合成了一系列水溶性2-(2'-芳基磺酰胺基苯基)苯并咪唑衍生物,其含有连接到荧光团π-系统各个位置的供电子和接受基团,并在水溶液中以0.1 M离子强度表征。测得的p K a用于单取代衍生物的磺酰胺基去质子化的α的范围在6.75和9.33之间,并严格遵循Hammett的自由能关系。在中性水性缓冲液中,所有化合物均经历有效的激发态分子内质子转移(ESIPT),以产生光互变异构体产生的强烈的斯托克斯位移荧光发射。在高pH下使磺酰胺氮去质子化后,ESIPT被中断以产生新的蓝移发射带。峰值吸收和发射能量受取代基的性质及其在荧光团π系统上的连接位置的强烈影响。ESIPT互变异构体的荧光量子产率显示出与观察到的斯托克斯位移显着相关。
Modulation of imine chemistry with intramolecular hydrogen bonding: Effects from ortho-OH to NH
作者:Zelin Feng、Shuaipeng Jia、Hang Chen、Lei You
DOI:10.1016/j.tet.2020.131128
日期:2020.4
validated the existence of NH⋯O intramolecular hydrogen bonds. The formation and exchange of imines were then studied in acetonitrile, and the acidity of OH/NH significantly influenced the thermodynamics and kinetics of imine reactions. Furthermore, the role of OH/NH⋯N hydrogen bonds on imines was elucidated by the shift of aldehyde exchange equilibrium. Finally, the formation of imines was achieved in aqueous
Excited-State Intramolecular Proton Transfer in 2-(2‘-Arylsulfonamidophenyl)benzimidazole Derivatives: The Effect of Donor and Acceptor Substituents
作者:Maged M. Henary、Wu、John Cody、S. Sumalekshmy、Jing Li、Subrata Mandal、Christoph J. Fahrni
DOI:10.1021/jo070433l
日期:2007.6.1
neutral aqueous buffer, all compounds undergo efficient excited-state intramolecular proton transfer (ESIPT) to yield a strongly Stokes-shifted fluorescence emission from the phototautomer. Upon deprotonation of the sulfonamide nitrogen at high pH, ESIPT is interrupted to yield a new, blue-shifted emission band. The peak absorption and emission energies were strongly influenced by the nature of the substituents
合成了一系列水溶性2-(2'-芳基磺酰胺基苯基)苯并咪唑衍生物,其含有连接到荧光团π-系统各个位置的供电子和接受基团,并在水溶液中以0.1 M离子强度表征。测得的p K a用于单取代衍生物的磺酰胺基去质子化的α的范围在6.75和9.33之间,并严格遵循Hammett的自由能关系。在中性水性缓冲液中,所有化合物均经历有效的激发态分子内质子转移(ESIPT),以产生光互变异构体产生的强烈的斯托克斯位移荧光发射。在高pH下使磺酰胺氮去质子化后,ESIPT被中断以产生新的蓝移发射带。峰值吸收和发射能量受取代基的性质及其在荧光团π系统上的连接位置的强烈影响。ESIPT互变异构体的荧光量子产率显示出与观察到的斯托克斯位移显着相关。
Zinc(II)-Selective Ratiometric Fluorescent Sensors Based on Inhibition of Excited-State Intramolecular Proton Transfer
作者:Maged M. Henary、Yonggang Wu、Christoph J. Fahrni
DOI:10.1002/chem.200305299
日期:2004.6.21
proton transfer (ESIPT) with a series of 2-(2'-benzenesulfonamidophenyl)benzimidazole derivatives. In the absence of Zn(II) at neutral pH, the fluorophores undergo ESIPT to yield a highly Stokes' shifted emission from the proton-transfer tautomer. Coordination of Zn(II) inhibits the ESIPT process and yields a significant hypsochromic shift of the fluorescence emission maximum. Whereas the paramagnetic