A new clover-shaped trinuclear uranium(VI) complex: Synthesis, structure and photoluminescence property

A new clover-shaped trinuclear uranium(VI) complex of the formula [(UO2)(3)(phen)(3)(mu(3)-O)(mu(2)-OH)(2) (NO2)]center dot NO3 center dot 3DMF center dot H2O (1) (phen = 1,10-phenanthroline, DMF = N,N'-dimethylformamide) was prepared by reaction of UO2( NO3)(2)center dot 6H(2)O and phen under ultrasonic condition. X-ray single-crystal diffraction analysis shows that each U(VI) ion is in a seven-coordinated pentagonal-bipyramidal environment, with two 0 atoms in axial positions forming a uranyl ion. Each uranyl ion in 1 is coordinated by one chelating phen ligand and three 0 atoms at the equatorial plane. Interestingly, one central mu(3)-oxo incorporates two mu(2)-OH- and one NO to link uranyl ions into a clover-shaped motif. The molecules of 1 are packed within the space through hydrogen bonds, pi center dot center dot center dot pi and lone-pair center dot center dot center dot pi interactions. The solid diffuse-reflectance UV/vis and photoluminescence spectra of 1 were measured and discussed. (C) 2010 Elsevier B.V. All rights reserved.