| Autor: |
Ming-Cheng Kuo, Long-An Li, Wei-Nan Yen, Shang-Shih Lo, Cheng-Wei Lee, Chen-Yu Yeh |
| Předmět: |
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| Zdroj: |
Dalton Transactions: An International Journal of Inorganic Chemistry; Mar2007, Vol. 2007 Issue 14, p1433-1439, 7p |
| Abstrakt: |
Sonogashira coupling of zinc 5,10,15,20-tetraethynylporphyrin with various phenyl iodides under mild conditions afforded good yields of the corresponding zinc porphyrins. This method is applicable to a variety of aryl iodides including meso-substituted iodoporphyrin to form a conjugated star-shaped multiporphyrin. The UV-Vis spectra show that peak broadening, red shifts, and changes in the oscillator strength of absorptions increase with the extension of π-conjugation. In the electrochemical measurements, the first oxidation of porphyrins 4–9 occurs at potentials in the range +0.89 to +1.08 V, which are comparable to that of ZnTPP (TPP = tetraphenylporphyrin). The first reduction was observed at potentials from −0.73 to −0.89 V, which is anodically shifted by 390–550 mV as compared to that of ZnTPP, and the second reduction occurs at potentials in the range −1.12 to −1.33 V. The para-substituted tetrakis(phenylethynyl)porphyrins show substituent effects on their redox chemistry and exhibit only slight substituent effects in their emission and absorption maxima. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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