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11.
Simokaitiene J Stanislovaityte E Grazulevicius JV Jankauskas V Gu R Dehaen W Hung YC Hsu CP 《The Journal of organic chemistry》2012,77(11):4924-4931
The synthesis and full characterization of new derivatives of indolo[3,2-b]carbazole with differently substituted phenyl groups at nitrogen atoms is reported. Comparative study on their thermal, optical electrochemical, and photoelectrical properties is presented. The synthesized compounds are electrochemically stable. Their highest occupied molecular orbital energy values range from -5.14 to -5.07 eV. The electron photoemission spectra of the films of synthesized materials revealed the ionization potentials of 5.31-5.47 eV. Hole drift mobility of the amorphous film of 5,11-bis(3-methoxyphenyl)-6-pentyl-5,11-dihydroindolo[3,2-b]carbazole exceed 10(-3) cm(2)/V·s at high electric fields, as it was established by xerographic time-of-flight technique. In contrast to diphenylamino substituted derivatives of carbazole, no effect of the position of methoxy groups on the photoelectrical properties was observed for the synthesized methoxyphenyl-substituted derivatives of indolo[3,2-b]carbazole. The indolo[3,2-b]carbazole core has a larger resonance structure that includes 3 phenyl rings, and thus the energy gap of the HOMO and LUMO π orbitals is lower as compared to that of carbazoles. With a larger energy difference between the phenyl substituents and the core moiety, the indolo[3,2-b]carbazole derivatives studied all have a weaker coupling between the phenyl group and a much weaker dependence of the molecular properties on the position of substituents on the phenyl groups as compared to those observed in substituted carbazoles. 相似文献
12.
Marius Dagys Karolina Haberska Sergey Shleev Thomas Arnebrant Juozas Kulys Tautgirdas Ruzgas 《Electrochemistry communications》2010,12(7):933-935
It was found that homogeneous activity of Trametes hirsuta laccase is considerably diminished in the presence of gold nanoparticles (Au-NPs). Heterogeneous electron transfer studies revealed that Au-NPs facilitate direct electron transfer (DET) between the T1 copper site of the laccase and the surface of Au-NP modified electrodes. DET was characterized by the standard heterogeneous ET constant of 0.5 ± 0.6 s?1 at Au-NPs with an average diameter of 50 nm. As a consequence of this a well pronounced DET based bioelectrocatalytic oxygen reduction with current densities of 5–30 µA cm?2 has been achieved at the laccase–Au-NP modified electrodes. 相似文献
13.
Bioelectrodes employing the conversion of N‐substituted phenothiazine/hexacyanoferrate(II) and N‐substituted phenoxazine/hexacyanoferrate(II) that act as synergistic substrates were built using graphite electrode and recombinant laccase. The response of the bioelectrodes to low reactive substrate (hexacyanoferrate(II)) increases 2.9–97 times in presence of high reactive phenothiazine or phenoxazine mediator. The sensitivity of the bioelectrodes reaches 0.5–14.3 A/M?cm2. To background a scheme of bioelectrodes action the kinetics of laccase‐catalyzed synergistic substrates oxidation was investigated in homogenous solution. A satisfactory agreement of experimentally determined rate constants and calculated using parameters of bioelectrocatalytical system confirms the scheme of bioelectrodes action. 相似文献
14.
Andrzej Swinarew Beata Piekarnik Zbigniew Grobelny Andrzej Stolarzewicz Jurate Simokaitienė Egle Andrikaityte Juozas V. Gražulevičius 《Macromolecular Symposia》2011,308(1):8-11
Summary: The polymerization of (9-carbazolyl)methylthiirane in the presence of cyclic oligo(potassium glycidoxide) as the macroinitiator activated 18-crown-6 leads to polythioether with the molecular masses relatively near to the calculated ones. This polythioether dispersed in a commercially available transparent polymer gives a new blue photoluminescent material. 相似文献
15.
The spectrophotometric method of antioxidants determination using recombinant laccase Polyporus pinsitus (rPpL) and Myceliophthora thermophila (rMtL) was developed. The method includes simultaneous oxidation of the antioxidant and high reactive laccase substrate producing chromophoric radical cation. As laccase substrates ABTS and other high reactive phenoxazine derivatives: 2-phenoxazin-10-yl-ethanol (PET), 3-phenoxazin-10-yl-propane-1-sulfonic acid (PPSA) and 3-phenoxazin-10-yl-propionic acid (PPA) were used. The kinetic data were analysed using a scheme of simultaneous oxidation of the antioxidant and the substrate.In a range of (0.9-7.3) × 10−6 M of Trolox the measurings recovered 91 and 99% of the antioxidant if ABTS and both laccases were used. The recovery varied between 82 and 124% if phenoxazine derivatives were used. The antioxidant activity determined in rich with antioxidants food samples, i.e. date-palm, black raisin, golden raisin, skin of red grape, dice of red grape, fitted the literature data. 相似文献
16.
