loading page

A comparative multi-reference configuration interaction study of the low-lying states of two thione isomers of thiophenol.
  • +4
  • Filipe de Lima,
  • Gessenildo Pereira Rodrigues,
  • Juracy Lucena Jr.,
  • Elizete Ventura Do Monte,
  • Rui Fausto,
  • Igor Reva,
  • Silmar do Monte
Filipe de Lima
Universidade Federal da Paraiba
Author Profile
Gessenildo Pereira Rodrigues
Universidade Federal da Paraíba
Author Profile
Juracy Lucena Jr.
Universidade Estadual da Paraíba
Author Profile
Elizete Ventura Do Monte
Universidade Federal da Paraíba
Author Profile
Rui Fausto
Universidade de Coimbra
Author Profile
Igor Reva
University of Coimbra
Author Profile
Silmar do Monte
Universidade Federal da Paraíba
Author Profile

Abstract

Multi-reference configuration interaction, MR-CI (including extensivity corrections, named +Q) calculations have been performed on S0 to S3 states of cyclohexa-2,4-diene-1-thione (thione 24) and cyclohexa-2,5-diene-1-thione (thione 25), which are thione isomers of thiophenol. Several types of uncontracted MR-CIS and MR-CISD wavefunctions have been employed, comprising MR-CI expansions as large as ~ 374 x 106 configuration state functions. The nature of the studied excited states has been characterized. Vertical excitation energies (ΔE) and oscillator strengths (f) have been computed. The most intense transitions (S0→S2 for 24 and S0→S3 for 25) do not change with the wavefunction, although a variation as large as ~ 1 eV has been obtained for the S3 state of 24. On the other hand, ΔE changes at most ~ 0.15 eV for 25, as the wavefunction changes. The S1 state of both thiones has nπ* character and is in the visible region. For 24 S2 and S3 are ππ* and nπ* states, respectively, while for 25 the reverse order has been obtained. S2 and S3 are in the range from ~ 3.5 to 5.2 eV, at the highest level (MR-CI+Q). It is the first time that the excited states of the title molecules are studied. The computed results agree with the experimental onsets of photoreactions of thiones 24 and 25 found by Reva et. al. (Phys. Chem. Chem. Phys. 2015, 17, 4888).

Peer review status:ACCEPTED

13 Feb 2020Submitted to International Journal of Quantum Chemistry
14 Feb 2020Submission Checks Completed
14 Feb 2020Assigned to Editor
17 Feb 2020Reviewer(s) Assigned
11 Mar 2020Review(s) Completed, Editorial Evaluation Pending
12 Mar 2020Editorial Decision: Revise Minor
03 Apr 20201st Revision Received
06 Apr 2020Submission Checks Completed
06 Apr 2020Assigned to Editor
19 Apr 2020Reviewer(s) Assigned
19 Apr 2020Review(s) Completed, Editorial Evaluation Pending
19 Apr 2020Editorial Decision: Accept