Intramolecular Hydrogen Bonding in Guanidinium and Potassium Hydrogen Malonates - an Infrared and X-Ray Diffraction Study
نویسندگان
چکیده
A new modification of potassium hydrogen malonate was obtained by crystallization from dimethylsulphoxide (DMSO)' solution. Its infrared spectrum differs in its essential features from the spectra of the known modification crystallizing from water!-" but resemble those of guanidinium hydrogen malonate. Both spectra are interpreted in terms of strong, intramolecular hydrogen bonding, This is supported by the fact that the main features (CO and OH stretching) remain essentially unchanged on dissolution in DMSO and by the X-ray diffraction on guanidinium hydrogen malonate. The structure of its crystals was solved by the direct method and refined by full matrix least squares to R value of 0.044 for 453 observed reflections. The structure eonsists of planar guanidinium ions and hydrogen maleate residues containing short intramolecular, but asymmetric bonds of 2.407(3) A. INTRODUCTION
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