DIOXOURANIUM(VI) COMPLEXES OF MONOBASIC BIDENTATE AND BIBASIC TETRADENTATE SCHIFF-BASES

A series of dioxouranium(VI) complexes were sythesised with the bidentate Schiff base ligands obtained by condensation of salicylaldehyde with aniline (pBH) or benzylamine (bBH), and the tetradentate Schiff base ligands derived by condensation of salicylaldehyde with ehtylenediamine (SpH2). The bidentate ligands formed complexes of the type UO2X2(pBH)n where X = NO-3, n = 2; X = CH3COO-, n = 1, and also the complexes UO2Cl2(pBH)2·H2O, UO2(CH3COO)(bBH)·H2O and UO2SO4(bBH)·EtOH·H2O. The tetradentate ligands formed the complexes UO2Cl2(SBH2)·EtOH, UO2SO4(SBH)1/2·EtOH·2H2O and also UO2Cl2(SpH2)1.5·2H2O, UO2(NO3)2(SpH2)1.5·EtOH and UO2(Sp)·EtOH. Conductivity measuremetns indicate that all the complexes are non-electrolytes in MeNO2 or MeCN solutions. IR spectral data suggest that the molecules and not the anions of the schiff base are coordinated to the central uranium atom, except for the complexes UO2(CH3COO)bB·H2O and UO2(Sp)·EtOH in which the deprotonated binegative ion is coordinated to the uranyl group. The acetato and sulphato groups are coordianted as bidentate ligands, while the nitrato group behaves as a unidentate ligand in the pBH complexes and as a bidentate ligand in the SpH2 complex. © 1979.