Molecular structure and effects of intermolecular hydrogen bonding on the vibrational spectrum of trifluorothymine, an antitumor and antiviral agent


ÇIRAK Ç., KOC N.

JOURNAL OF MOLECULAR MODELING, vol.18, no.9, pp.4453-4464, 2012 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 18 Issue: 9
  • Publication Date: 2012
  • Doi Number: 10.1007/s00894-012-1449-5
  • Journal Name: JOURNAL OF MOLECULAR MODELING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.4453-4464
  • Erzincan Binali Yildirim University Affiliated: Yes

Abstract

In the present work, the experimental and the theoretical vibrational spectra of trifluorothymine were investigated. The FT-IR (400-4000 cm(-1)) and mu-Raman spectra (100-4000 cm(-1)) of trifluorothymine in the solid phase were recorded. The geometric parameters (bond lengths and bond angles) and vibrational frequencies of the title molecule in the ground state were calculated using ab initio Hartree-Fock (HF) method and density functional theory (B3LYP) method with the 6-31++G(d,p) and 6-311++G(d,p) basis sets for the first time. The optimized geometric parameters and the theoretical vibrational frequencies were found to be in good agreement with the corresponding experimental data and with results found in the literature. Vibrational frequencies were assigned based on the potential energy distribution using the VEDA 4 program. The dimeric form of trifluorothymine was also simulated to evaluate the effect of intermolecular hydrogen bonding on the vibrational frequencies. It was observed that the stretching modes shifted to lower frequencies, while the in-plane and out-of-plane bending modes shifted to higher frequencies due to the intermolecular N-Ha <-O hydrogen bonds.