The effect of organic cations on the structure of uranyl glutarate complexes

Abstract

Two novel uranyl glutarate coordination polymers were characterized by single crystal X-ray diffraction and IR spectroscopy. The structure of the first compound with [N(CH3)3(CH2C6H5)]2[(UO2)2(C5H6O4)3]·H2O (1) composition (where C5H6O42− = C3H6(COO−)2 = glt2− are glutarate anions) contains [(UO2)2(glt)3]2− chains with A2Q023 crystallochemical formula (CCF) (A = UO22+, Q02 = C5H6O42−). The second structure with [N(C2H5)4]2[(UO2)3(C5H6O4)4(H2O)2]·2H2O (2) composition contains another type of chains with [(UO2)3(glt)4(H2O)2]2− composition and A3Q024M12 (A = UO22+, Q02 = glt2−, M1 = H2O) CCF. 1D uranyl glutarate complexes in 1 and 2 differ in UO22+:glt2− ratio leading to the different topology. While [(UO2)2(glt)3]2− chains in 1 have a simple “ladder” topology common for uranyl dicarboxylates structures, in 2 [(UO2)3(glt)4(H2O)2]2− units have additional spacing due to the presence of extra uranium atom with different coordination. The topological difference is described in terms of coordination sequences. The analysis of non-covalent interactions in 1 and 2 was done in topos-Intermol program package and the small contribution of π-staking was revealed in 1.