Pressure-induced d–π charge transfer in one-dimensional phthalocyanine conductors, NiPc(AsF6)0.5 and CoPc(AsF6)0.5

Abstract

Direct structural characterization of charge localization in metal to ligand charge transfer complexes AIP Conf.Pressure dependence of optical absorption spectra were measured for ͑phthalocyaninato͒-nickel hexafluoroarsenate, NiPc(AsF 6 ) 0.5 and ͑phthalocyaninato͒-cobalt hexafluororarsenate, CoPc(AsF 6 ) 0.5 . We found a charge transfer from the central metal ion to the macrocycle at 0.5 GPa in NiPc(AsF 6 ) 0.5 and 1.1 GPa in CoPc(AsF 6 ) 0.5 . According to the electron-filling process in the -conduction band, a metal-insulator transition and an evolution of the energy gap was observed in NiPc(AsF 6 ) 0.5 . On the other hand, nonmetallic CoPc(AsF 6 ) 0.5 showed a continuous change.

Spectroscopic studies of solid phthalocyanines and their charge transfer salts

“…9(b), shows the same pressure dependence as Fig. 9(a) [22,23]. In both cases the marker band C continuously vanishes upon applying pressure.…”

“…The suggestion on the transfer of charge and the question of where the charge comes from have been thoroughly investigated by a high-pressure transmission experiment on powered crystals in the infrared region [23]. The oxidation state of the Pc has been characterized by the intensity of some diagnostic local phonons.…”

“…14. The dotted curve is the absorption spectrum simulated by equation (8) assuming the Drude model [23]. The Drude parameters are taken from the analysis of the polarized reflection spectrum of the single crystal [12].…”

Technique for anisotropic extension of organic crystals: Application to temperature dependence of electrical resistance

“…1 Therefore, the remarkable changes in their transport, magnetic, and optical properties under a hydrostatic pressure are interpreted from the standpoint of increases in the intermolecular interactions. [2][3][4] As for anisotropic organic solids, the intermolecular interactions are expected to be enhanced by using anisotropic compression. The first investigation of the electrical resistance under anisotropic compression was reported in Ref.…”

Hyperfine structure and exchange coupling with conduction electrons in the quasi-one-dimensional organic metalCo0.01Ni0.99Simonyan1, Yonehara2, Ding3 et al. 2001Phys. Rev. B5040View full textAdd to dashboardCite

“…15 The crystals of CoPc and NiPc ͑Aldrich͒ were grounded together with the weighting factor of NiPc:CoPcϭ100:1. The mixtures were sublimed four times under a high vacuum to ensure intimate mixing.…”