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[Spectral evidences for aggregation of sulfonated naphthalocyanine zinc (II) and cobalt (II)]
1Department of Chemistry, Harbin Normal University, Harbin 150080, China.
Abstract:
When the naphthalocyanines were sulfonated to give sulfonated naphthalocyanine cobalt (II) and sulfonated naphthalocyanine zinc (II), enhanced aggregation tendency was observed. The Q band of the fluorescence emission spectra and electronic absorption spectra for sulfonated naphthalocyanine zinc (II) and sulfonated naphthalocyanine cobalt (II) in the solutions of DMF and ethanol showed that the excimer or the aggregation form coexists with the monomer, that the aggregation form dissociates into its monomer when the excimer releases a photon or the ground aggregation form absorbs a photon, and that mirror symmetry exists between the fluorescence emission spectrum of the excimer and the electronic absorption spectrum of the corresponding ground aggregation form. There is a red shift for the excimer in the fluorescence emission spectrum and a blue shift for the aggregation form in the electronic absorption spectrum of the Q band. The quenching effect in fluorescence emission spectrum is large when the concentration of sulfonated naphthalocyanine cobalt (II) is high.
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