86093-76-7Relevant articles and documents
Air-Sensitive Photoredox Catalysis Performed under Aerobic Conditions in Gel Networks
H?ring, Marleen,Abramov, Alex,Okumura, Keisuke,Ghosh, Indrajit,K?nig, Burkhard,Yanai, Nobuhiro,Kimizuka, Nobuo,Díaz Díaz, David
, p. 7928 - 7938 (2018/06/04)
In this work, we demonstrate that useful C-C bond-forming photoredox catalysis can be performed in air using easily prepared gel networks as reaction media to give similar results as are obtained under inert atmosphere conditions. These reactions are completely inhibited in homogeneous solution in air. However, the supramolecular fibrillar gel networks confine the reactants and block oxygen diffusion, allowing air-sensitive catalytic activity under ambient conditions. We investigate the mechanism of this remarkable protection, focusing on the boundary effect in the self-assembled supramolecular gels that enhances the rates of productive reactions over diffusion-controlled quenching of excited states. Our observations suggest the occurrence of triplet-sensitized chemical reactions in the gel networks within the compartmentalized solvent pools held between the nanofibers. The combination of enhanced viscosity and added interfaces in supramolecular gel media seems to be a key factor in facilitating the reactions under aerobic conditions.
The gas-phase reaction of the CF3 radical with thiophene
Herrera, Olga S.,Nieto, Jorge D.,Lane, Silvia I.,Oexler, Elena V.
, p. 1477 - 1481 (2007/10/03)
The reaction of CF3 radicals, generated by photolysis of CF 3I or hexafluoroacetone with thiophene, was studied in the gas phase at 25°C. At conversion of thiophene less than 20%, monosubstituted CF 3-thiophenes were found as the main reaction products, in addition to CF3H, C2F6, and monosubstituted dihydro-CF3-thiophene, the latter in very low proportion. An isomeric mixture of 2- and 3-CF3-thiophene was obtained in a ratio of about 16, independent of the radical source used (CF3I or hexafluoroacetone) to produce the CF3 radicals. A plausible mechanism that accounts for the observed products is proposed, and the reactivity of thiophene toward the CF3 radical at 25°C was determined as kadd/kc1/2 = 106 ± 4 cm3/2 mol-1/2 s-1/2.
Thiirene formation in the reactions of sulfur atoms with alkynes
Verkoczy, Bela,Sherwood, Alden G.,Safarik, Imre,Strausz, Otto P.
, p. 2268 - 2281 (2007/10/02)
The gas phase reactions of S(1D2) and S(3PJ) atoms with alkynes have been studied by photolyzing COS in the presence of CHCH, CF3CCH, and CF3CCCF3.In the reactions with CHCH, CS2, benzene, and thiophene were formed; with CF3CCH, eight products found with disubstituted thiophenes and trisubstituted benzenes as the major products.In the case of CF3CCCF3, only perfluorotetramethylthiophene was detected at low conversion but at long photolysis several new products were observed.Many of the reaction products characterized here have not been reported before.The formation and distribution of the reaction products could be rationalized by an overall mechanism in which the formation of the highly reactive primary adducts, thiirene and thioformylmethylene, is followed by bimolecular reactions yielding the principal end products.The formation of minor products could be explained by secondary photoisomerizations, secondary photolysis, and by secondary decompositions and the secondary reactions of sulfur atoms with primary products.
