Ab initio method, under the effective core potential(ECP) approximation at HF/LANL2DZ level, has been employed to study the reaction mechanism of the carbonyl insertion of olefin hydroformylation catalyzed by a carbo...Ab initio method, under the effective core potential(ECP) approximation at HF/LANL2DZ level, has been employed to study the reaction mechanism of the carbonyl insertion of olefin hydroformylation catalyzed by a carbonyl cobalt HCo(CO)_3. The two reaction paths have been discussed. The calculated potential energy barriers for the carbonyl migration and the ethyl group migration are 105. 0 kJ/mol and 39. 17 kJ/mol, respectively. The results indicate that the reaction path via ethyl migration is more energetically favorable than that via carbonyl insertion.展开更多
Ab initio method under the effective core potential (ECP) approximation is employed to study the reaction mechanism of carbonyl migration of the cycle of olefin hydroformylation catalyzed by a carbonyl cobalt HCo(CO)3...Ab initio method under the effective core potential (ECP) approximation is employed to study the reaction mechanism of carbonyl migration of the cycle of olefin hydroformylation catalyzed by a carbonyl cobalt HCo(CO)3 at Hartree-Fock (HF) level. The structures of the reactant, transition state and product for the reaction are determined. The energy of each stationary point is corrected at MP2/LAN2DZ//LANL2DZ+ZPE (zero-point energy) level. The calculated activation barrier is 28.89 kJ/mol.展开更多
The whole catalytic cycle of the carbonylation of methanol to acetic acid catalyzed by Rh complex is theoretically studied. All structural geometries of reactant, intermediates, transition states and product are optim...The whole catalytic cycle of the carbonylation of methanol to acetic acid catalyzed by Rh complex is theoretically studied. All structural geometries of reactant, intermediates, transition states and product are optimized at HF/LANL2DZ level under the ECP approximation. The potential energy profiles for elementary reactions of carbonylation are calculated respectively. The transition states are further confirmed by having one and only one imaginary vibrational frequency. The results indicate that the activation energy values of CH3I oxidative addition, carbonyl insertion and CH3COI reductive elimination fundamental steps are 216.03, 128.10 and 126.55 kJ/mol, respectively; and that the CH3I oxidative addition step is predicted to be the rate-determining one.展开更多
文摘Ab initio method, under the effective core potential(ECP) approximation at HF/LANL2DZ level, has been employed to study the reaction mechanism of the carbonyl insertion of olefin hydroformylation catalyzed by a carbonyl cobalt HCo(CO)_3. The two reaction paths have been discussed. The calculated potential energy barriers for the carbonyl migration and the ethyl group migration are 105. 0 kJ/mol and 39. 17 kJ/mol, respectively. The results indicate that the reaction path via ethyl migration is more energetically favorable than that via carbonyl insertion.
文摘Ab initio method under the effective core potential (ECP) approximation is employed to study the reaction mechanism of carbonyl migration of the cycle of olefin hydroformylation catalyzed by a carbonyl cobalt HCo(CO)3 at Hartree-Fock (HF) level. The structures of the reactant, transition state and product for the reaction are determined. The energy of each stationary point is corrected at MP2/LAN2DZ//LANL2DZ+ZPE (zero-point energy) level. The calculated activation barrier is 28.89 kJ/mol.
基金the Young Teachers' Foundation of Beijing University of Chemical Technology (Grant No. QN0018).
文摘The whole catalytic cycle of the carbonylation of methanol to acetic acid catalyzed by Rh complex is theoretically studied. All structural geometries of reactant, intermediates, transition states and product are optimized at HF/LANL2DZ level under the ECP approximation. The potential energy profiles for elementary reactions of carbonylation are calculated respectively. The transition states are further confirmed by having one and only one imaginary vibrational frequency. The results indicate that the activation energy values of CH3I oxidative addition, carbonyl insertion and CH3COI reductive elimination fundamental steps are 216.03, 128.10 and 126.55 kJ/mol, respectively; and that the CH3I oxidative addition step is predicted to be the rate-determining one.
