| Literature DB >> 25689486 |
Silvia Bracco1, Mario Beretta, Alice Cattaneo, Angiolina Comotti, Andrea Falqui, Ke Zhao, Charles Rogers, Piero Sozzani.
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.Entities:
Keywords: NMR spectroscopy; dielectric spectroscopy; hybrid materials; molecular rotors; porous materials
Year: 2015 PMID: 25689486 DOI: 10.1002/anie.201412412
Source DB: PubMed Journal: Angew Chem Int Ed Engl ISSN: 1433-7851 Impact factor: 15.336