Synthesis, structure and optic properties of 2-methylimidazolium and 2-phenylimidazolium uranyl acetates

Two new salts based on heterocyclic organic cations and uranyl triacetate anion were obtained via reaction of zinc uranyl acetate with 2-substituted imidazoles in presence of an excess of acetic acid. Uranyl triacetate anion in [2-MeImH](+) [UO(2)(CH(3)COO)(3)] and [2-PhImH](+) [UO(2)(CH(3)COO)(3)] H(2)O has an expected bipyramidal structure with linear uranyl group and three acetate groups laying in equatorial plane. [2MeImH](+) [UO(2)(CH(3)COO)(3)] structure analysis reveals H-bonded 1D chains connected through N-H center dot center dot center dot O hydrogen bonds. 2-phenylimidazolium in [2-PhImH]+ [UO(2)(CH(3)COO)(3)] H(2)O demonstrate planar geometry without any rotation of its rings, which was not registered before. H-bonds and pi-pi interactions of phenyl groups in this system lead to complicate 2D sandwich layer formation. The main features of IR-and luminescence spectrum of both compounds are also discussed. (C) 2009 Elsevier B.V. All rights reserved.