Theoretical study on the reaction of Fe(~5D/~3D)+CH_2(~1A_1)→FeC+H_2
XU Jian-hua, HU Chang-wei · Journal of Atomic and Molecular Physics · 2006
The mechanism of reaction between CH_2(singlet state) and Fe(quintet and triplet states) was discussed in detail.All the structures of intermediate and transition states were optimized at UB3LYP/6-311+G(2d,2p) level of theory.Based on the optimized structures,single point energy correction was performed at UCCSD(T)/6-311+G(2d,2p) level of theory.The results indicated that the reaction in triplet and quintet states had a very similar energy surface.There were two transition states(TS1,TS2) and three intermediate states(FeCH_2,HFeCH,and H_2FeC) in both reaction energy surfaces.The energy surfaces of quintet and triplet states had an intersection before the formation of FeCH_2 intermediate,the reaction processes along with triplet state and the products were triplet FeC and H_2.The reaction was composed of four steps and the speed control step was the formation of H_2FeC from HfeCH,the activation energy was 176.3?kJ/mol.