Synthesis, characterization and molecular structure of a dinuclear uranyl complex supported by N,N′,N",N′"-tetra-(3,5-di-tert-butylsalicylidene)-1,2,4,5-phenylenetetraamine

The preparation, characterization and the molecular structure of a dinuclear uranyl complex [(UO2)(2)L(OCMe2)(2)] supported by the bis-salophen ligand N, N', N '', N '''-tetra-(3,5-di-tert-butylsalicylidene)-1,2,4,5-phenylenetetraamine (L4-) is described. [(UO2)(2)L(OCMe2)(2)] was prepared by reaction of uranyl nitrate with the neutral, protonated form of the ligand (H4L) in acetone. From a saturated acetone solution [(UO2)(2)L(OCMe2)(2)]center dot 1.5(OCMe2) crystallizes triclinically, space group P (1) over bar with a = 1522.7(2), b = 1751.4(2), c = 1815.4(2) angstrom, alpha = 109.16(1), beta = 99.29(1), gamma = 105.29(1)degrees and Z = 2. Each uranium atom is surrounded in a distorted pentagonal bipyramidal fashion by two O and two N atoms of the salicylidene units, one O atom of an acetone ligand, and the two oxo groups. The cyclic voltammogram of [(UO2)(2)L(OCMe2)(2)] shows two quasireversible redox processes centered at +0.57 V and +0.82 V vs. Fc(+)/Fc attributed to the sequential oxidation of the coordinating phenolates to phenoxyl radicals. The crystal structure of an ethanol solvate of H4L was also determined by X-ray crystallography. H4L center dot 5EtOH: triclinic, space group P (1) over bar, a = 1003.4(3), b = 1187.7(3), c = 1905.1(5) angstrom, alpha= 75.75(2), beta = 78.74(2), gamma = 66.66(2)degrees, Z = 1.