Kinetics of Thermal Decomposition and Kinetics of Substitution Reaction of Nano Uranyl Schiff Base Complexes

Abstract

This study focuses on the synthesis, characterization, and kinetics of substitution reaction of new uranyl Schiff base complexes prepared in a crystalline state as well as in a form of nanoparticles with sizes ranging between 35 and 60 nm. Preliminary Fourier transform infrared spectroscopy (FTIR) and thermogravimetric (TG) measurements indicated no difference between the two forms. The compounds were characterized by UV-vis, 1 H NMR, cyclic voltammetry, X-ray crystallography, FTIR, TG, and CHN analyses. X-ray crystallography revealed coordination of the uranyl by the tetradentate Schiff base ligand and one solvent molecule, resulting in seven-coordinated uranium. Cyclic voltammetry of the complexes in acetonitrile revealed the quasi-reversible redox reaction. The TG and analysis of Coats-Redfern plots revealed that the kinetics of thermal decomposition of the complexes is of the first order in all stages. The study of the kinetics and the mechanism of the exchange reaction of the coordinated solvent with tributylphosphine was performed by the spectrophotometric method. The second-order rate constants at four temperatures and the activation parameters revealed an associative mechanism for all corresponding complexes. Anticancer activity of the nano uranyl Schiff base complexes against cancer cell lines (Jurkat) was studied and determined by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazoliumbromide) assay. C

Catalytic potentials of homodioxo-bimetallic dihydrazone complexes of uranium and molybdenum in a homogeneous oxidation of alkenes

“…Consequently, the catalytic potentiality of 1,2-cyclooctene oxidation is quantitative and highly selective to the corresponding oxide product with cis-MoO 2 complexes 1-3 which is 5 times more than that with U VI O 2 complexes 4-6 using either aqueous H 2 O 2 or TBHP as terminal oxidant in the same conditions. According to the less crystallographic data of 4-6, the most common geometry of the ligand around the two uranyl atoms is close to pentagonal bipyramidal with the axial O=U=O moiety, as reported before [40,44,45]. thermal oxidation of CO, NO, and volatile organic compounds [41,42].…”

Catalytic performance of binary and ternary oxovanadium complexes of dipyridinyl-urea in (ep)oxidation of cis-cyclooctene and 1-octene

“…The catalytic potential of oxovanadium complexes has been remarkably influenced by the nature of the solvent on (ep)oxidation processes, as reported recently [35][36][37][38]. The effect of different organic solvents in nature, i.e.…”

Catalytic Potential of Mononuclear Cr(III)-Imine Complexes for Selective Oxidation of Benzyl Alcohol by Aqueous H2O2

“…Many transition metal complexes are considered as high effective catalysts for such redox processes. The strong impact of the nature of the involved organic or inorganic solvent could be observed in such benzyl alcohol oxidation processes recently [35,36,37]. The influence of various solvents with different organic nature (i.e., acetone, dichloromethane, chloroform, and DMF (N,N -dimethyl formamide)) on the oxidation of benzyl alcohol by H 2 O 2 catalyzed by Cr(III)-imine complexes was investigated and summarized in Table 7.…”