手性金属有机膦酸化合物研究- - 从分子手性到宏观螺旋

Chirality is a widespread phenomenon in nature, from the spiral arms of the galaxy to biological macromolecules in life, such as proteins, polysaccharides, nucleic acids and enzymes. Chirality can be viewed as the most remarkable sign of nature. A challenging issue is how to achieve the chiral amplification from the molecular level to morphology. Such studies will not only contribute to further understanding of the origin of the chirality, but also have great significance in the applications of such materials in chiral recognition and separation, asymmetric catalysis, and chiral functional materials. In this project, we shall focus on the syntheses and characterization of homochiral or enantioenriched metal phosphonates by using chiral, racemic or asymmetrical phosphonate ligands. Moreover, the reaction conditions will be carefully adjusted in order to tune the weak interactions between the chiral molecules. Finally chiral amplification from molecule to morphology will be achieved under suitable conditions with the formation of homochiral superhelices of metal phosphonates. The chiral recognition and separation properties as well as the optical and magnetic properties of both the crystals and superhelices will be investigated in detail. Similar work has never been reported before in the literature.

手性是自然界普遍存在的现象，从星系旋臂到生命体中的生物大分子如蛋白质、多糖、核酸和酶等，手性可以说是自然界最显著的标志。如何将手性从分子层次放大到宏观聚集体，是一个极具挑战的课题。相关研究不仅有助于进一步认识手性的起源，而且对手性物质在手性识别和分离、不对称催化、手性功能材料等方面的应用具有十分重要的意义。本项目将通过设计合成单一手性的、外消旋的或不对称的有机膦酸配体，组装出单一手性的或对映体过量的金属有机膦酸化合物，进一步通过改变反应条件调控手性分子之间的弱相互作用，使分子手性得以传递和放大，最终得到手性宏观螺旋体，深入研究手性螺旋体对有机小分子的手性识别和分离作用，研究手性金属有机膦酸螺旋体与手性晶体的光、磁性质并比较它们的差别。类似工作在国内外尚未见报道。

手性是自然界普遍存在的现象，如何将手性从分子层次放大到宏观聚集体，是一个极具挑战的课题。相关研究不仅有助于进一步认识手性的起源，而且对手性物质在手性识别和分离、不对称催化、手性功能材料等方面的应用具有十分重要的意义。本项目通过设计合成单一手性的、外消旋的或不对称的有机膦酸配体，组装出一系列单一手性的或对映体过量的新颖金属有机膦酸化合物，部分化合物显示有趣的磁性质或其它性质。进一步选择手性1-苯乙基胺基甲基膦酸作为配体与硝酸铽反应，通过pH调控手性分子之间的弱相互作用，成功得到具有相同组成和结构的单一手性晶态和宏观螺旋材料，结合实验和理论模拟深入研究了螺旋形成的内在机理。就我们所知，这种通过pH调控使配位聚合物的分子手性得以传递和放大，并最终得到手性宏观螺旋体的方法尚未见国内外报道。