%0 Journal Article %1 hlwoodcock:Q.1999-b %A Cui, Q. %A Morokuma, K. %D 1999 %J Theor. Chem. Acc. %K frequencies potential mechanism nonadiabatic approximation processes exchange energy bibtex-import model path surfaces %N 1-6 %P 127--133 %T The spin-forbidden reaction ch((2)pi)+n-2 -> hcn+n(s-4) revisited i. ab initio study of the potential energy surfaces %V 102 %X High-level ab initio electronic structure theories have born applied to investigate the detailed reaction mechanism of the spin-forbidden reaction CH((2)Pi); N-2 --> HCN = N(S-4). The G2M(RCC) calculations provide accurate energies for the intermediates and transition states involved in the reaction, whereas the B3LYP/ 6-311G(d.p) method overestimates the stability of some intermediates by as much as about 10 kcal/mol. A few new structures have been found for both the doubler and quartet electronic states, which are mainly involved in the dative pathways. However, due to the higher energies of these structures, the dominant mechanism remains the one involving the C-2v intersystem-crossing step. The C-2v minima on the seam of crossing (MSX) structures and the spin- orbit coupling between the doubler and quartet electronic states are rather close to those found in previous studies. Vibrational frequencies orthogonal to the normal of the seam which have been applied in a separate publication to calculate the rate of the CH((2)Pi) + N-2 + HCN + N(S-4) reaction with a newly proposed nonadiabatic transition-state theory for spin- forbidden reactions have been calculated at the MSX from first principles.

@article{hlwoodcock:Q.1999-b, abstract = {High-level ab initio electronic structure theories have born applied to investigate the detailed reaction mechanism of the spin-forbidden reaction CH((2)Pi); N-2 --> HCN = N(S-4). The G2M(RCC) calculations provide accurate energies for the intermediates and transition states involved in the reaction, whereas the B3LYP/ 6-311G(d.p) method overestimates the stability of some intermediates by as much as about 10 kcal/mol. A few new structures have been found for both the doubler and quartet electronic states, which are mainly involved in the dative pathways. However, due to the higher energies of these structures, the dominant mechanism remains the one involving the C-2v intersystem-crossing step. The C-2v minima on the seam of crossing (MSX) structures and the spin- orbit coupling between the doubler and quartet electronic states are rather close to those found in previous studies. Vibrational frequencies orthogonal to the normal of the seam which have been applied in a separate publication to calculate the rate of the CH((2)Pi) + N-2 + HCN + N(S-4) reaction with a newly proposed nonadiabatic transition-state theory for spin- forbidden reactions have been calculated at the MSX from first principles.}, added-at = {2006-06-16T05:03:46.000+0200}, author = {Cui, Q. and Morokuma, K.}, biburl = {https://www.bibsonomy.org/bibtex/22fada17e34b07540e8465c247dc09fe0/hlwoodcock}, citeulike-article-id = {569390}, comment = {210UP THEOR CHEM ACC}, interhash = {3f8351237ac797a2d0d741d5ad8de200}, intrahash = {2fada17e34b07540e8465c247dc09fe0}, journal = {Theor. Chem. Acc.}, keywords = {frequencies potential mechanism nonadiabatic approximation processes exchange energy bibtex-import model path surfaces}, number = {1-6}, pages = {127--133}, priority = {2}, timestamp = {2006-06-16T05:03:46.000+0200}, title = {The spin-forbidden reaction ch((2)pi)+n-2 -> hcn+n(s-4) revisited i. ab initio study of the potential energy surfaces}, volume = 102, year = 1999 }