A complete active space self-consistent field study of the photochemistry of nitrosamine

Peláez, Daniel; Arenas, Juan F.; Otero, Juan C.; Soto, Juan

doi:10.1063/1.2360259

Cited by 26 publications

(50 citation statements)

References 42 publications

(46 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the other two bond lengths the ranges are narrower (1.171 to 1.191 Å and 1.178 to 1.198 Å for NO bond length of structures 1c and 1d, respectively; 1.020 to 1.024 Å and 1.020 to 1.023 Å for NH bond length of structures 1c and 1d, respectively) and the agreement between our results and the corresponding results of Ref. [27] is much better, with largest differences of 0.01 Å for the NO bond length and 0.02 Å for the NH bond length. In the case of the NO bond length our values are slightly larger, at the MP2 level, than the result of Ref.…”

Section: Resultssupporting

confidence: 92%

“…In the case of the NO bond length our values are slightly larger, at the MP2 level, than the result of Ref. [27], and slightly smaller at the other computational levels. However, for the NH bond length our results are slightly larger, at all computational levels.…”

Section: Resultscontrasting

confidence: 57%

“…With respect to the bond angles the larger difference between our results and the results of Ref. [27] is obtained for the HNH angle, with a maximum difference of 3.8°(again at the MP2/cc-pVTZ level). For the HNNO dihedral angle the major discrepancy is again obtained at the MP2/cc-pVTZ level, for which case our result is 6.3°smaller than the result obtained by Peláez et al It is important to mention that the results obtained at the MP2 level, using more extended basis sets (as the augcc-pVTZ and cc-pVQZ) did not yield the non-planar (1a) structure.…”

Section: Resultssupporting

confidence: 36%

“…[27] concerns the NN bond, with the best agreement obtained at the B3LYP/cc-pVTZ level. In this case, our results are smaller by at most 0.062 Å (CCSD/aug-cc-pVTZ result), and are in the range from 1.486 to 1.518 Å for structure 1c and 1.482 to 1.509 Å for structure 1d, depending on the method and basis set.…”

Section: Resultsmentioning

confidence: 87%

“…Some theoretical results suggest that only high-level ab initio (e.g., CASSCF) calculations can lead to a non-planar ground state minimum [1,28]. The highest level ab initio calculations on H 2 NNO have been performed by Peláez et al [27], using the CASPT2 method with the ANO-L basis set, and yielded a non-planar ground state minimum with an out-of-plane dihedral HNNO angle of 17.0°. On the other hand, CASPT2 calculations performed by Peláez et al yielded a planar C 2 NNO frame for the N-Nitrosodimethylamine molecule [14].…”

Section: Introductionmentioning

confidence: 98%

See 4 more Smart Citations

Ab initio and DFT conformational study on nitrosamine (H2N–N=O) and N-Nitrosodimethylamine [(CH3)2N–N=O]

et al. 2010

View full text Add to dashboard Cite

Ab initio and DFT calculations have been performed to characterize some ground state structures of the title molecules. Relative energies, rotational barriers, NBO charges, and dipole moments (l) have been calculated and analyzed. It has been confirmed that only highly correlated methods (e.g., CCSD) are able to yield the non-planar structure as a minimum, for the H 2 NNO molecule. On the other hand, all computational levels here employed are able to yield a planar C 2 NNO frame for the (CH 3 ) 2 NNO as a minimum. Important correlations between atomic charges and bond distances are discussed. Replacement of H by methyl group increases the rotational barrier and l values by at least 3 kcal/mol and 0.4 D, respectively. The largest l values are obtained for the structures in which the nitrogen lone pair is parallel to the NO group p system, and are consistent with a larger contribution of a dipolar resonance structure.

show abstract

Section: Resultssupporting

confidence: 92%

Section: Resultscontrasting

confidence: 57%

Section: Resultssupporting

confidence: 36%

Section: Resultsmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 98%

See 3 more Smart Citations

Ab initio and DFT conformational study on nitrosamine (H2N–N=O) and N-Nitrosodimethylamine [(CH3)2N–N=O]

et al. 2010

View full text Add to dashboard Cite

show abstract

Insights into the Thermal and Photochemical Reaction Mechanisms of Azidoacetonitrile. Spectroscopic and MS‐CASPT2 Calculations

Algarra

Soto

2020

ChemPhysChem

Self Cite

View full text Add to dashboard Cite

This work studies the photochemical and thermal decompositions of azidoacetonitrile (N3CH2CN) from both the experimental and theoretical points of view. The data of the photochemical experiments are taken from the literature, while the thermal decomposition have been carried out by us. In addition, we have performed ab initio calculations of the multiconfigurational type [complete active space self‐consistent field (CASSCF) and the multistate multireference perturbation theory (MS‐CASPT2)]. It is found that the first step of both type of decompositions is N2 elimination and formation of closed shell singlet nitrene. Afterwards, the nitrene tends to rapidly rearrange into formimidoyl cyanide (HNCHCN). As both reactions progress, the imine isomerizes into formimidoyl isocyanide (HNCHNC). The photoisomerization of the imine takes places thorough a conical intersection, while the same reaction on the ground electronic state occurs via a conventional transition state. The last step of the global reaction is decomposition of the imines into HCN and CNH. In photochemical conditions, the conjunction of the imines and its dissociation products (HCN and CNH) yields adenine

show abstract

Effect of methylation on relative energies of tautomers and on the intramolecular proton transfer barriers of protonated nitrosamine: A MR‐CISD study

et al. 2015

View full text Add to dashboard Cite

MR-CISD, MR-CISD+Q, and MR-AQCC calculations have been performed on the minima and transition states (corresponding to intramolecular proton transfer between the protonation sites) of the ground state of protonated nitrosamine and N,N-dimethylnitrosamine. Our highest level results (MR-AQCC/cc-pVTZ) for the smaller system indicate that protonation on the N amino (2a) is practically as favorable as the most favorable protonation on the O atom (1a). They also suggest that protonation on the nitroso N atom (2c) is ∼14.5 kcal/mol less favorable than 1a. Results obtained at the MR-CISD+Q/cc-pVTZ level indicate that the effect of methylation on the relative energies of the tautomers is, in order of importance, 2a > 2c and increases their energies by ∼17.5 and 4.8 kcal/mol, respectively. They also indicate that methylation alters significantly the intramolecular proton transfer barriers. The largest differences between the common geometric parameters of both systems have been found for 2a.

show abstract

A complete active space self-consistent field study of the photochemistry of nitrosamine

Cited by 26 publications

References 42 publications

Ab initio and DFT conformational study on nitrosamine (H2N–N=O) and N-Nitrosodimethylamine [(CH3)2N–N=O]

Ab initio and DFT conformational study on nitrosamine (H2N–N=O) and N-Nitrosodimethylamine [(CH3)2N–N=O]

Insights into the Thermal and Photochemical Reaction Mechanisms of Azidoacetonitrile. Spectroscopic and MS‐CASPT2 Calculations

Effect of methylation on relative energies of tautomers and on the intramolecular proton transfer barriers of protonated nitrosamine: A MR‐CISD study

Contact Info

Product

Resources

About