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1.
The synthesis and cationic photopolymerization of different cationically polymerizable monomers containing electroactive groups are reviewed with 98 references. The preparation of various compounds containing electron‐donor or electron‐acceptor moieties and photopolymerizable functional groups is described. After a short discussion of basic principles of cationic polymerization, photoinduced cationic polymerizations of various cationically polymerizable monomers containing both electron‐donor or electron‐acceptor chromophores and the functional groups such as epoxy, vinyl, thiiranyl, oxetanyl and others are reviewed. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
2.
Gintare Grybauskaite-Kaminskiene Dr. Dmytro Volyniuk Dr. Viktorija Mimaite Oleksandr Bezvikonnyi Dr. Audrius Bucinskas Dr. Gintautas Bagdziunas Prof. Juozas V. Grazulevicius 《Chemistry (Weinheim an der Bergstrasse, Germany)》2018,24(38):9581-9591
Derivatives of 9-phenyl-9H-carbazole were synthesized as efficient emitters exhibiting both thermally activated delayed fluorescence and aggregation-induced emission enhancement. Effects of methoxy and tert-butyl substituents at the different positions of carbazolyl groups on the properties of the emitters were studied. Depending on the substitutions, photoluminescence quantum yields (PLQY) of non-doped solid films of the compounds ranged from 17 % to 53 % which were much higher than those observed for the solutions in low-polarity solvent toluene. Compounds substituted at C-3 and C-6 positions of carbazole moiety by methoxy- and tert-butyl- groups showed the highest solid-state PLQY. Ionization potentials of the studied derivatives in solid-state were found to be in the short range of 5.75–5.89 eV. Well-balanced hole and electron mobilities were detected for tert-butyl-substituted compound. They exceeded 10−4 cm2 (V×s)−1 at electric fields higher than 3×105 V cm−1. Two compounds with the highest solid-state PLQYs showed higher efficiencies in non-doped organic light-emitting diodes than in the doped devices. Maximum external quantum efficiency of 7.2 % and brightness of 15000 cd m−2 were observed for the best device. 相似文献
3.
Juozas Kulys Heinz-Josef Deussen Kastis Krikstopaitis Palle Schneider Arturas Ziemys 《Monatshefte für Chemie / Chemical Monthly》2001,38(7):295-304
N-Aryl-N-hydroxy urethanes (AHUs), which are promising N*OH mediators for oxidoreductase catalysis, are electrochemically active redox compounds with a redox potential of 0.35–0.40 V vs. SCE (0.59–0.64 V vs. NHE). Alkyl substituents in the carbamic acid residue have, as expected, only little influence on the redox potential. The highest potential was noticed for N-hydroxy-N-(4-cyanophenyl)-carbamic acid methyl ester. Recombinant Coprinus cinereus peroxidase (rCiP) catalyzes oxidation of the AHUs with apparent bimolecular constants k ox of 2.5ċ104–7.5ċ104 M −1s−1 at pH = 8.5 and 25°C. Structure-function connectivities of the substrates were analysed within the framework of the Marcus cross relationship and by using ab initio quantum chemical calculations. An excellent correlation of the redox potentials and the HOMO energies could be found. However, no correlation of log(k ox) with redox potential and HOMO energy was indicated as predicted by theory. This was explained by specific docking of the substrates in the active center of rCiP. 相似文献
4.
5.
Dr. Deepali Waghray Dr. Gintautas Bagdziunas Jeroen Jacobs Prof. Dr. Luc Van Meervelt Prof. Dr. Juozas Vidas Grazulevicius Prof. Dr. Wim Dehaen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(51):18791-18798
In the present study, we have investigated different strategies for diastereoselective synthesis of thia[n]helicenes. We describe the introduction of different chiral auxiliaries at various positions and investigated their effect in the photocyclization reaction. Different chiral groups were placed at the sterically hindered position of the helical core and their interactions with various solvents and metals like copper were investigated. The use of CuI salts has led to high diastereoselectivity in the photocyclization process and we were successful in obtaining the thia[5]helicene in enantiomerically pure form in good yield. The single diastereomer obtained was characterized by X‐ray crystallography. From the study of the barrier of racemization of these thia[5]helicenes, the stability was found to be comparable to unsubstituted tetrathia[7]helicenes and substituted diazadithia[7]helicenes. This approach provides an easy access to enantiopure helicenes. 相似文献
6.
