RESUMO
The donor-acceptor design is a classic method of synthesizing new fluorescent molecules. In this study, a series of new fluorescent compounds (1-10) were synthesized based on 2-(3,5-bis(trifluoromethyl)phenyl)-quinazoline acceptor and various amino donors. The fluorescent emissions of 1-10 cover the spectrum from 414 nm to 597 nm in cyclohexane solutions with various amino donors on 4- or 7-positions of quinazoline. Ultimately, compounds 1 and 2 presented the highest photoluminescence quantum yield (QY) over 80%, while compound 10 provided the largest Stokes shift (161 nm) in cyclohexane. Most of them have strong emissions in aggregated states such as in nanoparticles, in powders, in crystals and in films. Mechanochromic properties were observed for compounds 1, 2, 4 and 7. Furthermore, blue OLEDs were fabricated by using compound 2 or 7 as the active layer.
RESUMO
The Cu(II)-catalyzed electrophilic cyclization reaction between o-hydroxyarylenaminones and 3-diazoindolin-2-imines furnished 3-indolyl-4 H-chromen-4-ones in moderate to good yields with a broad substrate scope. Several pyrido[2,3- b:6,5- b']diindoles and one pyrazino[2,3- b:5,6- b']diindole were also obtained as byproducts in some cases and tested for their photophysical properties. Pyrido[2,3- b:6,5- b']diindoles exhibited solvent-dependent emission, while pyrazino[2,3- b:5,6- b']diindole emitted strong luminescence with 25.6% quantum yield in cyclohexane.
RESUMO
Rhodium-catalyzed C-H activation/annulation reactions of ketenimines with N-methoxybenzamides furnished 3-aminoisoindolin-1-ones and 3-(diarylmethylene)isoindolin-1-ones. The synthesized 3-(diarylmethylene)isoindolin-1-ones exhibited aggregation induced emissions in aqueous tetrahydrofuran solution and strong green-yellow emissions in solids.
RESUMO
Potassium carbonate-promoted coupling reactions between 3-diazoindolin-2-imines and nucleophiles were tested. By respectively applying 2-naphthalenols and 2-arylacetates as nucleophiles, 3-azoindoles and 3-hydrazonoindolin-2-imines were obtained in excellent yields. Moreover, 3-azoindol-2-amines could be used as NNO pincer ligands for boron and resulted in the formation of hexacycleborofluorides with their absorption around 580 nm in dichloromethane.
RESUMO
Copper-catalyzed cascade synthesis of 2-aryl-3-cyanobenzofurans from o-hydroxybenzaldehydes and arylacetonitriles in the presence of copper acetate and sodium methoxide is reported. The synthesized 2-aryl-3-cyanobenzofurans emit bright blue under UV light with a quantum yield up to 88.9%.
RESUMO
An optical probe based on colorimetric and ratiometric as well as chemiluminometric signal outputs is developed for the specific detection of hydrazine. On the basis of a Gabriel-type reaction, hydrazinolysis of a simple probe CF (4-phtalamide-N-(4'-methylcoumarin) naphthalimide) produces both the fluorescence of 7-amino-4-methylcoumarin with the max emission wavelength changed from 480 to 420 nm (along with a color change from yellow to transparent) and the luminol chemiluminescence activated by H2O2 with a max emission wavelength at 450 nm. The experimental detection limit of hydrazine is 3.2 ppb (0.1 µM). Selectivity experiments proved CF has excellent selectivity to hydrazine over other interfering substances. Probe CF was also successfully applied in the vapor hydrazine detection over other interfering volatile analytes. Furthermore, the probe CF loaded thin-layer chromatography (TLC) plate for vapor hydrazine detection limit is 5.4 mg/m(3) which is well below the half lethal dose of hydrazine gas for mice (LC50(mice), 330 mg/m(3)) and National Institute of Occupational Safety and Health's immediately dangerous to life or health limit (NIOSHIDLH, 66 mg/m(3)). With H2O2, only hydrazinolysis product luminol can be lighted at 450 nm, other species have no signal. Probe CF can also be used for the detection of hydrazine in HeLa cells.
Assuntos
Hidrazinas/análise , Animais , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Luminescência , Camundongos , Espectroscopia de Prótons por Ressonância MagnéticaRESUMO
A new probe based on the Gabriel mechanism was designed and first used for hydrazine detection with high selectivity against other amines in aqueous solution. Importantly, the probe could be used for gas-state discrimination of hydrazine with different concentrations. Additionally, probe could also be applied for the imaging of hydrazine in living cells.