Compressibility of one dimensional phthalocyanine conductors, NiPc(AsF6)0.5 and CoPc(AsF6)0.5

Powder X-ray diffraction patterns of phthalocyanine conductors, NiPc(AsF6)0.5 and CoPc(AsF6)0.5, were measured under high pressure. The crystal symmetries of these compounds were maintained in the pressure range of 0 − 4.1 GPa. The contraction along the stacking axis is larger than that perpendicular to the axis. This difference becomes clear at the pressure where the metal-ligand charge transfer occurs. The relation between the lattice contraction and the pressure-induced metal-ligand charge transfer is discussed.