Synthesis, characterization and thermal decomposition of dioxouranium(VI) complexes with N1,N4-diarylidene-S-propyl-thiosemicarbazone: Crystal structure of [UO2(LI)(C4H9OH)]

Reactions of salicyl- and 3,5-dichlorosalicylaldehyde-S-propyl-thiosemicarbazones with salicyl- and 3,5-dichlorosalicylaldehyde in the presence of UO2(CH3COO)(2) in different alcohols yielded stable solid complexes corresponding to the general formula [UO2(L)ROH] (R: propyl-, butyl-, pentyl-, and octyl-). The complexes were characterized by means of elemental analysis, IR and H-1 NMR spectroscopies. The thermal stabilities of the alcohol solvated complexes were investigated in air and nitrogen atm., and determined their decomposition phases. In the crystal structure of the [UO2(L)(C4H9OH)], the U(VI) centre is seven-coordinated in a distorted pentagonal bipyramidal geometry involving O,O,N,N atoms of two phenolic and two imine groups and one oxygen atom of alcohol molecule in basal plane and two O atoms of dioxo group in apical positions. The title structure is stabilized by one intramolecular interaction of types C-H center dot center dot center dot Cl and by two intermolecular interactions of types O-H center dot center dot center dot O and C-H center dot center dot center dot pi (benzene) leading to the molecular chain along the [010] direction. (C) 2008 Elsevier B. V. All rights reserved.