1455-87-4

Usage

InChI:InChI=1/C8H8N4O3/c1-11(2)5-3-4-6(12(13)14)8-7(5)9-15-10-8/h3-4H,1-2H3

Upstream product

• 5714-17-0 5-chloro-4-nitrobenzo[c]-[1,2,5]oxadiazole 
• 124-40-3 dimethyl amine 
• 506-59-2 N,N-dimethylammonium chloride 
• 10199-89-0 NBD chloride 
• 68-12-2 N,N-dimethyl-formamide 
• 7116-16-7 4-chloro-2,1,3-benzoxadiazole 
• 19155-86-3 5-chlorobenzo[c][1,2,5]oxadiazole 
• 17348-69-5 5-chlorobenzofurazan-1-oxide 
• 1194-66-7 2,6-dichloronitrosobenzene 
• 1635-61-6 5-chloro-2-nitroaniline 

Relevant academic research and scientific papers

Quaternary Piperazine-Substituted Rhodamines with Enhanced Brightness for Super-Resolution Imaging

Insufficient brightness of fluorophores poses a major bottleneck for the advancement of super-resolution microscopes. Despite being widely used, many rhodamine dyes exhibit sub-optimal brightness due to the formation of twisted intramolecular charge transfer (TICT) upon photoexcitation. Herein, we have developed a new class of quaternary piperazine-substituted rhodamines with outstanding quantum yields (φ = 0.93) and superior brightness (? × φ = 8.1 × 104 L·mol-1·cm-1), by utilizing the electronic inductive effect to prevent TICT. We have also successfully deployed these rhodamines in the super-resolution imaging of the microtubules of fixed cells and of the cell membrane and lysosomes of live cells. Finally, we demonstrated that this strategy was generalizable to other families of fluorophores, resulting in substantially increased quantum yields.

Azetidine-Containing Heterospirocycles Enhance the Performance of Fluorophores

Fluorescent dyes are extensively utilized in various fluorescence imaging techniques. However, many existing modification strategies could not balance the performance (such as brightness, photostability, water solubility, and permeability) of fluorophores. Herein we report a general strategy to enhance the performance of donor-acceptor-type fluorophores by introducing azetidine-containing heterospirocycles to the commonly used fluorophore scaffolds. Such a strategy turned out to be a general way to develop high-quality fluorophores.

A General Strategy to Enhance Donor-Acceptor Molecules Using Solvent-Excluding Substituents

While organic donor-acceptor (D-A) molecules are widely employed in multiple areas, the application of more D-A molecules could be limited because of an inherent polarity sensitivity that inhibits photochemical processes. Presented here is a facile chemical modification to attenuate solvent-dependent mechanisms of excited-state quenching through addition of a β-carbonyl-based polar substituent. The results reveal a mechanism wherein the β-carbonyl substituent creates a structural buffer between the donor and the surrounding solvent. Through computational and experimental analyses, it is demonstrated that the β-carbonyl simultaneously attenuates two distinct solvent-dependent quenching mechanisms. Using the β-carbonyl substituent, improvements in the photophysical properties of commonly used D-A fluorophores and their enhanced performance in biological imaging are shown.

An unexpected copper catalyzed 'reduction' of an arylazide to amine through the formation of a nitrene intermediate

Azido nitrobenzoxadiazole (NBD) was observed to undergo a 'reduction' reaction in the absence of an obvious reducing agent, leading to amine formation. In the presence of an excess amount of DMSO, a sulfoxide conjugate was also formed. The ratio of these two products was both temperature- and solvent-dependent, with the addition of water significantly enhancing the ratio of the 'reduction' product. Two intermediates of the azido-NBD reaction in DMSO were trapped and characterized by low-temperature EPR spectroscopy. One was an organic free radical (S=1/2) and another was a triplet nitrene (S=1) species. A mechanism was proposed based on the characterized free radical and triplet intermediates.

Photophysical and dynamic NMR studies on 4-amino-7-nitrobenz-2-oxa-1, 3-diazole derivatives: Elucidation of the nonradiative deactivation pathway

A series of 4-aminonitrobenzoxadiazole (NBD) derivatives in which the amino nitrogen is part of a four- to seven-membered heterocyclic ring and a second series of 4-dialkylamino NBD derivatives with different alkyl chain lengths have been prepared and fully characterized and their photophysical properties investigated in an attempt to find out the nonradiative deactivation pathway of the fluorescent state in these systems. It is observed that the fluorescence properties of the NBD derivatives are highly sensitive to the structure of the amino moiety and the polarity of the surrounding media. It is shown that the nonradiative rate constants for the derivatives with large alkyl groups and large ring systems are considerably higher than those for systems with smaller alkyl groups and smaller ring systems. Dynamic NMR experiments have been carried out to probe the internal motion in the systems. The internal rotation around the bond connecting the amino nitrogen and the NBD ring is found to be rather slow in the ground state. The rate for the internal rotation is found to be the highest for the six-membered ring, and this has been interpreted in terms of the partial double bond character of the C-N bond. The results of the experiments seem to indicate that inversion of the amino nitrogen plays the most important role in determining the fluorescence efficiency of the systems.

Derivatization of Amines with 4-Substituted 7-Nitrobenzofurazans

Electrophilic derivatives of 4-nitro-benzofurazan with different reactivities were used to synthesize 28 new mono- and disubstituted 4-amino-7-nitrobenzofurazans 2b, 2d, 2f-2i, 2l, 2m-2n, 3b-3f, 3h-3j, 4c-4d, 4f-4k, 4m, 4o-4p.A reaction mechanism is proposed on the basis of the differences of the reactivities and a preliminary kinetic examination.The acid character of the N-H-function in monosubstituted compounds is demonstrated by means of spectroscopical investigation of pKa-values.Data from i.r., u.v./vis, and fluorescence studies are offered.