Preparation, properties, and crystal structure of acetonedi-isothio-cyanato-dioxobis(triphenylphosphine oxide)uranium(VI)

Abstract

The title compound is obtained by the interaction of uranyl(VI) chloride, potassium thiocyanate, and triphenyl-phosphine oxide in acetone–methanol mixtures, and by treatment of [UO₂(NCS)₂(PPh₃O)₂] with acetone at room temperature. The structure of this compound has been determined by single-crystal X-ray diffraction methods from diffractometer data and refined to a final R value of 0.047. It crystallises in space group Pna2₁ with a= 17.667(8), b= 9.112(5), c= 25.275(12)Å, and Z= 4. The seven-co-ordinate uranium atom is at the centre of a pentagonal bipyramid, the axis of which is defined by a linear uranyl(VI) group (U–O 1.78 and 1.70 Å). Bond distances to the coplanar equatorial atoms are U–N 2.44 (× 2), U–O(PPh₃) 2.36 and 2.38, and U–O(CMe₂) 2.56 Å.