1. Molecular structures and hydrogen bonding of 1:1 and 2:1 complexes of quinoline betaine with perchloric acid
- Author
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Szafran, Miroslaw, Katrusiak, Andrzej, Dega-Szafran, Zofia, Dymarska, Sylwia, and Grundwald-Wyspiańska, Monika
- Subjects
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PERCHLORATES , *HYDROGEN bonding , *MOLECULAR structure , *FOURIER transform infrared spectroscopy - Abstract
A novel anhydrous 1:1 and 2:1 complexes of quinoline betaine (QB) with perchloric acid have been prepared and their structures determined by X-ray diffraction. The 1:1 complex betaine is protonated and the carboxylate group forms a hydrogen bond with the ClO4 ion: O⋯O distance is 2.820(3) A˚. In the 2:1 complex, the carboxylate group of a pair of QB molecules are bridged by a proton to form dimeric cation in non-planar configuration, [(QB)2H]+, featuring a very strong hydrogen bond of the length 2.453(3) A˚. The FTIR spectrum of the 1:1 complex shows a strong absorption at ca. 3100 cm−1 due to the νOH vibration. Broad and intense absorption in the 1500–400 cm−1 region in the spectrum of the 2:1 complex is typical for the very short hydrogen bonds. B3LYP calculations predict slightly shorter hydrogen bonds with different orientation of the ring vs. COOH group than these observed in crystals. [Copyright &y& Elsevier]
- Published
- 2002
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