Function-Structure Relationship in Metal-Organic Frameworks for Mild, Green, and Fast Catalytic C-C Bond Formation was written by Razavi, Sayed Ali Akbar;Morsali, Ali. And the article was included in Inorganic Chemistry in 2019.Formula: C18H10N2 This article mentions the following:
Tunability in chem. functionality is a promising characteristic of metal-organic frameworks (MOFs), which plays an important role in developing and improving the practical applications of MOFs. Here, authors applied this important feature of MOFs to be in line with sustainable development and green chem. principles through the synthesis of MOF-based heterogeneous organocatalysts. According to their green functionalization strategy, some isostructural MOFs (azine decorated TMU-4 with the formula [Zn(OBA)(BPDB)0.5]n·2DMF, azine-Me functionalized TMU-5 with the formula [Zn(OBA)(BPDH)0.5]n·1.5DMF, dihydro-tetrazine decorated TMU-34 with the formula [Zn(OBA)(H2DPT)0.5]n·DMF, and tetrazine functionalized TMU-34(-2H) with the formula [Zn(OBA)(DPT)0.5]n·DMF, where H2OBA = 4,4′-oxybis(benzoic acid), BPDB = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, BPDH = 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene, H2DPT = 3,6-di(pyridin-4-yl)-1,4-dihydro-1,2,4,5-tetrazine, and DPT = 3,6-di(pyridin-4-yl)-1,2,4,5-tetrazine) have been applied for mild, green, and fast Knoevenagel condensation. These frameworks display different Lewis basic catalytic activities owing to their different functionality and function accessibility. Contrary to extensive articles published about Knoevenagel condensation, this study involves the rare examples in Knoevenagel condensation with such mild conditions (room temperature and atm. pressure) and with a green solution (water as the solvent). Due to the combined synergic effects of the Lewis basicity of TMU-frameworks, the amphoteric and hydrogen bond-participating nature of water mols., maximum conversion times are reached just after 30 min (for TMU-5) and 60 min (for TMU-34). Stability and recyclability tests show that TMU-5 and TMU-34 are completely stable in water at reaction conditions and can retain their crystallinity, porosity, and functionality even after five cycles without any specific reduction in their catalytic conversion. Since, in many cases, amine decorated MOFs are applied in Knoevenagel catalyzed condensation, this study is beneficial in providing information about the effects of azine and tetrazine functional groups in reactant activation and the acceleration of Knoevenagel condensation. In this work, according to green chem. principles and sustainable development, we applied some azine and tetrazine TMU-frameworks as basic heterogeneous organocatalysts for mild, green, and fast Knoevenagel condensation in water at room temperature and atm. pressure. In the experiment, the researchers used many compounds, for example, 2-(Anthracen-9-ylmethylene)malononitrile (cas: 55490-87-4Formula: C18H10N2).
2-(Anthracen-9-ylmethylene)malononitrile (cas: 55490-87-4) belongs to nitriles. Nitriles are polar, as indicated by high dipole moments. As liquids, they have high relative permittivities, often in the 30s. In addition, Nitriles can react with alkynes, which leads to an increase in carbon chain length (carbocyanation).Formula: C18H10N2
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts