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1.
Artigo em Inglês | MEDLINE | ID: mdl-19019723

RESUMO

New photoluminescence oligoazomethines possessing both hole and electron-transporting units in the main chain were synthesized. Triphenylamine (TPA) was used as the electron-donating group, while 4,4'-diaminooctafluorobiphenyl, 4,4'-(hexafluoro-isopropylidene)dianiline, 4-aminophenylsulfone, 4,4'-(4,4'-isopropylidenediphenyl-1,1'diyldioxy)dianiline and 2,5-bis(4-aminophenyl)-1,3,5-oxadiazole were used as the electron-acceptor or as the electron-donating group. The bifunctional oligomers (D-pi-A and D-pi-D) were soluble in some organic solvents such as chloroform, DMA, HMPA, NMP and formed transparent films on glass support. All oligomers exhibit high glass transition temperature in the range of 188-227 degrees C as determined by differential scanning calorimetry (DSC). The photoluminescence (PL) emission maximum peaks of the oligomers in solution are in the range of 459-552 nm (2.70-2.25 eV) corresponding to blue, blue-green or green light. The solvatochromic and protonation behavior of the oligomers in two solvents (DMA, chloroform) were detected. Oligomers protonated with methanesulfonic acid (MSA) are hypsochromically shifted with respect to the PL spectra of the pristine oligomers measured in solution. Relative PL intensity of the oligomers investigated in chloroform solution was found in the range of 0.10-0.50%, while for protonated ones it was detected in the range of 33-50% in relation to 9,10-diphenylanthracene. Blends of the oligoazomethines with poly(methylmethacrylate) (PMMA) (0.1%, w/w) emitted blue light. Thin films were also doped with iodine. Calculated energy gap for the undoped films following the Tauc relation was in the range of 2.46-2.69 eV while for the iodine doped oligomers in the range of 1.76-2.38 eV was found.


Assuntos
Compostos de Anilina/química , Compostos Azo/síntese química , Luminescência , Fenômenos Ópticos , Tiossemicarbazonas/síntese química , Compostos Azo/química , Clorofórmio/química , Iodo/química , Espectroscopia de Ressonância Magnética , Mesilatos/química , Polimetil Metacrilato/química , Prótons , Soluções , Espectrofotometria Ultravioleta , Tiossemicarbazonas/química
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 69(2): 291-303, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17499017

RESUMO

Relationship between structures and properties of new conjugated polyketanils (PKs) with special architectures, synthesized from three diketones, i.e. p-dibenzoylbenzene, dibenzyl, trans-1,2-dibenzoylethylene and 3,8-diamino-6-phenylphenanthridine, was investigated. The photoluminescence (PL) of green, yellow and red emitting light polymers and their blend was studied. These included the effects of excitation wavelength, concentration and film thickness on the PL. Photoluminescence properties of the PKs before and after protonation with 10-Camphorsulfonic acid (CSA) were tested. The structure formation of (PKs)(1)(CSA)(2) complexes are discussed on the basis of FTIR spectroscopy.


Assuntos
Luz , Macrolídeos/química , Fenantridinas/química , DNA/química , Etídio/análogos & derivados , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Peso Molecular , Fotoquímica , Solubilidade , Espectrofotometria , Espectroscopia de Infravermelho com Transformada de Fourier
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