Jiang Jiaxun, Fang Xianshi, Liu Baozhen, Hu Chuanjiang
Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Suzhou 215123, P. R. China.
Inorg Chem. 2014 Apr 7;53(7):3298-306. doi: 10.1021/ic401949e. Epub 2014 Mar 11.
A novel m-phthalic diamide-linked zinc bisporphyrinate [Zn2-1] has been designed and synthesized. Its chiral crystalline samples have been spontaneously resolved by crystallization. Data for C48H29N5OZn follow: tetragonal, I41, a = 17.809(2) Å, b = 17.809(2) Å, c = 27.080(8) Å, V = 8589 (3) Å(3), Z = 8. X-ray crystallography reveals the two porphyrin subunits are clockwise arranged in the solved structure. Each zinc atom is coordinated by four pyrrole nitrogens and the amide oxygen of the neighboring molecule. Through coordination bonds, it forms a helical chain with P configuration along the c axis. The overall crystal forms an unprecedented chiral bisporphyin coordination polymer. The chirality of the single crystals has been confirmed by CD spectroscopy. UV-vis and NMR spectroscopic studies suggested the molecule aggregates in solution. Such m-phthalic diamide-linked zinc bisporphyrinate shows a strong chiral recognition ability for amino acid ethyl esters. The amplitude value of the induced circular dichroism (ICD) (∼1900 cm(-1) M(-1)) is around 10 times larger than the one observed for the oxalic amide-linked species (Dalton Trans. 2013, 42, 7651-7659). Further studies by (1)H NMR and UV-vis spectroscopies have revealed amino acid esters function as monodentate ligands, and [Zn2-1] interacts with amino acid ethyl esters through coordination and hydrogen bonding interactions. The CD amplitude values have also shown dependence on the bulkiness of the side chain of amino acid esters. A possible chiral recognition mechanism has been proposed.
设计并合成了一种新型间苯二甲酰胺连接的双卟啉锌配合物[Zn2-1]。其手性晶体样品通过结晶自发拆分。C48H29N5OZn的数据如下：四方晶系，I41，a = 17.809(2) Å，b = 17.809(2) Å，c = 27.080(8) Å，V = 8589 (3) Å(3)，Z = 8。X射线晶体学表明，在解析的结构中两个卟啉亚基呈顺时针排列。每个锌原子由四个吡咯氮原子和相邻分子的酰胺氧原子配位。通过配位键，它沿c轴形成具有P构型的螺旋链。整体晶体形成了一种前所未有的手性双卟啉配位聚合物。单晶的手性已通过圆二色光谱法得到证实。紫外可见光谱和核磁共振光谱研究表明该分子在溶液中聚集。这种间苯二甲酰胺连接的双卟啉锌配合物对氨基酸乙酯表现出很强的手性识别能力。诱导圆二色性（ICD）（~1900 cm(-1) M(-1)）的振幅值约为草酸酰胺连接物种所观察到的值的10倍（《道尔顿汇刊》，2013年，42卷，7651 - 7659页）。通过1H NMR和紫外可见光谱进行的进一步研究表明，氨基酸酯作为单齿配体起作用，并且[Zn2-1]通过配位和氢键相互作用与氨基酸乙酯相互作用。CD振幅值也显示出对氨基酸酯侧链体积的依赖性。提出了一种可能的手性识别机制。
