硅烷化氟硼分子的设计合成及光电性质研究

The major advantage of BODIPY is that its wavelength, luminescence intensity and functionalization can be readily regulated through structural modification. So far, most of the published works have been limited to the carbon-, heteroatom- and halogen-modified systems, in which the optical properties are tuned based on π-π and p-π conjugation. Silicon atom has empty 3d orbitals which provide an effective way to modulate properties of functional molecules through the σ-π conjugation. Furthermore, silicon atom has larger atomic radii and smaller electronegativity than that of carbon atom, the silane-functionalized molecules usually have excellent properties such as good solubility and photothermal stability. Therefore, the silane-based difluoroboron molecules should be exhibited different properties from the classical BODIPY and is a new field worth exploring. In this project, a series of novel silane-functionalized BODIPYs are designed through silyl-, disilanyl (-Si-Si-H, -Si-Si-D, -Si-Si-A) functionalized and silane-bridge (-Si-, -Si-Si-) at the meso-, 2-, 3-, 2,6-, or 3,5-position of BODIPY core. The luminescent properties, photothermal stability and nonlinear optical properties of the molecules in kinds of solvents and aggregated-state will be investigated in detail. TD-DFT calculations will be performed in order to gain further insight into the influence of σ-π conjugation with different electronic effect and silylated-position on the spectroscopic and electronic properties of BODIPY. Some molecules, which have potential application in fluorescent sensor, optoelectronic device as well as novel functional materials with strong optical limiting, should be selected through this research. Basic theory of silylated difluoroboron molecules will be formed through this research, this should facilitate the future rational design of a new generation of silicon-based compounds and materials.

BODIPY的突出优点是通过结构修饰可调控其波长、发光强度及功能等。目前，其结构修饰的研究集中于碳化学、杂原子以及卤素，这些都是基于π-π和p-π共轭效应来调控其光电性质。硅原子具有空的3d轨道，可通过特殊的σ-π超共轭来调制功能分子的性能；同时，硅原子具有较大的原子半径和较小的电负性，硅烷化功能分子通常具有良好的溶解性和光热稳定性等优异性能。因此，硅烷化氟硼分子及其光电性能的精确调控是一个值得探索的新领域。本项目通过在氟硼分子母核的不同位置引入硅烷以及用硅烷桥连等方式构建一系列新型硅烷功能化氟硼分子，研究硅烷化氟硼分子在不同溶剂和聚集状态下的光电性质。结合理论计算，考察具有不同电子效应的σ-π共轭和硅烷化位置对氟硼分子光电性能的影响及规律，筛选出可应用于荧光传感、发光器件和具有高效光限幅效应的新型功能材料，形成硅烷氟硼分子相关的基础理论，为新一代含硅化合物及材料的开发奠定科学基础。

硅原子具有较大的原子半径、较小的电负性和空3d轨道，当硅原子与π电子体系相连时，可通过特殊的σ电子离域，充分扰动π体系的电子结构，从而调制分子功能材料的性能。本项目紧密围绕硅烷化功能分子的设计合成及其性能研究，主要获得了以下成果：①硅硅σ键桥联分子骨架的构建及性质研究，获得了一系列新型硅硅桥联的光功能分子，研究了它们在非线性光学、指纹识别和光控变色等领域的应用；②硅σ*功能分子的构建与性质研究, 获得了一类硅共轭的高效红光氟硼分子，实现了钯催化脱卤脱氢连续反应；实现了共价固定线粒体上的荧光探针及其温度成像；③利用硅元素大位阻效应，实现高激子利用率前提下平衡发光波长，获得了一系列高效近紫外发光器件；④通过氟硼染料的光功能调控，获得了一类具有超级光稳定性的氟硼染料，为无重原子光敏剂的设计提供了新策略；⑤高效构筑了兼具高发光不对称因子和高发光量子效率的近红外有机氟硼分子。上述成果初步形成了硅基光功能分子相关的基础理论和一定的研究特色。项目负责人作为第一或通讯作者在JACS、Angew.Chem.Int.Ed.、Adv.Funct.Mater.、CCS Chem.等期刊上发表论文32篇，申请发明专利3项，培养研究生12名，毕业7名，其中5位赴国内外攻读博士学位。相关论文被JACS、澎湃新闻网等亮点介绍。