Structure and Internal Rotation in 3-Phenylthiophene Using NMR Spectra of Liquid-Crystalline Solutions

Article abstract of DOI:10.1016/0022-2364(83)90296-2

The NMR spectra of 3-phenylthiophene as solute in liquid-crystal solvents were analyzed and the direct couplings constants, D_ij obtained were used to test different models of the potential energy function V(φ) for intramolecular rotation of the phenyl and thiophene units.The data are consistent with a V(φ) having a minimum at about 24 deg.The LCNMR technique is highly discriminant among different models of V(φ) provided that enough D_ij couplings are available.Ab initio calculations are also reported.