Annulated Dinuclear Metal-Free and Zn(II) Phthalocyanines: Photophysical Studies and Quantum Mechanical Calculations

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• 作者：Christian Litwinski ; Iné ; s Corral ; Eugeny A. Ermilov ; Sebastian Tannert ; Dmitri Fix ; Sergey Makarov ; Olga Suvorova ; Leticia Gonzá ; lez ; Dieter Wö ; hrle ; Beate Rö ; der
• 刊名：Journal of Physical Chemistry B
• 出版年：2008
• 出版时间：July 24, 2008
• 年：2008
• 卷：112
• 期：29
• 页码：8466-8476
• 全文大小：425K
• 年卷期：v.112,no.29(July 24, 2008)
• ISSN：1520-5207

文摘

The results of steady-state and time-resolved absorption and fluorescence experiments as well as quantum mechanical density functional theory (DFT) calculations of metal-free and Zn(II) mononuclear and dinuclear (sharing a common benzene ring) phthalocyanines are presented. A detailed comparison between measured and calculated absorption spectra of all compounds is done, showing a good agreement between theory and experiment. The NH tautomerization for phthalocyanines with an extended π-electron system was shown for the first time at room temperature. The photophysical properties of all possible NH tautomers of metal-free dinuclear Pc have been fully characterized. In the first tautomer, Pc^∥, both pairs of hydrogen atoms are parallel to the connection line of two Pc units. The maximum of the lowest-energy Q absorption band, λ_abs, in Pc^∥ is located at 832 nm, whereas the spectral position of the fluorescence maximum lies at λ_fl = 837 nm. The second NH tautomer, Pc^⊥ (λ_abs = 853 nm, λ_fl = 860 nm), presents the two pairs of hydrogen atoms perpendicularly orientated to the covalent axis, and the third one, Pc^mix (λ_abs = 864 nm, λ_fl = 872 nm), contributing in a minor extend to the absorption and fluorescence spectra of the metal-free dinuclear phthalocyanine, has one perpendicular and one parallel pair of hydrogen atoms. Obviously, only one configuration exists in the case of the Zn(II)-containing dinuclear phthalocyanine (λ_abs = 845 nm, λ_fl = 852 nm).