Dielectric Response in the First Silicon Phthalocyanine Network Polymer
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Unlike the well known silicon phthalocyanine polymers, which are only bridged polymers, the first silicon-phthalocyanine network polymer [PcSiCl2] x 6 was prepared from commercially available precursors. Based on previous modeling studies, elemental composition allowed for determination of both the shape and the content of Pc units in the prepared polymer. The two-dimensional network structure was found to offer an extension of the conjugation of the 18-π electron system of the phthalocyanine and facilitate the charge mobility across the material. This was found to enhance the conductivity and dielectric properties of the material, relative to the analogue materials, by supporting the hoping conduction mechanism. Differential scanning calorimetry was used to follow the non-oxidative thermal degradation of the prepared polymeric material. An interesting phenomenon, water effusion, was detected and proved to play a role in the conduction mechanism. Electrical and dielectric measurements were carried out at different frequencies. The polymer has extremely high values of the permittivity ε′ and dielectric loss ε″ at lower frequencies that decrease gradually with increasing frequency. The relaxation peak at lower frequencies showed without doubt that the moisture enhances the conductivity.
KeywordsConductivity Dielectric permittivity Polymers Phthalocyanines Silicon
We are grateful for the financial support of (National Research Centre, Dokki, Giza, Egypt) within the In-house research project number 914-01-02.
- 1.N. McKeown, Capital 9, Science of synthesis, vol. 17 (Thieme Chemistry, Rochdale, 2005)Google Scholar
- 2.C. Leznoff, A. Lever, Phthalocyanines: properties and applications, vol. 1 (VCH Publishers, New York, 1989). references cited thereinGoogle Scholar
- 4.N. Phougat, P. Vasudevan, H.S. Nalwa, Materials and processing, in Chapter 8 in handbook of low and high dielectric constant materials and their applications, vol. 1, ed. by H.S. Nalwa (Academic Press, Hitachi, 1999)Google Scholar
- 16.Wael Darwish, Thesis Dr. rer. Nat., Philipps University, Marburg, Germany. (http://deposit.ddb.de/cgi-bin/dokserv?idn=980818613). Accessed March, 2006
- 17.J.F. Van der Pol, J.W. Zwikker, Recl. Trav. Chim. Pays-Bas 109, 208–215 (1990)Google Scholar
- 27.V. Iliev, A. Mihaylova, J. Photochem. Photobiol. A. Chemistry 149, 23–30 (2002)Google Scholar
- 28.Lukasz Lapok, Thesis-Dr. rer. Nat., Bremen University, Germany, pages 187 and 188 (http://d-nb.info/987483811/34). Accessed September (2006)
- 32.S. Gaspard, M. Verdaguer, R. Viovy, J. Chem. Res. (S), 271 (1979)Google Scholar
- 33.B.D. Berezin, Coordination compounds of porphyrins and phthalocyanines (Wiley, New York, 1981)Google Scholar
- 52.B.N. Achar, P.K. Jayasree, Indian J. Chem. 38A, 1164 (1999)Google Scholar