NOVEL ANTIMONY(III) HALIDE COMPLEXES WITH SOME N-ALKYL THIOUREAS: SYNTHESIS, CHARACTERIZATION AND STUDY OF THEIR EFFECT UPON THE CATALYTIC OXIDATION OF LINOLEIC ACID TO HYDROPEROXYLINOLEIC ACID BY LIPOXYGENASE

Four novel antimony(III) compounds (SbX 3 ; X = Cl or Br) of thiourea derivatives; N-methylthiourea (NMTU)  and N-ethylthiourea (NETU) of formulae [SbCl 3 (NMTU) 3 ] ( 1 ), [SbBr 3 (NMTU) 3 ] ( 2 ), [SbCl 3 (NETU) 3 ] ( 3 ) and [SbBr 3 (NETU) 3 ] ( 4 ) were synthesized. These new antimony(III) halide compounds were characterized by melting point, elemental analysis, molar conductivity, FT-Infrared spectroscopy, FT-Raman spectroscopy, UV-Vis spectroscopy, NMR ( 1 H and 13 C) spectroscopy and TG-DTA analysis. The reactions of N-methylthiourea (NMTU) and N-ethylthiourea (NETU) with SbX 3 (X = Cl or Br) in a 2:1 ligand/metal rate but unexpectedly products were formed in a 3:1 ligand/metal rate. The compounds are non-electrolytes in solution and spectroscopic data of the compounds are appropriate with six coordinate octahedral geometry by three halide ions and three sulfur atoms from thiourea ligands. N-methythiourea and N-ethylthiourea ligands behave as monodentate in compounds 1 - 4 with the binding through sulfur.  The influence of these compounds 1 – 4 , N-methythiourea and N-ethylthiourea upon the catalytic peroxidation of linoleic acid to hyperoxolinoleic acid by lipoxygenase was kinetically studied.