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 1H 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⋯Cl and by two intermolecular interactions of types O–H⋯O and C–H⋯π (benzene) leading to the molecular chain along the [0 1 0] direction.