864957-73-3Relevant academic research and scientific papers
Electron Transfer around a Molecular Corner
Schmidt, Hauke C.,Larsen, Christopher B.,Wenger, Oliver S.
, p. 6696 - 6700 (2018)
The distance dependence of electron transfer (ET) is commonly investigated in linear rigid rod-like compounds, but studies of molecular wires with integrated corners imposing 90° angles are very rare. By using spirobifluorene as a key bridging element and by substituting it at different positions, two isomeric series of donor-bridge-acceptor compounds with either nearly linear or angled geometries were obtained. Photoinduced ET in both series is dominated by rapid through-bond hole hopping across oligofluorene bridges over distances of up to 70 ?. Despite considerable conformational flexibility, direct through-space and through-solvent ET is negligible even in the angled series. The independence of the ET rate constant on the total number of fluorene units in the angled series is attributed to a rate-limiting tunneling step through the spirobifluorene corner. This finding is relevant for multidimensional ET systems and grids in which individual molecular wires are interlinked at 90° angles.
Improved synthesis of 2,2′-Dibromo-9,9′-spirobifluorene and its 2,2′-bisdonor-7,7′-bisacceptor-substituted fluorescent derivatives
Chiang, Chih-Long,Shu, Ching-Fong,Chen, Chin-Ti
, p. 3717 - 3720 (2007/10/03)
(Chemical Equation Presented) Pure 2,2′-Dibromo-9,9′- spirobifluorene was synthesized by a method that did not involve troublesome dibromination of 9,9′-spirobifluorene or Sandmeyer reaction of 2,2′-diamino-9,9′-spirobifluorene. A series of donor-acceptor orthogonally substituted 9,9′-spirobifluorene was subsequently prepared showing rich variation of fluorescence in solution and in solid state.
