Ternary complexes of uranyl ion with 1-phenyl-3-methyl-4-trifluoroacetyl-pyrazolone-5 and long chain sulphoxides

Ternary complexes of uranyl ion with PMTFP and aliphatic long chain sulphoxides, (R2SO: R=C4H9 to C11H22) have been synthesised and characterised. Analytical data establish that they have the stoichiometry, UO2(PMTFP)2.X where X=R2SO. The IR spectra of these complexes indicate that the S-O stretching frequency is shifted to lower frequency with respect to the neat ligand confirming bonding by oxygen. These spectra are typified by the characteristic and intense band of the O-U-O grouping at 915-925 cm-1 confirming chelation by the uranyl group. Bands at 450 and 360-370 cm-1 are ascribed to the U-O (pyrazolone) and U-O (sulphoxide) stretching frequencies respectively. The PMR spectra show two sets of signals of the phenyl protons of the pyrazolone group corresponding to the ortho and m, p protons. The enolic proton of the pyrazolone ligand has been found to occur as a broad band at 9.35 ppm which disappears on complexation indicating coordination. The alpha methylene protons of the sulphoxide in these complexes occur as 8 line multiplets at 3 ppm corresponding to an ABX2 pattern. (orig.)