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Polymorphism of 4-Fluorophenylpyruvic Acid Studied by X-Ray Crystallography and Vibrational Spectroscopy |
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| Authors: | Ko-Ki Kunimoto Kouji Kimura Takatomo Takai Hitoshi Senda Motoo Shiro Akio Kuwae |
| Affiliation: | 1. Department of Chemistry and Chemical Engineering, Faculty of Technology , Kanazawa University , Kanazawa, 920-1192, Japan E-mail: lee@kenroku.kanazawa-u.ac.jp;2. Rigaku Corporation , Akishima, 196-8666, Japan;3. Institute of Natural Sciences, Nagoya City University , Nagoya, 467-8501, Japan |
| Abstract: | Two polymorphic forms (I and II) of 4-fluorophenylpyruvic acid (F-PPA) were obtained by crystallization from different solvents, showing a melting point at 163.2 and 171.0 °C. Crystal structures of polymorphs I and II were determined by X-ray crystallography. IR and Raman spectra of the two polymorphs were measured and the spectral characteristics were compared with those of phenylpyruvic acid. the two polymorphs show similar molecular and crystal structures to each other, except for the molecular geometries of the enol and the carboxylic acid moieties. Distinct IR spectral differences which result from the crystal field splitting were observed between the two polymorphs. |
| Keywords: | 4-fluorophenylpyruvic acid polymorphism X-ray structure IR spectra Raman spectra |