Pressure dependence of the infrared and visible spectra of metallophthalocyanine salts

The pressure dependence of the optical spectra was measured for highly conductive phthalocyanine radical salts, (phthalocyaninato) nickel(II) hexafluoroarsenate (NiPc(AsF6)0.5) and (phthalocyaninato) cobalt (II) hexafluoroarsenate (CoPc(AsF6)0.5). We found a pressure-induced charge transfer from the central metal ion to the macrocyclic ligand above the pressure of 2 GPa. This means that the concentration of the charge carriers is controlled by the pressure in these compounds.