title: Solvent-free production of singlet oxygen at the gas-solid interface: visible light activated organic-inorganic hybrid microreactors including new cyanoaromatic photosensitizers.
abstract: We synthesized new cyanoaromatics, benzo[b]triphenylene-9,14-dicarbonitrile (DBTP) 1a and a graftable derivative, 9,14-dicyanobenzo[b]triphenylene-3-carboxylic acid (DBTP-COOH) 1b, easily prepared from commercial reagents. Their photosensitizing properties were investigated. Hybrid porous silica monoliths loaded with encapsulated 1a or grafted 1b were prepared, and their adsorption, spectroscopic and photosensitizing properties, as well as stability, were compared. Solvent-free, efficient oxidation of dimethylsulfide (DMS) was observed at the gas-solid interface under visible light irradiation. Quantum yields of formation of 1O2 inside the porous monoliths are comparable to those of phenalenone. Singlet oxygen lifetimes (approximately 25 micros) were found to be longer in silica monoliths than in usual polar solvents such as methanol or ethanol. This new class of hybrid materials work as porous, transparent, and highly efficient microreactors for oxidation reactions under visible light.
authors.affiliation: CNRS, Université de Pau, IPREM-UMR 5254, Helioparc, 2 rue du President Angot, BP 64053, Pau cedex 9, France. sylvie.lacombe@univ-pau.fr
authors.forename: Sylvie
authors.initials: S
authors.lastname: Lacombe
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Soumillion
authors.forename: Abdelkrim
authors.initials: A
authors.lastname: El Kadib
authors.forename: Thierry
authors.initials: T
authors.lastname: Pigot
authors.forename: Sylvie
authors.initials: S
authors.lastname: Blanc
authors.forename: Ross
authors.initials: R
authors.lastname: Brown
authors.forename: Esther
authors.initials: E
authors.lastname: Oliveros
authors.forename: Christophe
authors.initials: C
authors.lastname: Cantau
authors.forename: Philippe
authors.initials: P
authors.lastname: Saint-Cricq