937-31-5Relevant articles and documents
Effect of the π-bridge on the light absorption and emission in push-pull coumarins and on their supramolecular organization
Arcos-Ramos, Rafael,Carreón-Castro, María del Pilar,Farfán, Norberto,González-Rodríguez, Edgar,Guzmán-Juárez, Brenda,Maldonado-Domínguez, Mauricio,Miranda-Olvera, Montserrat,Santillan, Rosa
supporting information, (2021/11/08)
A family of eight π-extended push–pull coumarins with cross-conjugated (amide) and directly conjugated (p-phenylene, alkyne, alkene) bridges were synthesized through a convergent strategy. Using an experimentally calibrated computational protocol, their UV–Visible light absorption and emission spectra in solution were investigated. Remarkably, amide-, alkyne- and alkene-bridges undergo comparable vertical excitations. The different nature of these bridges manifests during excited-state relaxation and fluorescence. We predict that these molecules can serve as building blocks for p-type semiconductors with low reorganization energies, below 0.2 eV. Since solid-state self-assembly is crucial for this application, we examined the effect of the π-bridge over the supramolecular organization in this family of compounds to determine if stacking prevails in these π-extended coumarin derivatives. Amide and alkyne spacers allow coplanar conformations which crystallize readily; p-phenylene hinders planarity yet allows facile crystallization; alkene-bridged molecules eluded all crystallization attempts. All the crystals obtained feature dense face-to-face π-stacking with 3.5–3.7 ? interlayer distances, expected to facilitate charge transfer processes in the solid state.
Rip It off: Nitro to Nitroso Reduction by Iron Half-Sandwich Complexes
Korb, Marcus,Hosseini Ghazvini, Seyed Mohammad Bagher,Moggach, Stephen A.,Meunier, Jean-Fran?ois,Bousseksou, Azzedine,Low, Paul J.
, p. 4986 - 4995 (2021/04/06)
Activation of [FeCl(dppe)Cp] (1) by chloride abstraction with Na[BArX4] (X = F, [B(3,5-(CF3)2-C6H3)4]; X = Cl, [B(3,5-Cl2-C6H3)4]) permits reactions with a range of nitro aromatics, RC6H4NO2 (R = halogen, Me, OMe, NO2 or NMe2), to give the cationic iron nitroso complexes [Fe{N(O)-C6H4R}(dppe)Cp][BArX4]) ([3][BArX4]). Similar reactions of 1 and Na[BArX4] with [Fe(NCC6H4NO2)(dppe)Cp][BArX4] gave bimetallic [{Fe(dppe)Cp}2{μ-NCC6H4N(O)}][BArF4]2. However, reactions of 1 and Na[BArX4] with 4-nitrophenol gave the first example of the bench-stable iron half-sandwich phenolate complex [Fe(OC6H4NO2)(dppe)Cp]+ rather than NO2 activation. The formation of complexes [3]+ likely proceeds via the unusual blue bimetallic species [{Fe(dppe)Cp}2{μ,κ2O,O′-O2NAr}]2+. This compound undergoes N-O bond cleavage, resulting in [3]+ and a FeIV=O species, which reacts via an internal C-H activation of the dppe ligand to give [FeIII(κ3O,P,P′-P(2-O-C6H4)(Ph)-C2H4-PPh2)Cp]+. Complexes [3]+ are stable under ambient conditions, are readily purified by column chromatography and can be isolated in up to 50% yield, considering that 0.5 equiv of 1 is required as the oxygen acceptor.
Preparation method of acetenyl aniline
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Paragraph 0079; 0081, (2021/04/14)
The invention discloses a preparation method of acetenyl aniline, wherein the preparation method comprises the following steps: by using nitroethylbenzene as a raw material and MBr-MBrO3-H2SO4 (M=Na or K) as a bromination reagent, carrying out free radical bromination reaction to prepare 1,1-dibromo-1-(nitrophenyl)ethane, carrying out elimination reaction under the action of alkali to obtain nitrophenylacetylene, and finally, carrying out Fe/HCl reduction to obtain acetenyl aniline. The preparation method provided by the invention has the advantages of cheap and easily available raw materials, simple and safe operation, good reaction selectivity, high product yield, less emission of three wastes and the like.
