Electrically-conductive nickelphthalocyanine polymer

Abstract

Thermal treatment of nickelphthalocyanine polymer having terminal carboxyl groups results in the formation of highly-conjugated structures and mobile radical defects, which cause an increase in the room-temperature electrical conductivity by seven orders of magnitude. The polymer was characterized by i.r., ESCA and elemental analyses. The heated polymer shows large paramagnetic susceptibilities and a dramatic increase in e.s.r. linewidth. The linewidth, intensity of e.s.r. and the magnetic susceptibility of the heated polymer decrease with increasing temperature. These results are explained by the presence of both localized and delocalized spins in the polymer network. The presence of adsorbed oxygen influences the ratio of the two types of spins. At low temperatures, localized spins dominate and at high temperatures most of the spins remain delocalized. The large electrical conductivity has been explained by the hopping of the mobile spins through the conjugated network polymer.