The structures of some heterocyclic molecules

Abstract

An empirical method is described by which the structures of certain organic molecules may be calculated from rotation spectra measurements when the experimental data alone are insufficient to give a unique solution. The structures of pyridine, pyrrole, furan and thiophen have been calculated and are discussed. The application of the method to a straight-chain molecule is also considered.

Vibrational study of thiophene and its solvation in two polar solvents, DMSO and methanol by Raman spectroscopy combined with ab initio and DFT calculations

“…THP molecule has a relatively small dipole moment (0.55 D) and its interaction in gas phases is, therefore, mainly via weak non-specific solute-solute and solute-solvent interactions. There are few quite early experimental studies [17][18][19] and a recent theoretical study [20], which have dealt with structure determination of THP. Raman and NMR studies along with extended MO calculations using DFT on THP, 3-methylthiophene and selenophene have also been reported [21], which show a linear correlation between the calculated harmonic vibrational wavenumbers (scaled using SQM method) and experimentally observed wavenumbers for all the three molecules.…”

Kaolinite-Pyridine Intercalation Compound Derived from Hydrated Kaolinite

“…The layers were expanded by 4.8 A after the intercalation of pyridine. Pyridine in a perpendicular position has a thickness of about 6-7 ~ (Cumper, 1958); however, its size is slightly smaller in the interlayer space because of contraction (~ 1 /~) (Greene-Kelly, 1955). For example, the Na +-montmorillonite-pyridine intercalation compound showing a perpendicular orientation had a Ad value of 5.3 /k (Greene-Kelly, 1955).…”

Effects of Mechanical Deformation on the Opto-Electronic Responses, Reactivity, and Performance of Conjugated Polymers: A DFT Study

“…In fact, significant blueshift in the absorption spectra of polymer-based flexible devices has already been reported in the literature [ 35 , 95 ], being primarily associated with the disruption of aggregates in the active layer of the devices. Our results suggest that a similar effect can take place due to the reduced electronic coupling between adjacent units.…”

“…A tendency to ring opening was noticed for compounds containing five-membered heteroaromatic rings (PT and PPy); this is more evident for PT, where BL 1 , BL 2 , and BL 6 present very similar deformation rates. Although the PPy rings were not severely modified, significant changes are noted in relation to typical C–N bond lengths [ 95 ] (i.e., BL 1 and BL 2 > 1.309 Å).…”