC 3] − anions. Complex [UO 2Pr·1.5CO(NH 2) 2] is built in the same way, uranyl ions are penta- and hexa-coordinated. The uranyl complex with dicarboxylic succinic acid and DMSO [UO 2COOCH 2COO·(CH 3) 2SO] is built of chains where each acidoligand is bound in a bidentate way to one pentacoordinated uranyl ion, forming 4-membered cycle, and in a monodentate way to two other pentacoordinated uranyl ions. The crystal structure of the NH 4[UO 2Pr 3] is built of isolated complexes, each bidentate propionate ion forms a 4-membered cycle. The growth of the chains of monocarboxylic acids leads to predominance of the isolated forms of uranyl complexes.