Supramolecular Chemistry Composed of Porphyrins and Cyclodextrins

1)卟啉全甲基化环糊精包合物：我们发现一些水溶性的四芳基卟啉与全O-甲基化β-环糊精（TMe-β-CD）形成了非常稳定的1：2包合物。在水溶液中，即使当主体和客体的浓度为10-6 M时，也能定量地形成配合物。2）卟啉-TMe-β-CD复合物的形成机理：研究了极稳定的卟啉-TMe-β-CD复合物的形成机理。因此，明确了TMe-β-CD可以根据客体的形状改变其形状，导致如在生物系统中发现的“诱导配合型络合”。通过诱导拟合型包合实现了主体和客体之间的最佳货车范德华接触。3）杂卟啉阵列的形成：通过 关于我们 将所得结果应用于水溶性卟啉与TMe-β-CD的络合反应。骨架是四苯基卟啉，其外周苯基的对位通过全-O-甲基化的β-环糊精部分连接。这种卟啉-环糊精偶联物只需与另一种卟啉溶液混合即可形成杂卟啉阵列。4）Met-Myogbbin模型：阴离子卟啉的Fe（III）配合物（Fe（III）TPPS）与TMe-β-CD形成了非常稳定的1：2包合物。这样的复合物可以作为高铁肌红蛋白模型，其Fe（III）中心结合到水介质中的各种阴离子。在水溶液中，由于没有TMe-β-CD存在，Fe（III）TPPS不与阴离子结合，因此TMe-β-CD在生物体系中具有类似蛋白质的功能。Fe（III）TPPS/FMe-β-CD配合物对阴离子的结合具有很高的选择性，即N3-选择性地与配合物结合。亲水性、碱性和阴离子的形状是决定阴离子结合的Fe（III）TPPS/TMe-β-CD复合物的稳定性的因素。5）肌红蛋白模型和可逆O2结合：通过Fe（III）TPPS和全-O-甲基化的β-环糊精二聚体构建高铁肌红蛋白模型，其中两个环糊精部分通过含有吡啶部分作为近端碱基的桥连接。我们称这样的模型为“met-hemoCD”。Met-hemoCD被连二亚硫酸盐还原以形成hemoCD（Fe（II）TPPS/环糊精二聚体），其可逆地结合分子氧。在pH6.0的磷酸盐缓冲液中，氧合血红素CD的半衰期为30 h。确定分子氧亲和力为17托。HemoCD显示与肌红蛋白相似的功能。本系统是在水溶液中工作的肌红蛋白或血红蛋白模型的第一个例子。少

1) Porphyrin Permethylated Cyclodextrin Complexes : We found that some water-soluble tetraarylporphyrins form extremely stable 1:2 inclusion complexes with per-O-methylated β-cyclodextrin (TMe-β-CD). The complexes were formed quantitatively in aqueous solutions even when the concentrations of both host and guest were 10-6 M. The results strongly suggest the possibility of this system to be utilized for preparing various supramolecular systems2) Mechanism for Formation of Porphyrin-TMe-β-CD Complexes : Mechanism for formation of extremely stable porphyrin-TMe-β-CD complexes was studied. As a result, it was clarified that TMe-β-CD can alter its shape according to the shape of a guest resulting in "induced-fit type complexation" as is found in biological systems. The optimum van der Waals contacts between the host and the guest are achieved by the induced-fit type inclusion.3) Formation of Heteroporphyrin Arrays : A very convenient method to prepare heteroporphyrin arrays was developed by … More applying the results on complexation of water-soluble porphyrins and TMe-β-CD. A scaffold is the tetraphenylporphyrin whose para-positions of the peripheral phenyl groups are attached by per-O-methylated β-cyclodextrin moieties. Such a porphyrin-cyclodextrin conjugate can form heteroporphyrin array just by mixing with another porphyrin solution. Very efficient energy transfer from zinc complex of water-soluble anionic porphyrin (ZnTPPS) to the free base porphyrin of the conjugate was achieved just by mixing the solution of the conjugate with that of ZnTPPS.4) Met-Myogbbin Model : Fe(III) complex of the anionic porphyrin (Fe(III)TPPS) forms a very stable 1:2 inclusion complex with TMe-β-CD. Such a complex can act as a met-myoglobin model whose Fe(III) center is bound to various anions in aqueous media. The fact that no anion binding to Fe(III)TPPS occurs in aqueous solution in the absence of TMe-β-CD, TMe-β-CD seems to show the function similar to proteins in biological system. High selectivity was found in anion binding to Fe(III)TPPS/FMe-β-CD complex; namely N3- is selectively bound to the complex. Hydrophilicity, basicity, and shape of an anion are the factors to determine the stability of the anion-bound Fe(III)TPPS/TMe-β-CD complex.5) Myogbbin Model and Reversible O2 Binding : A met-myoglobin model was constructed by Fe(III)TPPS and a per-O-methylated β-cyclodextrin dimer where two cyclodextrin moieties were linked with a bridge containing a pyridine moiety as a proximal base. We call such a model "met-hemoCD". Met-hemoCD was reduced by dithionite to form hemoCD (Fe(II)TPPS/cyclodextrin dimer), which bound dioxygen reversibly. The half life time of oxy-hemoCD was 30h in pH 6.0 phosphate buffer. The dioxygen affinity was determined to be 17 Torr. HemoCD shows the functions similar to myoglobin. The present system is the first example of the model of myoglobin or hemoglobin that works in aqueous solution. Less