Tanaka Katsuki, Sakamaki Daisuke, Fujiwara Hideki
Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Naka-ku, Sakai-shi, Osaka, 5998531, Japan.
Chemistry. 2021 Mar 1;27(13):4430-4438. doi: 10.1002/chem.202005005. Epub 2021 Feb 3.
5,12-Dihydro-5,12-diazatetracene (DHDAT) dimers with different substitution patterns are synthesized: a symmetric one with a C-C bond between the monomer units (1) and two asymmetric ones with a C-N bond between the monomer units (2 and 3). The DHDAT units are planar in the C-C linked dimer 1 but perpendicularly oriented in the C-N linked dimers 2 and 3 (from X-ray analysis). The electronic ground-state interaction between the two units is large in 1 and small in 2 and 3. The emission behavior of 3 is different from that of other dimers and its monomer; it displays positive solvatochromism, characteristic for electron donor-acceptor molecules, despite its donor-donor type structure. Compound 3 exhibits a unique multi-step thermochromic emission behavior. The emission behavior is attributed to the asymmetric distribution of the HOMO and LUMO of DHDAT.
合成了具有不同取代模式的5,12 - 二氢 - 5,12 - 二氮杂并四苯（DHDAT）二聚体：一种是单体单元之间带有C - C键的对称二聚体（1），以及两种单体单元之间带有C - N键的不对称二聚体（2和3）。根据X射线分析，在C - C连接的二聚体1中DHDAT单元是平面的，但在C - N连接的二聚体2和3中是垂直取向的。两个单元之间的电子基态相互作用在1中较大，而在2和3中较小。3的发射行为与其他二聚体及其单体不同；尽管其结构为供体 - 供体类型，但它表现出正溶剂化显色性，这是电子供体 - 受体分子的特征。化合物3表现出独特的多步热致变色发射行为。这种发射行为归因于DHDAT的最高占据分子轨道（HOMO）和最低未占据分子轨道（LUMO）的不对称分布。
