Campidelli Stéphane, Deschenaux Robert, Swartz Angela, Rahman G M Aminur, Guldi Dirk M, Milic Dragana, Vázquez Ester, Prato Maurizio
Dipartimento di Scienze Farmaceutiche, Università degli Studi di Trieste, Piazzale Europa 1, 34127 Trieste, Italy.
Photochem Photobiol Sci. 2006 Dec;5(12):1137-41. doi: 10.1039/b610881d. Epub 2006 Oct 5.
We describe the synthesis, characterization and photophysical properties of a fullerene derivative whose structure includes a Zn-porphyrin and a second generation liquid-crystalline (LC) dendrimer. The size of the fullerene and porphyrin units with respect to the size of the LC dendrimer prevents the formation of liquid-crystalline phases. However, this system gives interesting photoinduced electron transfer phenomena. Compound has been investigated by steady state and time resolved fluorescence as well as transient absorption spectroscopy in polar and apolar solvents. We demonstrate that the fluorescence of the porphyrin unit in is quenched compared to the Zn-tetraphenylporphyrin used as reference. Femto- and picosecond transient absorption permit to identify the formation of a radical ion pair while nanosecond experiments allowed the determination of the charge recombination lifetimes.
我们描述了一种富勒烯衍生物的合成、表征及光物理性质，其结构包含一个锌卟啉和第二代液晶（LC）树枝状大分子。富勒烯和卟啉单元的尺寸相对于液晶树枝状大分子的尺寸阻碍了液晶相的形成。然而，该体系呈现出有趣的光致电子转移现象。已通过稳态和时间分辨荧光以及在极性和非极性溶剂中的瞬态吸收光谱对该化合物进行了研究。我们证明，与用作参考的锌四苯基卟啉相比，该卟啉单元的荧光被猝灭。飞秒和皮秒瞬态吸收可用于识别自由基离子对的形成，而纳秒实验则可确定电荷复合寿命。
