Halide-anion binding by singly and doubly N-confused porphyrins.
Halide-anion binding by singly and doubly N-confused porphyrins.
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DOI：
10.1002/asia.200600182
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发表时间：
2006-12
期刊：
影响因子：
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通讯作者：
H. Maeda;Tatsuki Morimoto;A. Osuka;H. Furuta
中科院分区：
文献类型：
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作者：
H. Maeda;Tatsuki Morimoto;A. Osuka;H. Furuta
研究了N-混乱卟啉（NCP，1）和双N-混乱卟啉（trans-N2 CP（2），cis-N2 CP（3））在CH 2Cl 2中的卤素结合性质。在游离碱形式中，cis-N2 CP（3）对Cl-，Br-，I-的亲和力最高，其结合常数Ka分别为7.8x10（3），1.9x10（3）和5.8x10（2）M（-1）。作为金属配合物，trans-N2 CP 2-Cu对Cl-、Br-和I-的亲和力最高，Ka分别为9.0 × 10（4）、2.7 × 10（4）和1.9 × 10（3）M（-1）。顺式-N2 CP 3-Cu和NCP 1-Cu的相应Ka值分别约为2-Cu的1/10和1/2。通过对一系列三取代氮杂卟啉的密度泛函理论（DFT）计算和互补亲和力测量，发现NCPs与阴离子的有效结合是由于分子中位缺电子的C6 F5基团在高极化的NH基团上形成强氢键，以及理想取向的偶极矩和大的分子极化率.在NCPs的方向和大小的偶极矩被认为是重要的因素在分化的亲和阴离子。
The halide-binding properties of N-confused porphyrin (NCP, 1) and doubly N-confused porphyrins (trans-N2CP (2), cis-N2CP (3)) were examined in CH2Cl2. In the free-base forms, cis-N2CP (3) showed the highest affinity to each anion (Cl-, Br-, I-) with association constants Ka = 7.8x10(3), 1.9x10(3), and 5.8x10(2) M(-1), respectively. As metal complexes, on the other hand, trans-N2CP 2-Cu exhibited the highest affinity to Cl-, Br-, and I- with Ka = 9.0x10(4), 2.7x10(4), and 1.9x10(3) M(-1), respectively. The corresponding Ka values for cis-N2CP 3-Cu and NCP 1-Cu were about 1/10 and 1/2, respectively, of those of 2-Cu. With the help of density functional theory (DFT) calculations and complementary affinity measurements of a series of trisubstituted N-confused porphyrins, the efficient anion binding of NCPs was attributed to strong hydrogen bonding at the highly polarized NH moieties owing to the electron-deficient C6F5 groups at meso positions as well as the ideally oriented dipole moments and large molecular polarizability. The orientation and magnitude of the dipole moments in NCPs were suggested to be important factors in the differentiation of the affinity for anions.