Synthesis and Photoisomerization of Substituted Dibenzofulvene Molecular Rotors.

Autor: Everhart SC; Department of Chemistry and Program in Chemical Physics, University of Nevada, Reno, NV, 89557-0216, USA., Jayasundara UK; Department of Chemistry and Program in Chemical Physics, University of Nevada, Reno, NV, 89557-0216, USA., Kim H; Department of Chemistry and Program in Chemical Physics, University of Nevada, Reno, NV, 89557-0216, USA., Procúpez-Schtirbu R; Department of Chemistry and Program in Chemical Physics, University of Nevada, Reno, NV, 89557-0216, USA.; Coordinador Sección Química General, Escuela de Química, Universidad de Costa Rica, P.O. Box 11501-2060, Costa Rica., Stanbery WA; Department of Chemistry and Program in Chemical Physics, University of Nevada, Reno, NV, 89557-0216, USA., Mishler CH; Department of Chemistry and Program in Chemical Physics, University of Nevada, Reno, NV, 89557-0216, USA., Frost BJ; Department of Chemistry and Program in Chemical Physics, University of Nevada, Reno, NV, 89557-0216, USA., Cline JI; Department of Chemistry and Program in Chemical Physics, University of Nevada, Reno, NV, 89557-0216, USA., Bell TW; Department of Chemistry and Program in Chemical Physics, University of Nevada, Reno, NV, 89557-0216, USA. twb@unr.edu.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2016 Aug 01; Vol. 22 (32), pp. 11291-302. Date of Electronic Publication: 2016 Jul 01.
DOI: 10.1002/chem.201600854
Abstrakt: The synthesis, spectral and structural characterization, and photoisomerization of a family of 2-substituted dibenzofulvene molecular actuators based on (2,2,2-triphenylethylidene)fluorene (TEF) are reported. The 2-substituted species investigated are nitro (NTEF), cyano (CTEF), and iodo (ITEF). X-ray structures of these three compounds and three intermediates were determined to assign alkene configuration and investigate the effects of the 2-substituents on steric gearing. The addition-elimination reaction of Z-9 with trityl anion to form Z-10 proceeded with complete retention of configuration. Rates of photoisomerization were measured at irradiation wavelengths between 266-355 nm in acetonitrile/dioxane solutions at room temperature. Photoisomerization quantum yields (φ) were calculated by means of a mathematical model that accounts for a certain degree of photodecomposition in the cases of CTEF and ITEF. Quantum yields vary significantly with substituent, having maximum values of φ=0.26 for NTEF, 0.39 for CTEF, and 0.50 for ITEF. NTEF is photochemically robust and has a large quantum yield for photoisomerization in the near-UV, making it a particularly promising drive rotor moiety for light-powered molecular devices.
(© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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