多孔配位聚合物的吸附机理研究

As a topical research area in chemistry and materials science, porous coordination polymers are diversified, tailorable, and highly ordered periodic structures being beneficial for understanding their structure-property relationship for designing and synthesizing new and better materials. However, researchers are still mainly focusing on the synthesis and characterization of their basic properities. Mechanism studies on the adsorption processes of these materials are still very preliminary. According to these issues, this project will use in situ X-ray single-crystal/powder diffraction and infrared/Raman/fluoresence spectroscopy to elucidate the adsorption site, adsorption sequence, adsorption strength, and the structure and energy alterations of the host framework and guest molecules. Meanwhile, information about the framework energy, adsorption on the outer crystal surface, and difusion and motion of guest molecules will be obtained by computer simulations based on quantum mechanics, molecular mechanics, and molecular dynamics theories, which will give an indepth understanding of the structure-property relationship and adsorption mechanism. Also, based on these knowledge, new porous coordination polymers with unique structures and storage, separation, and sensing properties will be designed and synthesized for making devices for practical applications.

多孔配位聚合物是化学和材料科学研究的热点，其丰富多样、易于调控、高度有序的周期性结构有利于阐明其吸附机理并设计合成性能更好的新材料。但是，目前相关研究还主要集中在新化合物的合成与基本性能表征，对吸附过程的机理研究还比较初步并遇到了很多困难。有鉴于此，本项目将通过原位X射线单晶/粉末衍射结构分析和原位红外/拉曼/荧光光谱分析以获得配位聚合物吸附过程的吸附位点、吸附顺序、吸附强度、主体框架和客体分子各自的结构变化与能量变化信息，同时以量子力学、分子力学和分子动力学对相关过程进行计算机模拟并进一步获得框架能量、晶体外表面吸附和客体扩散与运动等信息，深入阐明相关材料的吸附机理和构效关系。在此基础上，还将根据这些实验测试和理论分析所得到的结果，设计合成一些具有独特结构和吸附储存、分离和传感性能的新型配位聚合物多孔材料，探讨其器件化和实用化。

多孔配位聚合物具有丰富的框架和孔结构，可以对客体分子产生多样化的吸附，从而用于储存、分离、传感等。利用多孔配位聚合物的晶态结构，理论上比较容易研究其吸附机理，但目前相关报道并不多。为此，本项目利用原位晶体学与光谱，以及计算机模拟对多孔配位聚合物的吸附机理进行了深入的研究，并据此设计合成了系列新型多孔配位聚合物，实现了系列高性能的吸附储存、分离、传感功能。例如，将孔表面活性位点排列在合适的位置，实现了甲烷的高密度储存；利用对孔表面和晶体表面形状的调控，实现了对氟利昂的强吸附、晶体内外表面的超疏水性、二氧化碳和乙炔的高选择性分离等性质；在孔表面引入单齿配位羟基、肼等新型活性位点，实现了常压、烟道气、空气等条件下的系列二氧化碳捕获记录；提出了超微孔亲水孔道捕获疏水烷烃分子的策略，实现了乙烯/乙烷的吸附选择性反转，可高效纯化乙烯；再提出控制客体构型反转气体吸附选择性的策略，可在C4烃类混合物中高效纯化丁二烯。本项目成果在Science, Nat. Commun., JACS, Angew. Chem. Int. Ed., Chem. Sci., Adv. Mater., Inorg. Chem., Sci. China Chem., Energy Environ. Sci.,等专业学术期刊发表了39篇标注论文。