Alvaro Mercedes, Atienzar Pedro, de la Cruz Pilar, Delgado Juan L, Troiani Vincent, Garcia Hermenegildo, Langa Fernando, Palkar Amit, Echegoyen Luis
Instituto de Tecnología Química CSIC-UPV, Universidad Politécnica de Valencia, 46022-Valencia, Spain.
J Am Chem Soc. 2006 May 24;128(20):6626-35. doi: 10.1021/ja057742i.
A soluble, functionalized Py-SWNT has been synthesized and characterized by solution (1)H and (13)C NMR, FT-Raman, and electron microscopy. Experimental data indicate that Py-SWNT has short tubes with pentyl esters at the tips and pyridyl isoxazolino units along the walls. The synthesis of Py-SWNT is based on a 1,3-dipolar cycloaddition of a nitrile oxide on the SWNT walls, similar to 1,3-dipolar cycloadditions that are common for fullerene functionalization. The resulting Py-SWNT forms a complex with a zinc porphyrin (ZnPor) in a way similar to that reported for pyridyl-functionalized [60]-fullerenes. Formation of this metal-ligand complex was firmly established by a detailed electrochemical study. However, in contrast to the behavior observed for the ZnPor/Py-C(60) complex, photochemical excitation of the complex between ZnPor/Py-SWNT does not lead to electron transfer with the generation of charge-separated states. Fluorescence and laser flash studies indicate that the main process is energy transfer from the singlet ZnPor excited state to the Py-SWNT with observation of emission from Py-SWNT. Triplet ZnPor excited-state quenching by Py-SWNT is only observed in polar solvents such as DMF, but not in benzonitrile.
一种可溶性、功能化的吡啶基单壁碳纳米管（Py-SWNT）已被合成，并通过溶液1H和13C核磁共振、傅里叶变换拉曼光谱以及电子显微镜进行了表征。实验数据表明，Py-SWNT具有短管，管端带有戊酯，管壁上有吡啶基异恶唑啉单元。Py-SWNT的合成基于腈氧化物在单壁碳纳米管管壁上的1,3-偶极环加成反应，类似于富勒烯功能化中常见的1,3-偶极环加成反应。所得的Py-SWNT与锌卟啉（ZnPor）形成复合物，其方式类似于报道的吡啶基功能化[60]富勒烯的情况。通过详细的电化学研究，这种金属-配体复合物的形成得到了确凿证实。然而，与ZnPor/Py-C60复合物所观察到的行为相反，ZnPor/Py-SWNT复合物的光化学激发不会导致电子转移并产生电荷分离态。荧光和激光闪光研究表明，主要过程是能量从单线态ZnPor激发态转移到Py-SWNT，并观察到Py-SWNT的发射。仅在极性溶剂如N,N-二甲基甲酰胺（DMF）中观察到Py-SWNT对三线态ZnPor激发态的猝灭，而在苯甲腈中未观察到。
