ABSTRACT
Indolizino[5,6-b]quinoxaline derivatives (1 a and 1 b) with a push-pull structure were prepared to show intramolecular charge-transfer properties. Compounds 1 a and 1 b are strongly fluorescent in aprotic solvents while symmetrical derivatives (2 a and 2 b) were non-fluorescent. The π-expanded α-α linked dimer (10) of indolizino[5,6-b]quinoxaline 1 b was serendipitously obtained to show NIR absorption over 800â nm and the fluorescence edge reached to 1400â nm.
ABSTRACT
Stable 9,9'-anthryl-anthroxyl radicals were synthesized and isolated, and the structures were fully characterized by single crystal X-ray diffraction analysis and ESR measurement. The resonance structure and steric protection of the peripheral positions and the most reactive 9-position of anthracene prolong the half-life of the radical in solution to 11 days.
Subject(s)
Anthracenes/chemistry , Phenols/chemistry , Drug Stability , Free Radicals/chemistry , Half-Life , Models, Molecular , Molecular ConformationABSTRACT
An optically and thermally responsive boron dipyrromethene (BODIPY) dye, namely, meso-2-(9,10-dihydro-9,10-ethanoanthracene-11,12-dione) (DK)-linked, bicyclo[2.2.2]octadiene (BCOD)-fused BODIPY (BCOD-DK), was synthesized. The weakly luminous structure of BCOD-DK can be changed quantitatively to that of the strongly fluorescent BODIPY BCOD-Ant by optical excitation at the DK unit, which induces double decarbonylation of the DK unit to give an anthracene unit. The solvent effect on the fluorescence properties of BCOD-DK suggests that the dramatic change in fluorescence intensity is controlled by intramolecular electron transfer from the BODIPY moiety to the meso-DK substituent. BCOD-DK is converted to meso-DK benzene-fused BODIPY (Benzo-DK) by heating at 220 °C with 64-70â nm redshift of absorption and fluorescence peaks without changing the fluorescence quantum yield of ΦF =0.08 in dichloromethane. Benzo-DK can be converted to strongly fluorescent meso-anthracene benzene-fused BODIPY Benzo-Ant by optical excitation. Thus, BCOD-DK can show four different optical performances simply by irradiation and heating, and hence may be applicable for optical data storage and security data encryption.
ABSTRACT
P-n junction solar cells based on anthradithiophene (ADT) as a p-type semiconductor were fabricated by using the photoprecursor method in which an α-diketone-type precursor was spin-coated and then transformed to ADT in situ by photoirradiation. Combination with PC71BM as an n-layer material led to 1.54% photoconversion efficiency.
ABSTRACT
The non-luminous precursor, 2-(1-pyrenyl)-9,10-dihydro-9,10-ethanoanthracene-11,12-dione, was photochemically converted to highly-fluorescent 2-(1-pyrenyl)anthracene quantitatively in solution and in the PMMA film and the fluorescence quantum yield of the acene in benzonitrile was as high as 0.99.
Subject(s)
Anthracenes/chemistry , Fluorescent Dyes/chemistry , Pyrenes/chemistry , Anthraquinones/chemistry , Anthraquinones/radiation effects , Light , Photochemical Processes , Spectrophotometry, UltravioletABSTRACT
Hole mobility was evaluated by top-contact bottom gate field effect transistor and time resolved microwave conductivity measurements in 2,6-dithienylanthracene and hexyl-substituted 2,6-dithienylanthracene films prepared by spin-coating of their α-diketone precursors followed by photoirradiation, revealing enough high potentials for semiconducting films with charge carrier mobilities of 0.8-0.9 cm(2) V(-1) s(-1) in the photo-irradiated films.