Two series of donor–acceptor (D–A)-type azobenzene dyes with a tertiary amine as the donor were synthesized, and their photophysical and thermal properties were investigated. Although tertiary amines with the same Hammett constant were used, the properties of the molecules varied considerably depending on the molecular geometry of the tertiary amine. We found that the electron-donating properties could be controlled by the molecular geometry of the donor, as the geometry strongly affected the orientation of the n orbital of the donor relative to the p orbitals of the π-conjugated system of the phenyl ring. When the n orbital was fixed parallel to the p orbitals, the donor exhibited strong electron-donating properties. These results suggest that the molecular geometry should be considered in addition to the primary molecular structure for the design of highly functional materials.

合成了以叔胺为供体的两个系列的供体-受体（D-A）型偶氮苯染料，并对其光物理性质和热性质进行了研究。尽管使用具有相同哈米特常数的叔胺，但是分子的性质根据叔胺的分子几何形状而显着变化。我们发现，电子给体的性质可以通过给体的分子几何形状来控制，因为该几何形状强烈影响给体的n轨道相对于苯环的π共轭体系的p轨道的取向。当n个轨道平行于p个轨道固定时，施主表现出很强的给电子性。