In six of seven cases, direct anodic oxidation of the ethynyl group of an ethynylphenyl-derivatized free-base porphyrin gave modified glassy carbon electrodes in which the porphyrin was strongly surface-bound, most likely in a perpendicular geometry through covalent attachment of the ethynyl group to a surface carbon atom. The porphyrins each contained an ethynylphenyl group in one meso position and varied in the groups present in the other three meso positions. Electrografted 5,10,15,20-tetrakis(ethynylphenyl)porphyrin, H21, which has ethynyl moieties in all four meso positions, has well-defined surface voltammetry and grows to multilayer levels upon repeated cyclic voltammetry (CV) deposition scans. Multilayering was not observed to the same degree for monoethynylphenyl-substituted porphyrins and became progressively less for porphyrins having groups in the 15-meso position that were more protective against ethynyl radical attack. Clean molecular monolayer-level coverage was observed for 5-ethynylphenyl-10,20-bis(3-methoxyphenyl)-15-hexylporphyrin, H25. Owing to the fact that the ethynyl oxidation potential (1.1 to 1.5 V vs ferrocene) is more positive than that of the second macrocycle oxidation, the longevities and follow-up reactions of the porphyrin dications were also studied by CV, chemical oxidation, and optical spectroscopy in homogeneous solution. The primary follow-up products of the doubly oxidized porphyrins, whether surface-bound or in solution, were pyrrole-protonated species that were easily reduced back to the neutral porphyrin.

中文翻译：

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乙炔基苯基衍生的游离碱卟啉：阳极氧化过程和共价接枝到玻璃碳电极上。

在七种情况中的六种中，乙炔基苯基衍生化的游离碱卟啉的乙炔基的直接阳极氧化产生修饰的玻璃碳电极，其中卟啉被牢固地表面结合，最有可能通过乙炔基的共价连接形成垂直的几何结构表面碳原子。卟啉各自在一个内消旋位置上含有乙炔基苯基，而在其他三个内消旋位置上存在的基团各不相同。电接枝的5,10,15,20-四（乙炔基苯基）卟啉H21，在所有四个内消旋位置均具有乙炔基部分，具有明确的表面伏安法，并在重复循环伏安法（CV）沉积扫描后生长到多层水平。对于单乙炔基苯基取代的卟啉，未观察到相同程度的多层化，对于具有在15-间位位置上的基团更能抵抗乙炔基自由基攻击的卟啉，则逐渐减少。观察到5-乙炔基苯基-10,20-双（3-甲氧基苯基）-15-己基卟啉H25的分子单层清洁级峰。由于乙炔基氧化电位（相对于二茂铁为1.1至1.5 V）比第二个大环氧化更正，因此还通过CV，化学氧化和光学方法研究了卟啉类药物的寿命和后续反应。均相溶液中的光谱。氧化双卟啉的主要后续产物，无论是表面结合的还是溶液中的，