THE LATTICE-DYNAMICS OF BETA-HYDROQUINONE CLATHRATE

Dynamic properties of beta-hydroquinone (Q(beta)) clathrate with various guest molecules have been calculated by the method of lattice dynamics within the atom-atom potential approximation; van der Waals interactions, H-bond interactions, and electrostatic interactions for charges localized on the atoms are included. External vibration spectra have been calculated for the empty framework of Q(beta) and with different guest molecules (HCN, CO2, SO2, C2N2, C2H6, CH3OH, O2CO). Vibrational frequencies of the guest molecules in cavities are determined. The phonon density of states for these compounds has been calculated. The influence of the encaged guest molecules on the vibrational spectrum of the host lattice has been investigated. The most visible changes are observed upon the insertion of guest molecules with large dipole moment or those positioned asymmetrically inside the Q(beta) clathrate cages. Peculiarities of different interactions have been revealed. Analysis of the calculated and experimental results have been carried out. (C) 1995 American Institute of Physics.