High pressure Raman spectra and pressure-induced phase transitions of β-9,10-dichloroanthracene

Abstract
The effect of pressure on Raman spectra and optical absorption of β-9,10-dichloroanthracene crystals has been investigated in a diamond anvil cell up to 8 GPa hydrostatic pressure. Two pressure-induced phase transitions at about 3 and 5 GPa are observed, the latter being associated with a large red shift of the absorption edge of the first π*←π transition. The structure of the high pressure phases is discussed on the basis of symmetry considerations.