Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Dalton Trans ; 49(47): 17263-17273, 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33201973

RESUMO

Novel 4,4'-(((2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl)bis(2-methylpropane-2,1-diyl))bis(oxy)) (SUBO) bridged ball-type metallophthalocyanines were synthesized starting from 4,4'-(((2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl)bis(2-methylpropane-2,1-diyl))bis(oxy))diphthalonitrile with convenient metal salts in 2-N,N-dimethylaminoethanol. A new bisphthalonitrile compound was obtained from 2,2'-(2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl)bis(2-methylpropan-1-ol) and 4-nitrophthalonitrile in acetonitrile at reflux temperature in the presence of potassium carbonate as a catalyst. The structural characterization of the compounds was performed by elemental analysis, and infrared, ultraviolet-visible and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopic methods. Nonlinear absorptions of the phthalocyanine complexes were measured using the Z-scan technique with 7 ns pulse duration at a 532 nm wavelength. It is obvious that ball-type copperphthalocyanine has a high nonlinear absorption coefficient and imaginary component of the third-order susceptibility compared to other complexes. Therefore, ball-type copperphthalocyanine can be regarded as a very good candidate for optical limiting applications. Density functional theory was used for geometry optimizations and time-dependent density functional theory calculations of electronic transitions in order to compare with the experimental results. Molecular orbital and nonlinear optical analyses were also performed with density functional theory at the CAM-B3LYP/6-31G(d,p)/LANL2DZ level. The nonlinear optical analyses show that ball-type copperphthalocyanine has significantly better nonlinear optical properties in comparison to a common reference compound, urea.

2.
Dalton Trans ; 42(18): 6633-44, 2013 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-23483046

RESUMO

The synthesis of 4,4'-[6,6'-methylenebis (2-(2-(3,4-dicyanophenoxy)-5-methylbenzyl)-4-methyl-6,1-phenylene)] bis (oxy) diphthalonitrile 1 was achieved starting from 4-nitrophthalonitrile and 6,6'-methylenebis(2-(2-hydroxy-5-methylbenzyl)-4-methylphenol in DMF at 50 °C by the catalysis of K2CO3 under argon. The corresponding dimeric metallophthalocyanines (Zn2Pc2 2 and Co2Pc2 3) were tetramerized in dimethylaminoethanol with the appropriate metal salt. Newly synthesized compounds were characterized by elemental analysis, UV-vis, FT-IR (ATR), MALDI-TOF mass and (1)H-NMR spectroscopy techniques. The electrochemical properties of the complexes were examined by cyclic voltammetry, differential pulse voltammetry, controlled potential coulometry and in situ spectroelectrochemistry in nonaqueous media. The results showed that while there is considerable weak interactions between the two metal phthalocyanine units in dimeric zinc phthalocyanine, these interactions in dimeric cobalt phthalocyanine is remarkable. The catalytic performances of dimeric cobalt phthalocyanine in the reduction of oxygen in a medium similar to the working conditions of the polymer electrolyte membrane fuel-cells were found to be much higher than that of dinuclear zinc phthalocyanine. Solution-processed films of the complexes were utilized as an active semiconducting layer in the fabrication of organic field-effect transistors (OFETs) in the bottom-gate configurations. The output characteristics of the resulting p-type OFET devices were investigated to evaluate the performances such as the field effect mobility (µF). A relatively high field effect mobility of 7.3 × 10(-3) cm(2) V(-1) s(-1) was observed for dimeric cobalt phthalocyanine.

3.
Dalton Trans ; (17): 3175-81, 2009 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-19421619

RESUMO

Heptadecafluorodecyl-substituted cofacial or ball-type bis-metallophthalocyanines (BTMPcs) have been prepared. The redox properties of the complexes and their catalytic activities for oxygen reduction were studied. The occurrence of stepwise one-electron redox processes during the voltammetric measurements in solution suggested the formation of stable mixed-valence species of the complexes, as a result of the intramolecular interactions between two cofacial Pc units. The ball-type Co(ii) complex displayed excellent catalytic activity for oxygen reduction which is probably due to the rigid cofacial structure involving two redox-active metal centers, which are capable of binding O(2). dc and ac conduction properties of BTMPcs [M = Co(ii) and Cu(ii) ]thin films have been investigated in the frequency range of 40 to 10(5) Hz and temperature 290-440 K. The dc results showed an activated conductivity dependence on temperature for all films. The analysis of the obtained data showed that the correlated barrier hopping (CBH) model is the dominant conduction mechanism for electron transport in the films. The gas sensing properties of the films for SO(2) were also investigated over the same temperature range. Although a very high response to SO(2) gas has been obtained for the film of at room temperature, the film of was not sensitive to the same gases.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...