38947-36-3Relevant academic research and scientific papers
Structural and photophysical properties of lanthanide complexes with N'- (2- methoxybenzylidene) - 2-pyridinecarbohydrazide Schiff base ligand: Catalyzed oxidation of anilines with hydrogen peroxide
Taha, Ziyad A.,Hijazi, Ahmed K.
, (2021)
Several lanthanide (III) complexes {Ln: La, 1; Sm, 2; Eu, 3; Gd, 4; Tb, 5; Dy, 6} with the Schiff base ligand, N'-?(2-?methoxybenzylidene)?-?2-pyridinecarbohydrazide, L, have been synthesized. These complexes having general formula LaL(NO3)3.xH2O and LnL2(NO3)3.xH2O, and the ligand L have been characterized by elemental analysis, spectral analysis (IR, 1H and 13C NMR), molar conductivity and thermogravimetric analysis. In the proposed structure of complex 1, La(III) ion is ten coordinate. Six coordination sites are satisfied by three bi-dentate nitrate ions, one site is occupied by H2O and the remaining three positions are occupied by ONO belonging to one neutral L. In contrast the lanthanide ion in the proposed structures of complexes 2 - 6, is twelve coordinated by two three bi-dentate ONO L and three bi-dentate nitrate anions. The photophysical properties of L and 1 – 6 in DMF solution have been investigated and reported. Complexes 1 - 6 catalyze the oxidation of aniline 1a and its derivatives 1b - 1 g using H2O2 as an oxygen source at an ambient conditions. Aniline is selectively converted to nitroso-benzene in the presence of complexes 2 and 3. Complexes 4 – 6 gave mixtures of nitrozo- and azoxybenzenes. With complex 1 a mixture of nitroso-, azoxy- and azobenzenes were obtained. Among the substrates tested, the best result was obtained in the case of 1e with 78.6% conversion and 100% selectivity for the nitroso-benzene in the presence of 4 as a catalyst.
