Synthesis and photophysics of novel biocompatible fluorescent oxocines and azocines in aqueous solution
作者:A. Ulises Acuña、Mónica Álvarez-Pérez、Marta Liras、Pedro B. Coto、Francisco Amat-Guerri
DOI:10.1039/c3cp52228h
日期:——
accompanying monardine ionization which may abolish de-excitation via intersystem crossing. A similar fluorogenic reaction takes place with catecholamines such as dopamine and DOPA, to yield fluorescent azocines 2a and 2b which, depending on pH, may be present as cationic, neutral or anionic species. TDDFT computations of these forms were also carried out to assign the corresponding excitation transitions
不同质子形式的强荧光半缩醛4,9-二羟基-1,2-二氢-4,11a-甲氧羰基[4,5 - b ]苯并呋喃-5(4 H)-(1a,莫纳ardine),氮杂类似物4,9-二羟基-3,4-二氢-1 H -4,11a-甲基苯并呋喃[2,3 - d ]偶氮素-5(2 H)-1(2a,氮莫尼丁)和各自的2-羧基衍生物(1b,2b)已通过实验和量子化学方法进行了研究。莫纳丁和羧莫纳丁分别是水溶液中羟基酪醇或丹酚酸的新型荧光室温反应的主要产物,它们具有独特的光物理性质。接近中性pH(p K a = 7.2)的黄嘌呤从弱发射,吸收紫外线的(382 nm)中性物质切换为吸收VIS(426 nm),发射蓝光(464 nm)的阴离子形式,并具有荧光量子产率φ ˚F = 1和单指数衰减τ ˚F= 2.74 ns。基于时间相关的密度泛函理论(TDDFT)计算,解释了这种从中性到阴离子形式的二元光谱变化,这是由于(i)