DFT calculations, structural and spectroscopic studies on the products formed between IBr and N,N'-dimethylbenzoimidazole-2(3H)-thione and -2(3H)-selone

Dalton Trans. 2005 Jul 7:(13):2252-8. doi: 10.1039/b503883a. Epub 2005 May 31.

Abstract

The NBO charge distribution calculated at DFT level on the [LEX](+) species [LE=N,N'-dimethylbenzoimidazole-2(3H)-thione (3) and -2(3H)-selone (4)(Scheme 1); X=I, Br] suggests that the most likely products from the reaction 3 of 4 and with IBr are the 10-X-2 charge-transfer (CT) adduct and the 10-Se-3 "T-shaped" hypervalent adduct featuring a linear Br--Se--I system, respectively. This prediction is confirmed by the synthesis, and X-ray diffraction analysis of 3.IBr (I) and 4.I(0.72)Br(1.28)(II). In particular II, is a 10-Se-3 "T-shaped" hypervalent adduct containing an almost linear X--Se--X system [X--Se--X 179.07(3) degrees, X=I(0.36)/Br(0.64)], which is roughly perpendicular to the average plane of the benzoimidazole moiety. The FT-Raman spectra of I and II agree very well with their structural features. In particular, the complexity of the FT-Raman spectrum of II reflects the disorder in the X-ray crystal structure of this compound.

MeSH terms

  • Algorithms*
  • Benzimidazoles / chemistry*
  • Benzothiazoles / chemistry*
  • Biomedical Research*
  • Bromides / chemistry*
  • Iodides / chemistry*
  • Models, Molecular
  • Selenium Compounds / chemistry*
  • Spectroscopy, Fourier Transform Infrared
  • Spectrum Analysis, Raman
  • Thiones / chemistry*
  • X-Ray Diffraction

Substances

  • Benzimidazoles
  • Benzothiazoles
  • Bromides
  • Iodides
  • N,N'-dimethylbenzoimidazole-2(3H)-selone
  • N,N'-dimethylbenzoimidazole-2(3H)-thione
  • Selenium Compounds
  • Thiones
  • iodobromine