Partially oxidized Group 3B fluorometallophthalocyanines

Abstract

The fluorine-bridged Group 3 metal phthalocyanines [{M(pc)F}_n](M = Al or Ga) have been reacted with nitrosonium salts NO⁺Y^–(Y = BF₄ or PF₆). Pressed pellets from the products of these reactions have conductivities as high as 10 Ω^–1 cm^–1. Pellet conductivities are maintained indefinitely in ambient air. Samples are thermally stable (thermogravimetric analysis) up to ca. 150 °C. Thermally-ramped mass spectra show that primary decomposition products are fluorinated organic compounds and anion fragments. X-Ray powder diffraction data show that new diffraction lines are formed on doping these stacked polymers. It is believed that these new lines correspond to some disruption of the original crystal lattice. A broad electronic transition is detected in the i.r. spectra of the doped products; the intensity of this transition increases with increasing dopant concentration. The pure precursor phthalocyanines are diamagnetic while the doped products all contain delocalized unpaired spins. Product spin densities at room temperature, measured both by e.s.r. and magnetic susceptibility methods, are between 0.005 and 0.18 spins per dopant molecule. Spin-signal temperature dependences identified include Pauli-like behaviour with a Curie tail, and antiferromagnetic behaviour. X-Ray photoelectron spectra of doped products are consistent with delocalised positive charges (holes) on the phthalocyanine rings. The fluorine and boron or phosphorus core-level signals from the dopant anions are always weaker than expected from the stoicheiometry of the doped product. These weak signals are believed to be associated with the anion being located inside channels created by surrounding phthalocyanines.