School of Chemistry, Trinity College Dublin, Dublin 2, Ireland.
J Phys Chem A. 2010 Feb 25;114(7):2464-70. doi: 10.1021/jp909573m.
Complete spectroscopic, structural, and anion-binding properties are reported for a special class of calixphyrins, namely, 5,10-disubstituted porphodimethenes (PDMs). The crystal structure clearly shows that PDMs exhibit nonplanar (distorted) structures with both sp(2)- and sp(3)-hybridized meso carbon centers. We were able to obtain and characterize the diacid form [H(4)(PDM)]X upon addition of several acids to PDMs, where X denotes anions of different acids: HCl, HBr, MeSO(3)H, CF(3)CO(2)H, and HClO(4). We found that the PDM dications generated were more conjugated and thus more stable than their corresponding porphyrins. Their potential to coordinate anions was clearly shown by using (1)H NMR spectroscopy. In addition, we found that when HClO(4) was used to protonate PDMs, the conversion occurs through an intermediate species, which has been assigned to the elusive monoacid derivative on the basis of UV-vis and (1)H NMR experiments.
本文报道了一类特殊的杯吡咯，即 5,10-取代的卟吩二亚甲基（PDM）的完整光谱、结构和阴离子结合特性。晶体结构清楚地表明，PDM 表现出非平面（扭曲）结构，其中包含 sp(2)-和 sp(3)-杂化的中位碳原子。我们能够通过向 PDM 中添加几种酸来获得并表征二酸形式 [H(4)(PDM)]X，其中 X 表示不同酸的阴离子：HCl、HBr、MeSO(3)H、CF(3)CO(2)H 和 HClO(4)。我们发现生成的 PDM 二阳离子更加共轭，因此比它们相应的卟啉更稳定。通过使用 (1)H NMR 光谱清楚地表明了它们与阴离子配位的潜力。此外，我们发现当使用 HClO(4)来质子化 PDM 时，转化通过中间物种发生，该中间物种基于 UV-vis 和 (1)H NMR 实验被分配给难以捉摸的单酸衍生物。
