Anomalous pressure effects on the Raman spectra in hydrogenhyphen;bonded molecular chain systems

摘要

Effects of hydrostatic pressure on the Raman spectra have been investigated for four kinds of 1,3hyphen;diketone crystals with hydrogenhyphen;bonded molecular chains. In all the crystals we studied, intense CO stretching Raman mode shows pressurehyphen;induced softening reflecting compression of the hydrogen bonds. Furthermore, application of pressure broadens the both C=O and Cndash;O stretching modes and intensifies several specific vibrational bands. We ascribed these spectral changes to formation or growth of the kinkhyphen;type defects of the hydrogenhyphen;bonded sequence.