249296-20-6Relevant academic research and scientific papers
Improving the Electropolymerization Properties of Fluorene-Bridged Dicarbazole Monomers through Polyfluoroalkyl Side Chains
Pecnikaj, Ilir,Orlandi, Simonetta,Pozzi, Gianluca,Cappellari, María Victoria,Marzari, Gabriela,Fernández, Luciana,Zensich, Maximiliano Andrés,Hernandez, Laura,Fungo, Fernando
, p. 8732 - 8740 (2019)
The facile functionalization of the fluorene scaffold at the 2,7-positions was utilized to provide access to two soluble carbazole-π-carbazole derivatives CFC-H1 and CFC-F1 featuring fully hydrogenated and polyfluorinated alkyl chains at the 9-position of
One-pot synthesis of benzofluorene fused aromatic hydrocarbons
Dong, Wendan,Hu, Zhun,Wang, Ziqi,Sun, Bing,Zhang, Xueqiong,Zhang, Fang-Lin
supporting information, (2019/11/13)
A new and efficient synthetic approach for the one-pot construction of benzofluorene fused aromatic hydrocarbons was developed via a transient-directing group strategy. The palladium-catalyzed cascade reaction proceeded via consecutive arylation, cyclization and aromatization steps. Moderate to good yields along with broad functional group tolerance were achieved under mild reaction conditions.
Synthesis of new two-photon absorbing fluorene derivatives via Cu-mediated Ullmann condensations
Belfield, Kevin D.,Schafer, Katherine J.,Mourad, Wael,Reinhardt, Bruce A.
, p. 4475 - 4481 (2007/10/03)
The Ullmann amination reaction was utilized to provide access to a number of fluorene analogues from common intermediates, via facile functionalization at positions 2, 7, and 9 of the fluorene ring. Through variation of amine or iodofluorene derivative, analogues bearing substitutents with varying electron-donating and electron-withdrawing ability, e.g., diphenylamino, bis-(4-methoxyphenyl)amine, nitro, and benzothiazole, were synthesized in good yield. The novel fluorene derivatives were fully characterized, including absorption and emission spectra. Didecylation at the 9-position afforded remarkably soluble derivatives. Target compounds 4, 5, and 9 are potentially useful as fluorophores in two-photon fluorescence microscopy. Their UV-vis spectra display desirable absorption in the range of interest suitable for two-photon excitation by near-IR femtosecond lasers. Preliminary measurements of two-photon absorption indicate the derivatives exhibit high two-photon absorptivity, affirming their potential as two-photon fluorophores. For example, using a 1210 nm femtosecond pump beam, diphenylaminobenzothiazolylfluorene 4 exhibited nondegenerate two-photon absorption, with two-photon absorptivity (δ) of ca. 820 x 10-50 cm4 s photon-1 molecule-1 at the femtosecond white light continuum probe wavelength of 615 nm.
Electroactive and luminescent polymers: New fluorene-heterocycle-based hybrids
Tsuie, Barbara,Reddinger, Jerry L.,Sotzing, Gregory A.,Soloducho, Jadwiga,Katritzky, Alan R.,Reynolds, John R.
, p. 2189 - 2200 (2007/10/03)
The synthesis, characterization, and electrochromic properties of copolymers derived from 9,9-dialkyl-2,7-dibromofluorene (18a, alkyl = C10H21; 24, alkyl = Et) and pyrrole, thiophene, 3,4- ethylenedioxythiophene, and furan are described. Two synthetic routes to 9,9- diethyl-2,7-bis(pyrrol-2-yl)fluorene (30) afford product in 30% and 20% yields, respectively. Monomer 30 undergoes electropolymerization to yield electroactive polymer films. The lowest monomer oxidation potential (E(p,m) = 0.4 V vs. Ag/Ag+) is found in tetraethylammonium tosylate (TEATOS)-CH3CN, but film formation is slow. Spectroelectrochemical analysis of poly(30) reveals a band gap at 2.4 eV and upon polymer oxidation, two low energy absorptions peaking at 1.2 and 2.2 eV appear. This phenomenon is attributed to formation of bipolaron bands between the valence and conduction bands. Soluble fluorene-heterocycle polymers 34a-d have been synthesized by the Stille coupling reaction of 18a and 2,5-bis(trimethylstannyl)thiophene (21a), 5,5'-bis(trimethylstannyl)-2,2'-bithiophene (21b), 2,5- bis(trimethylstannyl)-3,4-ethylenedioxythiophene (21c), and 2,5- bis(trimethylstannyl)furan (22), respectively, in high yields. The NMR spectra are consistent with the proposed structures of the polymers 34a-d, and no evidence of ring opening of the furyl unit in 34d is seen in the NMR and IR spectra. The molecular weights of 34a-d are in the range of 8000 g mol-1 with polydispersity indices (PDI) of 2. Polymers 34a-c have band gaps measured at 2.4 eV, while polymer 34d has its gap at 2.6 eV. Polymers 34a-c undergo solution doping with SbCl5 to form new low energy bipolaron bands at the expense of the absorption in the UV-VIS. However, polymer 34d does not oxidatively dope with SbCl5.
