A nuclear quadrupole resonance and X-ray study of the crystal structure of pentachlorophenol

Abstract

Abstract : The crystal structure of pentachlorophenol was solved by the combined application of nuclear quadrupole resonance and X-ray diffraction. The molecules are linked by chains of hydrogen-bonds with a configuration similar to that in tetrachlorohydroquinone. The nuclear quadrupole resonance of one of the ortho chlorine atoms is specially affected by the intermolecular interaction. This interaction is attributed to the proton on the OH group of the adjacent molecule, and the existence of bifurcated hydrogen bonds with bond lengths O-H..O = 2.97 A and O-H..Cl = 3.28 A is inferred. During the phase determination, a pseudo solution was obtained, which was unusually close to the true solution. The relation between these two solutions is discussed. (Author)