Molecular Rotors as Fluorescent Viscosity Sensors: Molecular Design, Polarity Sensitivity, Dipole Moments Changes, Screening Solvents, and Deactivation Channel of the Excited States
DFT/time-dependent DFT calculations, which show that the nonradiative decay channel of the excited FMRs is the rotationabout the dicyanovinyl C=C double bonds in the S1 state, not rotation around C–C single bonds. Extension of the π conjugation of the rotors increases the rotationbarrier around the C=C doublebond in the S1 state (to ca. 50 kJ mol–1 or higher), thus the nonradiative channel is blocked and higher
Synthesis and Properties of 1-(4-Aminophenyl)-2,4-dicyano-3-diethylamino-9,9-diethylfluorenes: Potential Fluorescent Material
作者:Xiao-Hang Chen、Zujin Zhao、Yang Liu、Ping Lu、Yan-Guang Wang
DOI:10.1246/cl.2008.570
日期:2008.6.5
Four new fluorenes bearing two electron donors and two electron acceptors were synthesized and found to emit blue fluorescence in both solution and solid states.
我们合成了四种含有两个电子供体和两个电子受体的新型芴,发现它们在溶液和固体状态下都能发出蓝色荧光。
Oxidative Coupling of Carbazoles: A Substituent-Governed Regioselectivity Profile
(metal-free) recyclable oxidants, such as DDQ or CA/H+, for accessing bicarbazole regioisomers. Differently substituted carbazoles are examined to showcase regioselective discrimination (3,3′- versus 1,3′-bicarbazoles) and preferences based on sterics and electronics in oxidative coupling. Finally, a mechanism that involves the carbazole radical cation has been traced (evidenced) and proposed on the basis of the
在存在有机(无金属)可循环使用的氧化剂(例如DDQ或CA / H +)的情况下,具有各种取代基的咔唑的氧化C-C偶联反应证明了该化合物可与联咔唑区域异构体接触。对不同取代的咔唑进行了研究,以显示区域选择性的区别(3,3'-与1,3'-联咔唑)和在氧化偶联中基于空间和电子学的偏好。最终,已经找到(证明)了涉及咔唑自由基阳离子的机理,并在紫外可见近红外吸收和EPR光谱结果的基础上提出了一种机理。这项研究强调了以有效方式对一系列联咔唑进行战略化学制备的方法。