36677-31-3Relevant articles and documents
Poly(phenylene) and m-Terphenyl as Powerful Protecting Groups for the Preparation of Stable Organic Hydroxides
Wright, Andrew G.,Weissbach, Thomas,Holdcroft, Steven
, p. 4818 - 4821 (2016)
Four benzimidazolium hydroxide compounds, in which the C2-position is attached to a phenyl group possessing hydrogen, bromine, methyl groups, or phenyl groups at the ortho positions, are prepared and investigated for stability in a quantitative alkaline stability test. The differences between the stability of the various protecting groups in caustic solutions are rationalized on the basis of their crystal structures and DFT calculations. The highest stability was observed for the m-terphenyl-protected benzimidazolium, showing a half-life in 3 m NaOD/CD3OD/D2O at 80 °C of 3240 h. A high-molecular-weight polymer analogue of this model compound is prepared that exhibits excellent mechanical properties, high ionic conductivity and ion-exchange capacity, as well as remarkable hydroxide stability in alkaline solutions: only 5 % degradation after 168 h in 2 m KOH at 80 °C. This is the most stable hydroxide-conducting benzimidazolium polymer to date.
Methyl group: A potential building block for edge-to-face interlocking of benzimidazole scaffolds in developing blue light emitting molecular aggregates
Biswas, Bhaskar,Das, Ajit,Kundu, Subhankar,Roy Choudhury, Angshuman,Saha, Subhajit,Singla, Labhini
, (2021/12/27)
Biologically active benzimidazoles are well-known for their therapeutic applications; however, the molecular systems enable their impact in various optical applications. We report a catalyst-free synthesis of methyl-substituted benzimidazole compounds. The benzimidazole derivatives, 2-(p-tolyl)-1H-benzo[d]imidazole (4-Me) and 2-mesityl-1H-benzo[d]imidazole (246-Trime) were synthesized in an oxygenated-aqueous medium through the reaction of ortho-phenylenediamine and methyl-substituted benzaldehydes at 75 °C. The photophysical properties of the benzimidazole scaffolds were investigated in the aqueous medium. 4-Me and 246-Trime derivatives in their aggregated form in solid state displayed a red shift of absorbance and fluorescence intensity relative to their molecular form in the aqueous medium. Spectroscopic, structural and morphological characteristics of the benzimidazole compounds reveal that effective supramolecular interactions are operative to decelerate the intramolecular movements of 4-Me and 246-Trime leading to J-type molecular aggregates. The supramolecular interactions and energy framework analysis of the compounds suggest that strong and short C–H···π interactions with very strong and short intermolecular N···H hydrogen bonding play important role for the development of molecular aggregates and attribute the contribution of dispersive energy to a large extent for the stabilization of 4-Me and 246-Trime molecular aggregates. The para positional effect of the methyl group in the benzimidazole derivatives marks a notable impact on the additional stability of the blue light-emitting molecular aggregates of nano-dimension.
Aerobic {Mo72V30} nanocluster-catalysed heterogeneous one-pot tandem synthesis of benzimidazoles
Khoshyan, Ashkan,Pourtahmasb, Mehrdad,Feizpour, Fahimeh,Jafarpour, Maasoumeh,Rezaeifard, Abdolreza
, (2019/01/04)
A novel heterogeneous one-pot protocol is developed for tandem aerobic synthesis of benzimidazoles through dehydrogenative coupling of primary benzylic alcohols and aromatic diamines co-catalysed by Keplerate-type {Mo72V30} polyoxometalate and N-hydroxyphthalimide (NHPI). The catalytic system also works well for the synthesis of benzimidazoles using benzaldehydes, as commonly used starting materials, in the absence of NHPI. The high activity of the solid nanocluster provides standard conditions avoiding current limitations of oxidation methods including high catalyst loadings. The spectral results and leaching experiments revealed that the nanocapsule preserved its structural integrity after being reused in consecutive runs.
