STRUCTURE-ANALYSIS AND HYDROGEN-BOND CHARACTER OF K3H(SO4)2

Structure analysis of K3H(SO4)2 was performed by X-ray diffraction experiments in order to study the hydrogen bond character in connection with the geometrical isotope effect. Crystal data at room temperature were obtained as a=9.777(1)Å, b = 5.674(1)Å, c=14.667(4)Å, β=102.97(2)° and the space group A2/a, Z=4. The hydrogen bond length Roo determined from the positional parameters was 2.493(1)Å which was close to but still longer than the so called critical bond length rc. The electron density of split hydrogen atoms was observed on a differential Fourier map. It is concluded that the hydrogen atoms take the disordered state at room temperature and the distance between hydrogen atoms RHH is approximately 0.65 Å. The possibilities for the existence both of the low temperature phase and the high temperature prototype phase are discussed. phase transition, hydrozen bond material, structure analysis. © 1990, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.