Visible and near-IR spectroscopic and photochemical characterization of substituted metallophthalocyanines
The UV-visible spectra of copper(II) tetracarboxyphthalocyanine (CuTCPc), copper(II) tetrapentyloxycarbonyl- phthalocyanine (CuTPOCPc) and hydroxyaluminium tricarboxymonoamidephthalocyanine (AlTCPc) were studied as a function of concentration in various solvents. Dye aggregation equilibria were inve...
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| Autores principales: | , , |
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| Formato: | JOUR |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_10106030_v72_n2_p153_GabrielaLagorio |
| Aporte de: |
| Sumario: | The UV-visible spectra of copper(II) tetracarboxyphthalocyanine (CuTCPc), copper(II) tetrapentyloxycarbonyl- phthalocyanine (CuTPOCPc) and hydroxyaluminium tricarboxymonoamidephthalocyanine (AlTCPc) were studied as a function of concentration in various solvents. Dye aggregation equilibria were investigated and pure monomet and dimer spectra were obtained. Near-IR absorption maxima for the above compounds and for cobalt(II) dicarboxydiamidephthalocyanine (Co(II)TCPc) and dicyanocobalt(III) dicarboxydiamidephthalocyanine (Co(III)TCPc) were also obtained and their assignment to triplet-multiplet transitions is discussed. The analysis of the monomer and dimer spectra on the basis of exciton theory and results obtained from molecular mechanics computational calculations allows conclusions to be drawn on the monomer and dimer structures and observed differences in aggregation ability to be interpreted. Quantum yields of singlet molecular oxygen photoproduction by monomers and dimers were determined for aluminium and copper dyes by steady state irradiation using diphenylisobenzofuran as singlet oxygen quencher. The lack of activity in dimers, in accordance with the literature available, is interpreted in terms of the vibronic coupling between monomeric units in the dimer (exciton theory). © 1993. |
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