ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Hydrogen bond study in the crystallohydrates of double phosphites MCr(HPO₃)₂.nH₂O

M. Ebert and L. Kavan

Department of Inorganic Chemistry, Faculty of Natural Sciences, Charles University, 128 40 Prague

Abstract:  It was found that in the crystallohydrates of double phosphites  MCr(HPO₃)₂.nH₂O (M = Li, Na, K, NH₄; n = H—13) the hydrogen bonds between the water molecules mutually and between the water molecules and phosphite anions are formed. From the infrared molecular spectra the lengths and energies of these bonds were determined. The hydrogen bonds between the water molecules have a length 0.285—0.288 nm and the energy 19—21 kJ mol^-1 , while those between the water molecules and anions have a length 0.263—0.265 nm and the energy 42—47 kJ mol_-1 . According to these values, the phosphite anion belongs to the so-called positively hydrated anions and its influence is comparable with that of a phosphate anion. In the series of compounds MCr(HPO₃)₂.nH₂O  the energy of hydrogen bond between water molecule and anion increases with the decreasing size of cation of alkali metal.

Full paper in Portable Document Format: 304a425.pdf

Chemical Papers 30 (4) 425–429 (1976)