2-a]pyridine (HPIP, 1) and its derivatives are synthesized, and their fluorescence properties are studied. Although all the compounds show faint dual emission (Φ ≈ 0.01), which is assigned to the normal and excited-stateintramolecularprotontransfer (ESIPT) fluorescence in a fluid solution, they generally display efficient ESIPTfluorescence (Φ up to 0.6) in a polymer matrix. The introduction of electron-donating
2-(2'-羟基苯基)咪唑并[1,2- a ]吡啶(HPIP,1)及其衍生物的合成,并对其荧光性质进行了研究。尽管所有化合物均显示出微弱的双重发射(Φ≈0.01),这与流体溶液中的正常和激发态分子内质子转移(ESIPT)荧光有关,但它们通常在化合物溶液中均显示出有效的ESIPT荧光(Φ最高可达0.6)。聚合物基质。给电子基团和吸电子基团引入苯环分别导致ESIPT荧光发射带发生蓝移和红移。另一方面,将这些基团引入咪唑并吡啶部分导致荧光向相反方向移动。分子内质子转移(IPT)状态的从头算量子化学计算的结果与ESIPT荧光能量非常吻合。计算出的最高占据分子轨道(HOMO)和最低未占据分子轨道(LUMO)能级相对于Hammett取代基常数(σ)的图显示了具有不同斜率的良好线性,这可以合理化取代基的作用及其在聚合物上的位置IPT状态。因此,我们开发了一系列HPIP作为新的ESIPT荧光化合物,并证明
Aggregation-induced emission effect on turn-off fluorescent switching of a photochromic diarylethene
applicable for fluorescence imaging including bio-imaging. On the other hand, a new system called “excited state intramolecular proton transfer (ESIPT)” is reported. In the system, absorption and emission bands are largely separated due to the proton transfer, hence it showed strong fluorescence even in the crystalline state. We aimed to construct the photochromic system incorporating the ESIPT mechanism
The development of aryl-substituted 2-phenylimidazo[1,2-a]pyridines (PIP) with various colors of excited-state intramolecular proton transfer (ESIPT) luminescence in the solid state
electron-withdrawing nature of the para-substituent on the aryl group increases. Varying the substitution position is also an effective tuning method, because the ESIPT luminescence wavelength is in the order 6-aryl < 8-aryl < 6,8-diaryl. Although the quantum yields of these compounds are quite low in organic solutions (Φ ∼ 0.01), they generally display a much stronger ESIPT luminescence in the solid state. For all
已经开发了一系列基于2-苯基咪唑并[1,2- a ]吡啶(PIP)的固态发光染料,其显示出从蓝色到红色的多种发光颜色。而2'-甲氧基PIP(2'MeOPIP,10)显示蓝色发光,而2'-羟基PIP(HPIP,1)则在500 nm左右具有大斯托克斯位移的发射,这被称为激发态分子内质子转移(ESIPT) )发光,只需通过Pd催化的交叉偶联反应将芳基引入HPIP即可将其从蓝绿色变为红色。结果表明,ESIPT发光的能量作为的吸电子性质降低对芳基上的-取代基增加。改变取代位置也是一种有效的调整方法,因为ESIPT的发光波长为6-芳基<8-芳基<6,8-二芳基。虽然这些化合物的量子产率是相当低的在有机溶液(Φ〜0.01),但它们通常显示在固态强得多ESIPT发光。对于除9之外具有长C 6的所有化合物-烷基链,稀冷冻基质和固态中相似的发射特性表明,即使通过结晶学证实了HPIP核的π堆积基序和引入的芳基,