Synthetic, spectroscopic, and X-ray crystallographic studies on the uranyl(VI) complexes of the beta-diketophenol ligands 1-(2-hydroxyphenyl)-1,3-butanedione and 1-(2-hydroxyphenyl)-3-phenyl-1,3-propanedione

摘要

The preparation of the mononuclear complexes [UO2(HL1)(2)(MeOH)] and [UO2(HL2)(2)(EtOH)], the heterobinuclear complexes [UO2Mn(L-1)(2)(EtOH)]. 1.5H(2)O and [UO2Mn(L-2)(2)(EtOH)]. 2H(2)O, and the oxo-ligand adducts [UO2(HL1)(2)(Ph3AsO)]. 2H(2)O, [UO2(HL2)(2)(Ph3PO)] and [UO2(HL2)(2)(Ph3AsO)] (H2L1 = 1-(2-hydroxyphenyl)-3-butanedione and H2L2 = 1-(2-hydroxyphenyl)-3-phenyl-1,3-propanedione) is described. The complexes have been characterized by a variety of physicochemical techniques and the crystal structures of [UO2(HL1)(2)(EtOH)] and [UO2(HL2)(2)(EtOH)]. EtOH determined. Crystals of the former an triclinic, space group P1, a = 8.076 (1), b = 8.131 (1), c = 10.161 (1) Angstrom, alpha = 108.49 (1), beta = 112.26 (1), gamma = 89.89 (1)degrees and Z = 1. The latter is also triclinic, space group P (1) over bar, a = 12.184 (3), b = 15.578 (5), c = 9.035 (2) Angstrom, alpha = 91.05 (2), beta = 103.20 (2), gamma = 73.21 (2)degrees and Z = 2. Both complexes contain seven-coordinate uranium(VI) in a pentagonal bipyramidal geometry in which the two bidentate beta-diketonato ligands and the coordinated ethanol make up the equatorial pentagonal plane. For the complex [UO2(HL1)(2)(EtOH)] the HL1 ligands are in a trans arrangement with respect to one another, whereas for the [UO2(HL2)(2)(EtOH)]. EtOH complex the HL2 ligands adopt a cis arrangement. However, in solution variable temperature H-1 NMR spectra indicate that the cis and trans isomers are in equilibrium for both complexes. (C) 1998 Elsevier Science S.A. All rights reserved. [References: 38]