title: Host-guest interactions and orientation of dyes in the one-dimensional channels of zeolite L.
abstract: A combined experimental and modeling study of methylacridine (MeAcr(+)) dye-zeolite L composites unravels the microscopic origin of their functional properties. The anisotropic orientation of the cationic dye inside the ZL channel is unambiguously determined and understood. The most stable orientation of MeAcr(+), which features both its long and short molecular axes nearly perpendicular to the channel axis, is mainly determined by dye-ZL electrostatic interactions but also depends on the cosolvent water. In ZL, MeAcr(+) is not hydrogen bonded to water or ZL framework oxygens and is hydrophobically solvated by water molecules. These findings further support the hypothesis that the cosolvent can importantly influence properties of dye-zeolite composites. Of relevance for a deeper comprehension of the physical chemistry of these hybrids is the observation that trivial energy transfer processes (self-absorption) are often playing a significant role in the optical properties of the composites.
authors.affiliation: Department of Science and High Technology, University of Insubria, and INSTM, Via Lucini 3, I-22100 Como, Italy. fois@fis.unico.it
authors.forename: Ettore
authors.initials: E
authors.lastname: Fois
authors.forename: Gloria
authors.initials: G
authors.lastname: Tabacchi
authors.forename: André
authors.initials: A
authors.lastname: Devaux
authors.forename: Peter
authors.initials: P
authors.lastname: Belser
authors.forename: Dominik
authors.initials: D
authors.lastname: Brühwiler
authors.forename: Gion
authors.initials: G
authors.lastname: Calzaferri