Visible Light-Mediated Ullmann-Type C–N Coupling Reactions of Carbazole Derivatives and Aryl Iodides
作者:Woo-Jin Yoo、Tatsuhiro Tsukamoto、Shu̅ Kobayashi
DOI:10.1021/acs.orglett.5b01645
日期:2015.7.17
The combined use of an iridium-based photocatalyst and a copper salt under blue light emitting diode irradiation enables the Ullmann-type C–N cross-coupling reaction between carbazole derivatives and aryl iodides to proceed under mild conditions.
Phosphorescent platinum(ii) complexes containing different β-diketonate ligands: synthesis, tunable excited-state properties, and their application in bioimaging
A series of square-planar Pt(II) complexes [Pt(C^N)(O^O)] (1â5) (C^N = 2-phenylpyridine, O^O denotes a series of β-diketonate ligands) is reported. Detailed studies of theoretical calculations, electrochemical and photophysical properties have shown that their excited states can be attributed to the mixing of 3MLCT, 3LLCT and 3LC/3ILCT transitions. For 1, the excited state is dominated by the C^N ligand. The excited states of complexes 2â5, however, are dominated by O^O ligands. Through variation of the β-diketonate ligands, the emission colors of 1â5 can be tuned from blue-green to yellow. Further investigations have revealed that the emission of 4 in the solid state can be attributed to the 3MLCT and 3LLL'CT transitions, which has been confirmed by X-ray diffraction studies as well as theoretical calculations. Moreover, exclusive staining of cytoplasm and low cytotoxicity have been observed for 1â4, which makes them promising candidates as phosphorescent probes for bioimaging.
Solution-state photophysics of N-carbazolyl benzoate esters: dual emission and order of states in twisted push–pull chromophores
作者:Liubov M. Lifshits、Darya S. Budkina、Varun Singh、Sergey M. Matveev、Alexander N. Tarnovsky、Jeremy K. Klosterman
DOI:10.1039/c6cp04619c
日期:——
studied in solution. Dual emission from the locally excited (LE, the lowest-energy singlet excited state of 1Lb nature localized on the carbazole donor) and the highly polarized, intramolecular charge-transfer states of (pre)-twisted type (TICT states) is observed in non-polar and polar solvents. Ultrafast transientspectroscopy reveals that the excitation into the 1Lb LE state is followed by rapid (∼ps)
在溶液中研究了一系列N-咔唑基苯甲酸酯推挽生色团中的逐步光诱导电荷转移。观察到了来自局部激发的双发射(LE,咔唑供体上固有的最低能量的1 L b性质的单重态激发态)和(预)扭曲类型的高极化分子内电荷转移态(TICT态)在非极性和极性溶剂中。超快速瞬态光谱显示,激发到1 L b LE状态后,电荷快速分离(〜ps),进入发射性TICT状态。激发到1 L的咔唑(S 2)上的第二个单重态激发态一个性质的结果在两个子100fs的人口1大号b和TICT状态。