High pressure Raman spectroscopic studies of (p−chloroanilinium){sub 2}CuCl{sub 4}

(p−chloroanilinium){sub 2}CuCl{sub 4} has a corner shared layered structure of CuCl6{sup 4−} octahedra with p-chloroanilinium cation sandwiched between the layers. The CuCl{sub 6} octahedra are irregular due to Jahn-Teller distortion. We report our high pressure Raman results on this compound in the present manuscript. Our results indicate significant changes in Raman spectra at ∼ 3 GPa and ∼ 8 GPa. The changes at 3 GPa can be attributed to a reduction in puckering of the CuCl{sub 4}{sup 2−} layer and the transition at 8 GPa, which also leads to a colour change of this sample to deep red, could be due to delocalization of the eg electrons along with a reduction of the cooperative Jahn-Teller distortion in this layer. These changes were found to be reversible.