Jolita Ostrauskaite Viktoras Voska Juozas V. Grazulevicius 《Monatshefte für Chemie / Chemical Monthly》2002,133(5):599-607
Summary. A series of new glass-forming hydrazones containing bicarbazolyl units were synthesized starting from 9-(2-(9H-carbazol-9-yl)-cyclobutyl)-9H-carbazole and 9-(6-(9H-carbazol-9-yl)-hexyl)-9H-carbazole, and their thermal properties were studied. The correlation between their inclination to form glasses and their
chemical structures are discussed. The results of a preliminary investigation of the photoelectric properties of amorphous
films of the title compounds are briefly reported. The highest hole drift mobility was observed for 9-(2-(9H-carbazol-9-yl)-cyclobutyl)-9H-carbazole-3-carbaldehyde N,N-diphenylhydrazone; at high electric fields, it approaches 1 · 10−3 cm2/Vs.
Received September 17, 2001. Accepted (revised) October 16, 2001 相似文献
17.
Adis Khetubol Sven Van Snick Egle Stanislovaityte Antti Hassinen Eduardo Coutiño‐González Willem Vanderlinden Yuliar Firdaus Eduard Fron Maarten Vlasselaer Jurate Simokaitiene Steven De Feyter Zeger Hens Juozas V. Grazulevicius Wim Dehaen Mark Van der Auweraer 《Journal of Polymer Science.Polymer Physics》2014,52(7):539-551
Semiconductor quantum dots (QDs) can be used as alternative for transition metal complexes to harvest the nonemissive triplet excitons in organic light‐emitting diodes (OLEDs). In search for a QD‐based OLED material generating blue emission, poly(9‐vinylcarbazole) (PVK) and poly(9‐(2,3‐epoxypropyl) carbazole) (PEPK) are chosen as host for blue‐emitting CdSe/ZnS core/shell QDs. The QDs are encapsulated with 16‐(N‐carbazolyl) hexadecanoic acid (C16), a ligand terminated by a carbazole moiety. As alternative for PVK, PEPK, where the lower molecular weight and less extensive excimer formation could promise a better film formation and more extensive exciton hopping, is explored. The efficiencies of singlet ( ) and triplet ( ) energy transfer to the C16 capped QDs are estimated by combining stationary photoluminescence spectra and fluorescence decays of pristine polymer films with those of polymer films doped with the QDs. At a loading of 30 wt % of the QDs, increases from 12 ± 1% in PVK to 41 ± 2% in PEPK while increases from 37 ± 22% in PVK to 72 ± 48% in PEPK. The investigation of the film morphology by atomic force microscopy confirms that the main factor limiting the triplet transfer efficiency in the PVK matrix is the clustering of the C16 capped QDs. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 539–551 相似文献
18.
Romas?Baronas Juozas?Kulys Karolis?PetrauskasEmail author Julija?Razumiene 《Journal of mathematical chemistry》2011,49(5):995-1010
This paper presents a two-dimensional-in-space mathematical model of an amperometric biosensor based on an enzyme-loaded carbon
nanotubes layer deposited on a perforated membrane. The developed model is based on non-linear non-stationary reaction-diffusion
equations. By changing input parameters the output results are numerically analysed with a special emphasis to the influence
of the geometry and the catalytic activity of the biosensor to its response. The numerical simulation at transition and steady
state conditions was carried out using the finite difference technique. The mathematical model and the numerical solution
were validated by experimental data. The obtained agreement between the simulation results and experimental data was admissible
at different concentrations of the substrate and the mediator. 相似文献
19.
Modelling synergistic action of laccase-based biosensor utilizing simultaneous substrates conversion
Evelina Gaidamauskaitė Romas Baronas Juozas Kulys 《Journal of mathematical chemistry》2011,49(8):1573-1586
The response of a laccase-based amperometric biosensor that acts in a synergistic manner was modelled digitally. A mathematical
model of the biosensor is based on a system of non-linear reaction diffusion equations. The modelling biosensor comprises
three compartments, an enzyme layer, a dialysis membrane and an outer diffusion layer. By changing input parameters the biosensor
action was analysed with a special emphasis to the influence of the species concentrations on the synergy of the simultaneous
substrates conversion. The digital simulation was carried out using the finite difference technique. 相似文献
20.
Tetianec L Bratkovskaja I Kulys J Casaite V Meskys R 《Applied biochemistry and biotechnology》2011,163(3):404-414
The kinetic parameters of carbohydrate oxidation catalyzed by Acinetobacter calcoaceticus pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase (GDH) and Escherichia coli PQQ-dependent aldose sugar dehydrogenase (ASDH) were determined using various electron acceptors. The radical cations of
organic compounds and 2,6-dichlorophenolindophenol are the most reactive with both enzymes in presence of glucose. The reactivity
of dioxygen with ASDH is low; the bimolecular constant k
ox = 660 M−1 s−1, while GDH reactivity with dioxygen is even less. The radical cation of 3-(10H-phenoxazin-10-yl)propionic acid was used as electron acceptor for reduced enzyme in the study of dehydrogenases carbohydrates
specificity. Mono- and disaccharide reactivity with GDH is higher than the reactivity of oligosaccharides. For ASDH, the reactivity
increased with the carbohydrate monomer number increase. The specificity of quinoproteins was compared with specificity of
flavoprotein Microdochium nivale carbohydrate oxidase due to potential enzymes application for lactose oxidation. 相似文献