19802-70-1Relevant articles and documents
An iminodibenzyl-quinoxaline-iminodibenzyl scaffold as a mechanochromic and dual emitter: donor and bridge effects on optical properties
Pashazadeh, Ramin,Pander, Piotr,Bucinskas, Audrius,Skabara, Peter J.,Dias, Fernando B.,Grazulevicius, Juozas V.
, p. 13857 - 13860 (2018)
The influence of phenyl linkage and donor strength on the photophysical properties of new derivatives of quinoxaline-containing iminodibenzyl and iminostilbene moieties is studied. The donor-acceptor derivatives showed dual thermally activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP) despite a large energy gap between the excited singlet and triplet states (ca. 0.5 eV). This extremely rare observation is explained by the twisted and rigidified structure of the iminodibenzyl moiety.
Quinoxaline and Pyrido[x,y-b]pyrazine-Based Emitters: Tuning Normal Fluorescence to Thermally Activated Delayed Fluorescence and Emitting Color over the Entire Visible-Light Range
Huang, Tingting,Liu, Di,Jiang, Jingyang,Jiang, Wenfeng
, p. 10926 - 10937 (2019)
Quinoxaline (Q), pyrido[2,3-b]pyrazine (PP) and pyrido[3,4-b]pyrazine (iPP) are used as electron acceptors (A) to design a series of D–π–A-type light-emitting materials with different donor (D) groups. By adjusting the molecular torsion angles through changing D from carbazole (Cz) to 10-dimethylacridine (DMAC) or 10H-phenoxazine (PXZ) for a fixed A, the luminescence is tuned from normal fluorescence to thermally activated delayed fluorescence (TADF). By gradually enhancing the intramolecular charge-transfer extent through combining different D and A, the emission color is continuously and regularly tuned from pure blue to orange–red. Organic light-emitting diodes (OLEDs) containing these compounds as doped emitters exhibit bright electroluminescence with emission colors covering the entire visible-light range. An external quantum efficiency (ηext) of 1.2 % with excellent color coordinates of (0.16, 0.07) is obtained for the pure-blue OLED of Q-Cz. High ηext values of 12.9 (35.9) to 16.7 % (51.9 cd A?1) are realized in the green, yellow, and orange–red TADF OLEDs. All PP- and iPP-based TADF emitters exhibit superior efficiency stabilities to that of analogues of Q. This provides a practical strategy to tune the emission color of Q, PP, and iPP derivatives with the same molecular skeletons over the entire visible-light range.
Ultrasound/visible light-mediated synthesis of N-heterocycles using g-C3N4/Cu3TiO4 as sonophotocatalyst
Arunachalapandi, Murugan,Roopan, Selvaraj Mohana
, p. 3363 - 3378 (2021/04/19)
In this investigation, novel g-C3N4/Cu3TiO4 (CNCT) nanocomposite was synthesized by using a simple thermal condensation method. The synthesized CNCT nanocomposite was characterized by X-ray Diffraction, Transmission electron microscopy, Atomic force microscopy, Energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectroscopy, Photoluminescence, Brunauer–Emmett–Telle, Zeta Potential, and Thermogravimetric analysis. The study revealed that the catalysts prepared have high crystalline nature, optical light-absorbing property, high surface area, and stability. The CNCT- nanocomposite was found to be an extraordinary visible light absorbing catalyst for the synthesis of quinoxaline and quinazolinone derivatives, which have important benefits in a variety of drug applications. Quinoxaline and quinazolinones were prepared from anthranilamide, diamines, benzil, and corresponding aldehydes under Ultrasonic/visible light-medium with a notable amount of g-C3N4/Cu3TiO4. The results exhibit good and excellent yields of product derivatives at mild conditions under Ultrasonic/visible light-medium. Ultrasounds always clean the active site catalyst, promoting activity and reusability. Most notably, with preserved reactivities, this heterogeneous g-C3N4/Cu3TiO4 composite can be used atleast 5 times. Furthermore, we examined the reusability of the catalyst under Ultrasonication coupled with Visible light and in the absence of an Ultrasonication medium. Finally, advantages of the method are non-conventional approach, green solvent, reduced reaction duration, mild condition, and reusable catalyst.
Efficient and sustainable Co3O4 nanocages based nickel catalyst: A suitable platform for the synthesis of quinoxaline derivatives
Sharma, Aditi,Dixit, Ranjana,Sharma, Shivani,Dutta, Sriparna,Yadav, Sneha,Arora, Bhavya,Gawande, Manoj B.,Sharma, Rakesh K.
, (2021/03/01)
Engineered nanocages have emerged at the forefront of nanomaterial investigation as they possess tremendous potential to boost key chemical processes owing to their hollow architectures that can help in achieving high reactivity. With an intention to make profitable use of their morphological features guided chemical activity, we developed dispersable Co3O4 nanocages decorated with nickel nanoparticles for accessing a broad spectrum of pharmaceutically and biologically active N-heterocyclic quinoxaline nuclei using α-dicarbonyls and 1,2-diamines as precursor reagents. For designing Co3O4 nanocages, we employed a simple and scalable method involving Kirkendall effect in which thermal decomposition of Co3[Co(CN)6]2 was carried out thereafter, nanocages were loaded with Ni nanoparticles to obtain the final Ni@Co3O4 catalyst. Results revealed that Ni@Co3O4 catalyst possesses immense potential to accelerate condensation of diamines and di-carbonyls in absence of any additives under mild reaction conditions. The superior catalytic efficiency has been attributed to the hollow architecture of the nanocatalyst comprising of abundant catalytic sites. This protocol exhibits several remarkable attributes such as mild reaction conditions outstanding functional group tolerance, high yield, immense durability and reusability for six subsequent runs.
