Preparation and crystal structure of aqua[bis(2-hydroxyphenylimino)-ethanato-OO′NN′-]dioxouranium

Abstract

The preparation and X-ray crystal structure of the title complex determined by three-dimensional X-ray methods are reported. The blue crystals are monoclinic, space group P2₁/c, with cell dimensions: a= 7.834(9), b= 15.483(14), c= 11.824(13)Å, β= 92.65(7)°, and Z= 4. The structure was solved by the heavy-atom method from 2130 counter reflections, and refined by least-squares methods to R 0.067. The uranyl group is surrounded equatorially by a roughly regular pentagon formed by two oxygen and two nitrogen atoms of the Schiff base and by the oxygen atom of a water molecule. The pentagon is slightly puckered around the uranium, only the water oxygen having a significant deviation (0.12 Å). Bond lengths and angles are as expected [U–O (apical) 1.77(2) and 1.76(2), U–O(eq) 2.33(1) and 2.37(2), U–OH₂ 2.41(1), U–N 2.53(2) and 2.54(2)Å].