Sharif Digital Repository

A joint theoretical and experimental study of the kinetic and mechanism of the rearrangement of allyl p-tolyl ether was performed in order to study the kinetic and mechanism of the reaction. Experimental studies were performed in gas phase over a temperature range of 493.15–533.15 K. The experimental Arrhenius parameters of this reaction were measured to be Ea = 36.08 kcal mol−1, ΔS# = −7.88 cal mol−1 K−1, and Log A = 11.74, experimentally. Using GC for the mixture of the reaction with and without cyclohexene demonstrated that the reaction is clean without any radical intermediates. The experimental results show that the studied reaction is unimolecular and proceeds through a concerted... 

A joint theoretical and experimental study of the kinetic and mechanism of the rearrangement of allyl p-tolyl ether was performed in order to study the kinetic and mechanism of the reaction. Experimental studies were performed in gas phase over a temperature range of 493.15-533.15 K. The experimental Arrhenius parameters of this reaction were measured to be Ea = 36.08 kcal mol-1, ΔS# = -7.88 cal mol-1 K-1, and Log A = 11.74, experimentally. Using GC for the mixture of the reaction with and without cyclohexene demonstrated that the reaction is clean without any radical intermediates. The experimental results show that the studied reaction is unimolecular and proceeds through a concerted... 

A combination of the experimental and theoretical study was carried out on the reaction mechanism associated with the pyrolysis of 2-pyridylacetic acid in the gas phase. Methylpyridine and carbon dioxide were analyzed as the products, using a static system over the pressure range of 18-55 torr and the temperature of 541.2-583.4 K. The experimental kinetic data show that the pyrolysis process is homogeneous, unimolecular and proceeds through a concerted mechanism. Theoretical studies at the B3LYP level using the 6-31G* basis set confirmed an asynchronous concerted mechanism for the reaction. Computed kinetic and activation parameters are in good agreement with the experimental one. © 2006... 

The mechanism and kinetic aspects of the retro-ene reaction of allyl n-butyl sulfide and its deuterated derivative were studied using four different types of density functional theory (DFT) methods with eight different levels of the basis sets. Vibrational frequency analysis confirmed that the stationary points include the transition state (TS) structure with only one imaginary frequency. Mechanistic studies on the retro-ene process rejected the step-wise mechanism and confirmed that the reaction proceeds through a six-centered cyclic transition state. Theoretical calculations show that propene elimination from the reactant can occur through an asynchronous concerted mechanism. A primary... 

The mechanism and kinetic aspects of the retro-ene reaction of the Allyl n-propyl sulfide and its deuterated derivative were studied using four different types of density functional theory methods with eight different levels of the basis sets. The activation energies were determined at 550.65 K. As a consequence of our calculations, a transition state is concluded that consists of a polar six-center cyclic structure. We found that the combination B3PW91/6-311++G** produces activation energy values closer to the experimental ones, but the simpler combination B3LYP/6-31G* produces excellent values too in less time. Our calculations show that the activation parameters obtained from the B3... 

Structural and kinetic aspects of the retro-cheletropic ene reactions of 2,2-dimethyl but-3-enal, 1-methyl-6-methylenecyclohexa-2,4-diene-1-carbaldehyde and their deuterated derivatives were investigated using a variety of computational methods. Theoretical calculations were carried out with ab initio and DFT methods at the RHF, MP2 and B3LYP levels of the theory, using the 6-31G* basis set. Vibrational frequency analysis confirmed the stationary states including the transition state (TSs) structures. Intrinsic reaction coordinate calculations show the localized TSs connect with the corresponding minima associated with the reactants and the products. The mechanistic studies on the...