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On the Problem of Hydrogen Bonding in some calcium phosphates
Author(s) -
Petrov I.,
Šoptrajanov B.,
Fuson N.
Publication year - 1968
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.19683580309
Subject(s) - hydrogen bond , octacalcium phosphate , anhydrous , molecule , phosphate , hydrogen , chemistry , ion , calcium , infrared spectroscopy , crystallography , proton , inorganic chemistry , materials science , organic chemistry , physics , quantum mechanics
The hydrogen bonding by the acidic protons of the HPO 4 2−ion and by the water hydrogens was studied in the case of anhydrous dicalcium phosphate, dicalcium phosphate dihydrate and octacalcium phosphate, mainly on the basis of the analysis of the infrared spectra. The OH stretching, in‐plane bending and out‐of‐plane bending regions, as well as the region where the librational and „translational” modes of water are expected to appear were investigated. A distribution of the acidic hydrogen between more than two O's is indicated in the structure of CaHPO 4 , whilst this does not seem to be so in the case of CaHPO 4 · 2 H 2 O. It appears that several types of hydrogen bonds are present in the unit cell of CaHPO 4 . The water molecules in CaHPO 4 · 2 H 2 O are apparently of two types: some are coordinated onto Ca 2+ and involved in rather strong hydrogen bonding, whereas the rest are only weakly hydrogen bonded. The water molecules in octacalcium phosphate are also differently bonded.