%0 Journal Article %1 ISI:000170111600015 %A Stevens, J. %A Schweizer, M. %A Rauhut, G. %D 2001 %J J. Am. Chem. Soc. %K chemie imported from:alexanderdenzel rauhut theoretische stuttgart theochem %N 30 %P 7326–7333 %R 10.1021/ja010792c %T Toward an understanding of the furoxan-dinitrosoethylene equilibrium %U http://dx.doi.org/10.1021/ja010792c %V 123 %X The tautomerism of furoxan (1,2,5-oxadiazole-2-oxide) has been investigated by different computational methods comprising modern density functionals as well as single-reference and multi-reference ab initio methods. The ring-opening process to 1,2-dinitrosoethylene is the most critical step of the reaction and cannot be treated reliably by low-level computations. The existence of cis-cis-trans-1,2-dinitrosoethylene as a stable intermediate is advocated by perturbational methods, but high-level coupled-cluster calculations identify this as an artifact. In contrast to the analogous reaction in benzofuroxans, cis-cis-cis-1,2-dinitrosoethylene was found to be a transition state rather than a local minimum. Model potentials were used to explain the occurrence and the disappearing of transition states and local minima relative to the reaction of benzofuroxan. Low-lying triplet states that can be accessed due to spin-orbit coupling were investigated as taking part in alternative routes to a proposed singlet pathway. Barriers for rotations of the nitroso groups on the S(0) and T(1) surfaces are reported.

@article{ISI:000170111600015, abstract = {The tautomerism of furoxan (1,2,5-oxadiazole-2-oxide) has been investigated by different computational methods comprising modern density functionals as well as single-reference and multi-reference ab initio methods. The ring-opening process to 1,2-dinitrosoethylene is the most critical step of the reaction and cannot be treated reliably by low-level computations. The existence of cis-cis-trans-1,2-dinitrosoethylene as a stable intermediate is advocated by perturbational methods, but high-level coupled-cluster calculations identify this as an artifact. In contrast to the analogous reaction in benzofuroxans, cis-cis-cis-1,2-dinitrosoethylene was found to be a transition state rather than a local minimum. Model potentials were used to explain the occurrence and the disappearing of transition states and local minima relative to the reaction of benzofuroxan. Low-lying triplet states that can be accessed due to spin-orbit coupling were investigated as taking part in alternative routes to a proposed singlet pathway. Barriers for rotations of the nitroso groups on the S(0) and T(1) surfaces are reported.}, added-at = {2019-02-15T17:47:57.000+0100}, author = {Stevens, J. and Schweizer, M. and Rauhut, G.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/267cf1b529b5ea09e9d3ae9a3190acef3/theochem}, doi = {10.1021/ja010792c}, interhash = {f3ac3389a7afd10767b93834e95ed522}, intrahash = {67cf1b529b5ea09e9d3ae9a3190acef3}, issn = {00027863}, journal = {J. Am. Chem. Soc.}, keywords = {chemie imported from:alexanderdenzel rauhut theoretische stuttgart theochem}, month = aug, number = 30, pages = {7326–7333}, pmid = {11472161}, timestamp = {2019-02-15T16:47:57.000+0100}, title = {{Toward an understanding of the furoxan-dinitrosoethylene equilibrium}}, url = {http://dx.doi.org/10.1021/ja010792c}, volume = 123, year = 2001 }