371193-08-7Relevant articles and documents
Functionalized tetrafluorenylethylene-type chromophores: Synthesis, two-photon absorption and effective optical power-limiting properties in the visible-to-near IR region
Lin, Tzu-Chau,Lee, Ying-Hsuan,Huang, Bor-Rong,Tsai, Ming-Yu,Lin, Jhe-Yi
, p. 325 - 333 (2016)
A series of novel multipolar fluorophores based on tetra-substituted olefinic scaffold using functionalized fluorenyl and indenofluorenyl units as the aryl substituents has been synthesized and investigated for their two-photon-related properties in the f
Synthesis and properties of monodisperse oligofluorene-funcfionalized truxenes: Highly fluorescent star-shaped architectures
Kanibolotsky, Alexander L.,Berridge, Rory,Skabara, Peter J.,Perepichka, Igor F.,Bradley, Donal D. C.,Koeberg, Mattijs
, p. 13695 - 13702 (2004)
This paper describes the strategy toward novel monodisperse, well-defined, star-shaped oligofluorenes with a central truxene core and from monofluorene to quaterfluorene arms. Introduction of solubilizing n-hexyl groups at both fluorene and truxene moieties results in highly soluble, intrinsically two-dimensional nanosized macromolecules T1-T4. The radius for the largest oligomer of ca. 3.9 nm represents one of the largest known star-shaped conjugated systems. Cyclic voltammetry experiments reveal reversible or quasi-reversible oxidation and reduction processes (Eox = +0.74 to 0.80 V, Ered = -2.66 to 2.80 eV vs Fc/Fc+), demonstrating excellent electrochemical stability toward both p- and n-doping, while the band gaps of the oligomers are quite high (Egcv = 3.20-3.40 eV). Close band gaps of 3.05-3.29 eV have been estimated from the electron absorption spectra. These star-shaped macromolecules demonstrate good thermal stability (up to 400-420°C) and improved glass transition temperatures with an increase in length of the oligofluorene arms (from Tg = 63°C for T1 to 116°C for T4) and show very efficient blue photoluminescence (λPL = 398-422 nm) in both solution (ΦPL = 70-86%) and solid state (ΦPL = 43-60%). Spectroelectrochemical experiments reveal that compounds T1-T4 are stable electrochromic systems which change their color reversibly from colorless in the neutral state (～340-400 nm) to colored (from red to purple color; ～500-600 nm) in the oxidized state.
Synthesis and fluorescent properties of conjugated copolymers containing maleimide and fluorene units at the main chain
Nakamura, Munetoshi,Yamabuki, Kazuhiro,Oishi, Tsutomu,Onimura, Kenjiro
, p. 4945 - 4956 (2013/11/06)
Yamamoto or Suzuki-Miyaura coupling polymerizations of 2,3-diiodo-N- cyclohexylmaleimide with fluorene derivatives (2,7-dibromo-9,9′- dihexylfluorene and 9,9′-dihexylfluorene-2,7-diboronic acid) were carried out. The number-average molecular weights (Mn) of the resulting copolymers were 2600-3500 by gel permeation chromatography analysis. The fluorescence emission of the alternating copolymer showed the emission maxima at 551 nm in THF. On the other hand, the random copolymers showed the bimodal emission peaks at 418-420 and 555-557 nm region, respectively. The fluorescence peaks of the random copolymers on the long wavelength region (555-557 nm) were attributed to the conjugated neighboring N-cyclohexylmaleimide-9,9′- dihexylfluorene units in the polymer main chain. Furthermore, the copolymers exhibited the fluorescence solvatochromism by the difference of the polarity of solvents. The alternating and random copolymers showed the different fluorescence solvatochromism, and the emission colors are distinguishable by the naked eye, respectively. Copyright
Photophysical, electrochemical, and crystallographic investigation of conjugated fluoreno azomethines and their precursors
Guarin, Sergio Andres Perez,Dufresne, Stephane,Tsang, Derek,Sylla, Assa,Skene
, p. 2801 - 2811 (2008/09/17)
The photophysical investigation of amino- and aldehyde-substituted fluorenes revealed that these compounds are not only highly fluorescent, but dissipation of their singlet excited energy occurs by a combination of nonradiative means involving intersystem crossing (ISC) and internal conversion (IC). Quantification of the triplet state formed by ISC was possible by laser-flash photolysis (LFP). The efficiency by which this manifold was populated varied between 10 and 40% depending on the fluorene substitution. Condensation of these aldehyde and amine precursors yielded conjugated thiopheno azomethines with robust covalent bonds. Fluorescence of the azomethine fluorene derivatives was reduced relative to their precursors while the degree of IC remained unchanged. Deactivation of the singlet excited state occurred predominately by ISC and the resulting triplet state was rapidly and efficiently quenched by energy transfer by the azomethine linkage. Cyclic voltammetry of the fluoreno azomethines showed both oxidation and reduction processes, and the measured redox potentials and the band-gaps are lower than a bisfluorene analogue. The fluoreno azomethine LUMO energy levels are sufficiently low, making them compatible with common cathodes, therefore eliminating the use of an electron-injection layer. The Royal Society of Chemistry 2007.
