Theoretical Studies of the Effects of alpha -methylation and beta- methylation on the Gas - Phase Kinetics of Thermal Decomposition of Allyl formates

The gas phase pyrolytic reaction of allyl formate (I), its α-methylated compound (II) and β- methylated compound (III) were studied theoretically with semi-empirical PM3, hatree-fock HF/3-21G and density functional theory, DFT (B3LYP/6-31G*) methods. The decomposition of these compounds proceeds by a concerted [1, 5] hydrogen shift through a six-centered transition state (TS) geometry. The overall result of calculations shows that the reactivity of the thermal decomposition increases consequent to steric releasing effect in the transition state by the methyl group at the α-position, hence it is rate enhancing while reactivity decreases upon β-methylation, decreasing the rate of reaction. Also, it is found that rate enhancement due to C-O bond stretching in the formation of TS is more significant as a rate determinant than the acidic nature of the eliminated formyl hydrogen. Keywords: Kinetics, hydrogen shift, allyl formate, mechanism, α-,β-methylatio

Synthesis and Characterization of Pyridino(1,4-Η-cyclohexa-1,3-diene)Derivatives of Iron Tricarbonyl Complexes

In this synthesis, we have been able to show that, the addition of x- substituted pyridines, (X = H, 2- Me, 3- Me 4- Me, 4-NH2 and 4-N(CH3)2 to the dienyl ring of the organometallic cation, [(Fe(CO)3 (1-5- η-2-Me0C3H6)]BF4 and [(Fe(CO)3(1-5-η-C6H7)]BF4 gives ionic substituted diene products, (X C5H4-C6H6Y (Fe(CO)3] BF4,Y=H or 2-MeO. The reaction takes place at ordinary room temperature. The resulting products were isolated and characterized

African Journal of Pure and Applied Chemistry Ab-initio and DFT studies of the kinetics, mechanisms and thermodynamics of the gas-phase pyrolysis of ethyl bromide

The kinetics, mechanisms, thermodynamics and vibrational studies of the pyrolysis of ethyl bromide in the gas -phase at 623 K was studied using HF at 3-21G, 6-31G* and DFT with B3LYP/6 31G*, 6-311++G (2df, 2p) basis sets. The reaction proved to be a unimolecular reaction and followed a first order rate equatio

Evaluation of Some Manure Types for the Growth and Yield of Watermelon in Southwestern Nigeria

ABSTRACT: Extensive use of inorganic fertilizes has been discovered to have depressing yield effects on watermelon. This study was carried out at the Teaching and Research Farm of the Federal University of Technology, Akure (7 0 16'E, 5 0 12'E) located in the rain forest vegetation zone of Nigeria to evaluate the performance of watermelon grown under sub-optimal rates of application of three different types of manure. The treatment imposed were poultry manure at the rates of 4 t/ha, 6 t/ha, 8 t/ha and 10 t/ha; organic manure at the rates of 4 t/ha, 6 t/ha, 8 t/ha and 10 t/ha; organomineral fertilizer at the rates of 2.5 t/ha, 3.0 t/ha, 3.5 t/ha and 4.0 t/ha

Characterization of a novel polymeric Zinc (II) complex containing the anti- malarial Quinine as ligand: A Theoretical Approach (Semi-empirical and DFT methods)

ABSTRACT A novel polymeric zinc (II) complex of quinine, [chlorosulphato (2-ethenyl)-4-azabicyclo [2.2.2]oct-5-ylium-(6-methoxyquinolin-4-yl) methanol zinc (II)] has been synthesized and characterized. However, theoretical studies on the geometries, thermodynamic parameters, vibrational frequencies, geometric parameters, dipole moments, and band gaps of the complex were carried out. All these properties were obtained using the AM1, PM3 and DFT methods. Comparisons were made on the calculated bond distances, bond angles, dihedral and vibrational frequencies with the experimental data and it compared favourably well

PM3 Semi Empirical Quantum Mechanical Calculations on a Novel Dichlorobis (N-{4-[(2-pyrimidinyl-kN-amino)sulfonyl}acetamide]copper(II), Containing a Metabolite N-acetylsulfadiazine

ABSTRACT A novel Dichlorobi