Hamza Jam Riyan, Sharma Jatan K, Karr Paul A, van der Est Art, D'Souza Francis, Poddutoori Prashanth K
Department of Chemistry & Biochemistry, University of Minnesota Duluth, Duluth, Minnesota 55812, United States.
Department of Chemistry, University of North Texas, Denton, Texas 76203-5017, United States.
J Am Chem Soc. 2024 Sep 18;146(37):25403-25408. doi: 10.1021/jacs.4c06674. Epub 2024 Sep 9.
Porphyrin dyes with strong push-pull type intramolecular charge transfer (ICT) character and broad absorption across the visible spectrum are reported. This combination of properties has been achieved by functionalizing the periphery of hypervalent and highly electron-deficient phosphorus(V) and antimony(V) centered porphyrins with electron-rich triphenylamine (TPA) groups. As a result of the large difference in electronegativity between the porphyrin ring and the peripheral groups, their absorption profiles show several strong charge transfer transitions, which in addition to the porphyrin-centered π → π* transitions, make them panchromatic black dyes with high absorption coefficients between 200 and 800 nm. Time-resolved optical and electron paramagnetic resonance (EPR) studies show that the lowest triplet state also has ICT character and is populated by spin-orbit coupled intersystem crossing.
据报道，卟啉染料具有强推拉型分子内电荷转移（ICT）特性且在可见光谱范围内具有广泛吸收。通过用富电子的三苯胺（TPA）基团对高价且高度缺电子的以磷（V）和锑（V）为中心的卟啉的外围进行功能化，实现了这些特性的组合。由于卟啉环与外围基团之间电负性存在较大差异，它们的吸收光谱显示出几个强电荷转移跃迁，除了以卟啉为中心的π→π*跃迁外，还使它们成为在200至800nm之间具有高吸收系数的全色黑色染料。时间分辨光学和电子顺磁共振（EPR）研究表明，最低三重态也具有ICT特性，并且通过自旋 - 轨道耦合的系间窜越进行填充。
