The Microwave Spectrum of Imidazole; Complete Structure and the Electron Distribution from Nuclear Quadrupole Coupling Tensors and Dipole Moment Orientation

  title={The Microwave Spectrum of Imidazole; Complete Structure and the Electron Distribution from Nuclear Quadrupole Coupling Tensors and Dipole Moment Orientation},
  author={Dines Christen and J. H. E. Griffiths and J. Roger Sheridan},
  journal={Zeitschrift f{\"u}r Naturforschung A},
  pages={1378 - 1385}
Spectra have been measured for eleven isotopic forms of imidazole, including single substitutions at each nucleus in turn. A complete rs-structure is obtained. The ring structure is: N(1)-C(2) = 1.364 Å, C(2)-N(3) = 1.314 Å, N(3)-C(4) = 1.382 Å, C(4)-C(5) = 1.364 Å, C(5)-N(1) = 1.377 Å, ≮N(1)C(2)N(3) = 112.0°, ≮C(2)N(3)C(4) = 104.9°, ≮N(3)C(4)C(5) = 110.7°, ≮C(4)C(5)N(1) = 105.5° and ≮C(5)N(1)C(2) = 106.9°. The N(1)-H(1) distance is 0.998 Å, while the C-H distances are all very close to 1.078… 
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  • H. Giinthard, Chem. Phys. 1, 426
  • 1973