title: Dipolar rotors orderly aligned in mesoporous fluorinated organosilica architectures.
abstract: New mesoporous covalent frameworks, based on hybrid fluorinated organosilicas, were prepared to realize a periodic architecture of fast molecular rotors containing dynamic dipoles in their structure. The mobile elements, designed on the basis of fluorinated p-divinylbenzene moieties, were integrated into the robust covalent structure through siloxane bonds, and showed not only the rapid dynamics of the aromatic rings (ca. 10(8) Hz at 325 K), as detected by solid-state NMR spectroscopy, but also a dielectric response typical of a fast dipole reorientation under the stimuli of an applied electric field. Furthermore, the mesochannels are open and accessible to diffusing in gas molecules, and rotor mobility could be individually regulated by I2 vapors. The iodine enters the channels of the periodic structure and reacts with the pivotal double bonds of the divinyl-fluoro-phenylene rotors, affecting their motion and the dielectric properties.
authors.affiliation: Department of Materials Science, University of Milano Bicocca, Via R. Cozzi 55, Milano (Italy).
authors.forename: Silvia
authors.initials: S
authors.lastname: Bracco
authors.forename: Mario
authors.initials: M
authors.lastname: Beretta
authors.forename: Alice
authors.initials: A
authors.lastname: Cattaneo
authors.forename: Angiolina
authors.initials: A
authors.lastname: Comotti
authors.forename: Andrea
authors.initials: A
authors.lastname: Falqui
authors.forename: Ke
authors.initials: K
authors.lastname: Zhao
authors.forename: Charles
authors.initials: C
authors.lastname: Rogers
authors.forename: Piero
authors.initials: P
authors.lastname: Sozzani
keywords: NMR spectroscopy; dielectric spectroscopy; hybrid materials; molecular rotors; porous materials