异金属卟啉配合物的设计合成及性质研究

Particular interest has been devoted to porphyrin-containing systems, since porphyrin derivatives possess abundant photophysical and photochemical properties, such as good chemical stability, large molar absorption coefficient, and long lifetime of the exited states. However, attentions are mainly paid to photosensitizes, molecule-based materials for catalytic transformation has been less reported. With the knowledge of coordination chemistry, our current project use step-by-step synthetic route to prepare highly stable and efficient heteronuclear (such as Zn-Re or Zn-Pt) porphyrin-based complexes, providing new synthetic strategy for solar-driven catalyst. Novel molecule-based would be constructed by modification of a meso-porphyrin with appropriate functional groups. Photoinduced charge/energy transfer and catalytic reactivity could be investigated by many spectroscopic methods, such as fluorescence, UV-vis absorption, electrochemistry, time-solved IR. Structural simulation and orbital analysis could be performed with density functional theory (DFT) and time-dependent density functional theory (TDDFT), and the relation between molecular structure and catalytic property would be explored. The mechanism of photocatalytic reaction (such as the reduction of carbon dioxide) would also be studied by DFT and TDDFT calculations. Through both experimental and theoretical research, we are going to improve the efficiency and selectivity of new photocatalysts. The current project is an interdisiplinary project of chemistry, material science, and energy science. It could provide new ideas and strategies for searching novel molecular materials with photocatalytic properties. We aim to build up the foundation for efficient utilization of solar energy.

本项目基于具有丰富光化学和光物理性质的卟啉单元，运用配位化学的理论与方法，通过逐步合成的实验步骤，制备高效、稳定的共轭桥联异金属(如Zn-Re或Zn-Pt))卟啉配合物，为发展太阳光驱动催化剂提供合成新策略。应用荧光、电化学、紫外可见吸收、时间分辨红外光谱等实验手段，研究其光致电荷/能量转移情况，研究催化反应活性。在实验合成及性质表征的基础上，同时运用密度泛函理论（DFT）及含时密度泛函理论（TDDFT），结合分子模拟的量化方法进行结构模拟和轨道成分分析，探索分子结构与催化性能的关系，揭示光催化反应（如还原二氧化碳）机理，以提高光催化剂的反应效率和选择性。本项目是化学、材料学与能源科学等的学科交叉，将为寻找具有光催化功能的新型分子材料提供新思路，为进一步研究太阳能利用打下坚实基础，具有重要的科研意义和应用前景。

具有独特分子结构的卟啉化合物化学稳定性较好，在可见光区摩尔吸收系数较大，通常具有良好的光谱化学性质，近年来在生化、医药、光催化及材料等领域都得到了广泛的研究。本项目中我们设计了三类具有共轭桥联结构的不对称卟啉新化合物；将有机合成与配位化学结合，通过分步合成的办法依次引入异核中心金属离子，并对新的异金属配合物进行了表征与光谱性质研究；此外通过理论计算分析了分子结构与性质之间的关系，探讨了分子体系内部电子传递的方向，发现了一些影响光谱性质的规律，为将来制备可见光区强吸收的多核卟啉配合物提供了研究基础；同时，这类化合物具有特殊的发光性质，在发光材料的开发上也具有重要的潜在应用价值。项目研究为基于卟啉骨架的新型功能材料的深入研究和制备提供新思路。