Methylammonium Groups at the Solid Walls of Nanometer-Sized, Water-Filled Monolayer Gaps as Binding Sites for a Tetraanionic Porphyrin
作者:Marc Skupin、Guangtao Li、Werner Fudickar、Jörg Zimmermann、Beate Röder、Jürgen-Hinrich Fuhrhop
DOI:10.1021/ja003882a
日期:2001.4.1
the pH to 7 again and addition of more of the anionic porphyrin reclosed the gap.The porphyrin "cover" should be localized at distances of 8-10 and 20 A from the bottom porphyrin by multiple charge interactions. The 8-10 A distance is ideal for studies of photoinduced electron transfer between two porphyrin monomers of different redox potential. Furthermore it was found, that redox-active tyrosine
包含两个仲酰胺功能和缺电子或富电子碳-碳双键的长链硫氢化物在金表面上围绕平躺的八阴离子卟啉自组装。因此获得了具有 2 nm 宽的卟啉基间隙的刚性和反应性表面单层。然后将金电极浸入水中,间隙表面的双键与甲胺反应。通过迈克尔加成或通过用次溴酸盐溴化然后甲胺取代将其加到双键上。只有间隙边界处的双键可被溶解在大量水体积中的甲胺接触并发生反应。刚性膜间隙的壁现在在限定高度的双键位点处含有甲基铵基团。四阳离子卟啉铜 (II) 不能再扩散到间隙中,并且不会淬灭间隙底部的八阴离子卟啉的荧光。另一方面,四阴离子卟啉被铵基团固定。然后,结合的卟啉作为分子覆盖物,在铁氰化物从大量水传输到电极的过程中充当间隙。通过将 pH 值提高到 12 来去除它,其中甲基铵基团被中和成胺。再次将 pH 值降低至 7 并添加更多的阴离子卟啉重新闭合了间隙。卟啉“覆盖物”应通过多重电荷相互作用定位在距底部卟啉 8-10 和 20 埃的距离处。8-10