Conformational analysis of N-methylformamide in ground S0 and excited S1 and T1 electronic states

Conformational analysis of N-methylformamide in ground S0 and excited S1 and T1 electronic states For conformers of the N-methylformamide (HCONHCH3) molecule, calculations of equilibrium geometry parameters, harmonic vibration frequencies, energy differences and potential barriers to conformational transitions were performed in the ground (S0) and lowest excited singlet (S1) and triplet (T1) electronic states. In the S0 state, the molecule exists in trans and cis stable conformations (having Cs symmetry). Our calculations show that the electronic excitations T1←S0 and S1←S0 cause changes in the structure of conformers: both HCON and HNCC fragments become pyramidal and rotate around the CN bond. As a result, in each excited electronic state under consideration, there are 12 minima forming six pairs of equivalent conformers separated by relatively small potential barriers. One- and two-dimensional potential energy surface sections corresponding to different intramolecular large-amplitude motions were calculated using the MP2/aug-cc-pVTZ (S0) and CASPT2/cc-pVTZ (S1 and T1) methods. Anharmonic vibrational problems for large-amplitude motions were solved, and the corresponding frequencies were estimated. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Quantitative Spectroscopy & Radiative Transfer Elsevier

Conformational analysis of N-methylformamide in ground S0 and excited S1 and T1 electronic states

Loading next page...
 
/lp/elsevier/conformational-analysis-of-n-methylformamide-in-ground-s0-and-excited-3R0XLHGtSq
Publisher
Elsevier
Copyright
Copyright © 2016 Elsevier Ltd
ISSN
0022-4073
eISSN
1879-1352
D.O.I.
10.1016/j.jqsrt.2016.02.012
Publisher site
See Article on Publisher Site

Abstract

For conformers of the N-methylformamide (HCONHCH3) molecule, calculations of equilibrium geometry parameters, harmonic vibration frequencies, energy differences and potential barriers to conformational transitions were performed in the ground (S0) and lowest excited singlet (S1) and triplet (T1) electronic states. In the S0 state, the molecule exists in trans and cis stable conformations (having Cs symmetry). Our calculations show that the electronic excitations T1←S0 and S1←S0 cause changes in the structure of conformers: both HCON and HNCC fragments become pyramidal and rotate around the CN bond. As a result, in each excited electronic state under consideration, there are 12 minima forming six pairs of equivalent conformers separated by relatively small potential barriers. One- and two-dimensional potential energy surface sections corresponding to different intramolecular large-amplitude motions were calculated using the MP2/aug-cc-pVTZ (S0) and CASPT2/cc-pVTZ (S1 and T1) methods. Anharmonic vibrational problems for large-amplitude motions were solved, and the corresponding frequencies were estimated.

Journal

Journal of Quantitative Spectroscopy & Radiative TransferElsevier

Published: Jul 1, 2016

References

  • Theoretical studies on the stability of N-methylformamide in both liquid and gas phases
    Cordeiro, J.M.M.; Cordeiro, M.A.M.; Bosso, A.R.S.A.; Politi, J.R.S.
  • The very low methyl group V3 barrier of cis N-methylformamide: A–E doubling from the free jet rotational spectrum
    Fantoni, A.C.; Caminati, W.; Hartwig, H.; Stahl, W.

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off