Synthesis of Zinc Tetraphenylporphyrin Rigid Rods with a Built-In Dipole

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• 作者：Keyur Chitre ; Alberto Batarseh ; Andrew Kopecky ; Hao Fan ; Hao Tang ; Roger Lalancette ; Robert A. Bartynski ; Elena Galoppini
• 刊名：Journal of Physical Chemistry B
• 出版年：2015
• 出版时间：June 18, 2015
• 年：2015
• 卷：119
• 期：24
• 页码：7522-7530
• 全文大小：384K
• ISSN：1520-5207

文摘

Three Zn(II) tetraphenylporphyrins (ZnTPP) were synthesized to study the influence of a molecular dipole on the energy level alignment of a chromophore bound to a metal oxide semiconductor: ZnTPP-PE(DA)-IpaOMe (1), ZnTPP-PE-IpaOMe (2), and ZnTPP-PE(AD)-IpaOMe (3). Each contained a rigid-rod linker made of a p-phenylene ethynylene (PE) moiety terminated with the methyl ester of an isophthalic acid unit (Ipa). Porphyrins 1 and 3 contained an intramolecular dipole in the central phenyl ring, which was built by introducing electron donor (D, NMe₂) and acceptor (A, NO₂) substituents in para position to each other. In 1 and 3, the relative position of the D and A substituents, and therefore the dipole direction, was reversed. Porphyrin 2, without substituents in the linker, was synthesized for a comparison. The structures of precursors to 1 and 3 and the structure of 1 were determined by single crystal X-ray analysis. Solution UV鈥搗is and steady-state fluorescence spectra of 1鈥?b>3 were identical to each other and exhibited the spectral features typical of the ZnTPP chromophore and their electrochemical properties were also very similar. Methyl esters 1鈥?b>3 were hydrolyzed to the corresponding carboxylic acids for binding to metal oxide semiconductors.