title: Phototransformation of benzimidazole and thiabendazole inside cucurbit[8]uril.
abstract: The phototransformation of benzimidazole (BZ) and of the benzimidazole pesticide thiabendazole (TBZ) was investigated in aqueous solution in the absence and presence of the supramolecular host cucurbit[8]uril (CB8). ESI-MS and NMR reveal that both compounds form stable 1 : 2 host-guest complexes with CB8 (BZ2@CB8, TBZ2@CB8). The phototransformation of free BZ leads to dehydrodimerization, while for TBZ the photoreactivity leads to BZ, benzimidazole-2-carboximide and 2-acetylbenzimidazole. Inside CB8, BZ undergoes photohydrolysis to form 2-aminoformanilide, while for TBZ2@CB8 additional photoproducts were observed which are pH dependent. At pH 1.2 photolysis of TBZ2@CB8 leads to new red-shifted photoproducts with extended π conjugation.
authors.affiliation: Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University in Prague, Albertov 2030, 128 43 Prague 2, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Smitka
authors.forename: Américo
authors.initials: A
authors.lastname: Lemos
authors.forename: Mintu
authors.initials: M
authors.lastname: Porel
authors.forename: Steffen
authors.initials: S
authors.lastname: Jockusch
authors.forename: Tomás R
authors.initials: TR
authors.lastname: Belderrain
authors.forename: Eva
authors.initials: E
authors.lastname: Tesařová
authors.forename: José P
authors.initials: JP
authors.lastname: Da Silva