含磷羧酸分子基材料的设计合成及其气敏性能研究

In the project, we aim to synthesize a series of high stable porous metal-organic frameworkes coordination polymers fabricated by metal ions (Zn2+、Cd2+、In3+、Ln3+, et. al) and phosphor-aromatic carboxylic acid ligands with different rigid and length, which can be self-assembled under various synthetical condition. Their selecting adsorption and response for guest molecules and gas sensitivities as a novel class of porous molular materials will be also investigated. Porous metal-organic frameworks (MOFs) coordination polymers are as a novel class of molecule-based materials. They are known for inorganic-organic hybrid with regular structures, tunable pore size, extraordinarily high surface areas, and adjustable internal surface properties, et. al. The outstanding properties of MOFs provide a unique platform and show an important advantage over other candidate for selecting adsorption and response for guest molecules. In this project the title coordination polymers have open porous metal-organic frameworks structures, unsaturated coordinated metal sites and the oxygen atoms from P-O bonds. These active sites are advantageous for adsorption or for recognization of guest molecules, because the open metal sites can give chance to coordinate to some guest molecules,and the different pore size can only admit some suitable guest molecules transit. We will also fabricate porous complexes into MOFs thin films through directed synthetical method by using metal ions and organic ligands self-assembled or by using vacuum evaportion plating on the metal-base surface. Their gas sensitive properties can be studied in the system of gas sensors detection. The porous MOFs with different structures and responsive guest molecules will be studied to understand the relation of MOFs structures and responsive mechanism to different guest molecules. All these works can provide stably academic base and technology for the developing and application of the new class of gas senor materials.

本项目拟通过不同刚性和长度的含磷羧酸配体与金属离子(Zn2+、Cd2+、In3+、Ln3+等)构筑出系列稳定性高的多孔金属－含磷羧酸分子基材料，探索其对小分子的选择性吸附性质，尤其是气敏性能。多孔金属-有机骨架配合物（MOFs）作为一类新型分子基材料，具有无机-有机杂化、结构有序性、可裁剪性和高的比表面积等特点，为客体分子的选择性吸附和响应提供了独特平台。本项目合成MOFs结构中具有不饱和金属配位点和磷氧键等潜在的活性位点，有利于这类分子基材料对客体分子的选择性吸附或识别。在此基础上，拟将良好气敏性能的分子材料通过直接反应沉积或真空蒸镀在金属基质表面上制备MOFs薄膜气敏元件，在气敏测试系统中研究该类配合物材料对不同客体分子的响应，并初步探明其结构与气敏响应机制间的关系，为气敏传感器新材料的开发和应用提供理论基础和技术支持。

本项目获国家自然科学基金 (No. 21271143)资助后，研究小组先合成了八种含磷羧酸配体，并以分子晶体工程学为手段，采用溶液挥发法、溶剂(水)热等合成手段，合成得到系列多孔含磷金属有机框架结构配合物。并对其配合物的合成条件及其结构进行了系统研究，发现金属与有机配体的比率、有机含氮配体的碱性和尺寸大小、阴离子的种类、温度和溶剂的极性等因素对形成金属有机框架结构有重要的影响。同时研究了相关金属-含磷羧酸骨架配合物的结构及其荧光、磁学性能等性质，阐明了这些化合物结构与性质之间的关系。此外,我们通过芴基二羧酸类配体和稀土金属铕金属离子自组装得到两个多孔铕框架结构的配位聚合物，研究其对系列含硝基类爆炸物分子的荧光焠灭情况，结果表明两个多孔铕配合物表现出高灵敏度和高选择性的新型荧光传感材料，这些具有加工成光敏传感器件并应用于爆炸物分子的检测的潜在应用。本项目的研究对理解功能配合物的自组装规律、结构多样性及其在磁性、催化、荧光等研究领域的有益发展和补充，同时也为结构新颖、性能优异的荧光传感器的进一步开发提供可借鉴的新思路。