FTIR, TGA and DC electrical conductivity studies of phthalocyanine and its complexes

The infrared spectra of phthalocyanine and (Mg+2, Mn+2, Fe+2, Co+2, Zn+2 and Pb+2) phthalocyanines were investigated using FTIR in the range from (4000-400 cm(-1)), as halide discs. The absorption bands of phthalocyanines were compared with the spectral data of phthalocyanine and discussed in relation to its structure. The N-H bands appearing at 3289 and 1006 cm-1 in phthalocyanine disappeared in the phthalocyanines. This is due to the replacement of hydrogen by the metal cation. A new band appeared at 1050 cm(-1) in the metal phthalocyanines, which may be due to the inactive C-N vibration in phthalocyanine activated by the complex formation. Thermogravimetric (TG) analysis curves show that, the main degradation step follows first order kinetics. The minor and major decomposition temperature and also the activation energy of the main degradation step was calculated and discussed. This study focuses on the correlation existing between the structure and the continuous dark conductivity in compacted powder. The temperature dependence of the conductivity was measured in the range (283-450 K) and hints at an activated-like behavior with activation energies depending on the structure. The conduction processes are discussed. (c) 2005 Elsevier B.V. All rights reserved.