Dr. Stepas Toliautas Dr. Jelena Dodonova Audrius Žvirblis Ignas Čiplys Artūras Polita Dr. Andrius Devižis Prof. Sigitas Tumkevičius Prof. Juozas Šulskus Dr. Aurimas Vyšniauskas 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(44):10342-10349
Molecular rotors are a class of fluorophores that enable convenient imaging of viscosity inside microscopic samples such as lipid vesicles or live cells. Currently, rotor compounds containing a boron-dipyrromethene (BODIPY) group are among the most promising viscosity probes. In this work, it is reported that by adding heavy-electron-withdrawing −NO2 groups, the viscosity-sensitive range of a BODIPY probe is drastically expanded from 5–1500 cP to 0.5–50 000 cP. The improved range makes it, to our knowledge, the first hydrophobic molecular rotor applicable not only at moderate viscosities but also for viscosity measurements in highly viscous samples. Furthermore, the photophysical mechanism of the BODIPY molecular rotors under study has been determined by performing quantum chemical calculations and transient absorption experiments. This mechanism demonstrates how BODIPY molecular rotors work in general, why the −NO2 group causes such an improvement, and why BODIPY molecular rotors suffer from undesirable sensitivity to temperature. Overall, besides reporting a viscosity probe with remarkable properties, the results obtained expand the general understanding of molecular rotors and show a way to use the knowledge of their molecular action mechanism for augmenting their viscosity-sensing properties. 相似文献
7.
Ruta Lazauskaite Egle Stanislovaityte Juozas V. Grazulevicius 《Monatshefte für Chemie / Chemical Monthly》2008,10(4):887-893
An absorbance probe method was used for the investigation of photolysis of cationic photoinitiators. The rates of the photolysis
of diphenyliodonium hexafluorophosphate (DPIH), diphenyliodonium tetrafluoroborate (DPIB), di(tert-butylphenyl)iodonium tetrafluoroborate (DTIB), di(tert-butylphenyl)iodonium bromate (DTIBr), triphenylsulfonium hexafluorophosphate (TPS) and cyclopropyldiphenylsulfonium tetrafluoroborate (CPS) were studied in the presence of acid indicator quinaldine red (QR) in acetonitrile. Diphenyliodonium hexafluorophosphate and triphenylsulfonium hexafluorophosphate showed the highest photolysis
rate. Photopolymerization of 1,3-di(9-carbazolyl)-2-propanol glycidyl ether (DCPGE) initiated with the iodonium and sulfonium salts in bulk and in solution was studied. It was established that the highest
initial rate of polymerization is characteristic of DCPGE photopolymerization initiated with DPIH and TPS in bulk. The oligomers of DCPGE of number average molecular weight (
[`(Mn)]\overline{M_n}
) ranging from 710 to 1220 were obtained in these reactions in bulk and those with
[`(Mn)]\overline{M_n}
ranging from 1300 to 1600 were obtained in solution. 相似文献
8.
Ruta Lazauskaite Egle Stanislovaityte Juozas V. Grazulevicius 《Monatshefte für Chemie / Chemical Monthly》2008,139(8):887-893
An absorbance probe method was used for the investigation of photolysis of cationic photoinitiators. The rates of the photolysis
of diphenyliodonium hexafluorophosphate (DPIH), diphenyliodonium tetrafluoroborate (DPIB), di(tert-butylphenyl)iodonium tetrafluoroborate (DTIB), di(tert-butylphenyl)iodonium bromate (DTIBr), triphenylsulfonium hexafluorophosphate (TPS) and cyclopropyldiphenylsulfonium tetrafluoroborate (CPS) were studied in the presence of acid indicator quinaldine red (QR) in acetonitrile. Diphenyliodonium hexafluorophosphate and triphenylsulfonium hexafluorophosphate showed the highest photolysis
rate. Photopolymerization of 1,3-di(9-carbazolyl)-2-propanol glycidyl ether (DCPGE) initiated with the iodonium and sulfonium salts in bulk and in solution was studied. It was established that the highest
initial rate of polymerization is characteristic of DCPGE photopolymerization initiated with DPIH and TPS in bulk. The oligomers of DCPGE of number average molecular weight (
) ranging from 710 to 1220 were obtained in these reactions in bulk and those with
ranging from 1300 to 1600 were obtained in solution.
Correspondence: Ruta Lazauskaite, Juozas V. Grazulevicius, Department of Organic Technology, Kaunas University of Technology,
Radvilenu plentas 19, LT-50254 Kaunas, Lithuania. 相似文献
9.
Ruta Lazauskaite Maryte Daskeviciene Vytautas Getautis Juozas V. Grazulevicius 《Monatshefte für Chemie / Chemical Monthly》2009,140(5):565-571
Abstract Photoinitiated cationic polymerizations of various epoxy monomers bearing a carbazole moiety, 9-[3-(allyloxy)-2-(oxiran-2-ylmethoxy)propyl]-9H-carbazole, 9-[3-methoxy-2-(oxiran-2-ylmethoxy)propyl]-9H-carbazole, 9-[2-(oxiran-2-ylmethoxy)ethyl]-9H-carbazole, as well as a composition of 3,6-dibromo-9-(oxiran-2-ylmethyl)-9H-carbazole with 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate were investigated in bulk using triphenyl carbenium
salts having anions such as BF4
−, SnCl5
−, and SbCl6
−. Dark polymerizations of the carbazolyl monomers in the presence of the initiators are studied. These photoinduced polymerization
reactions give oligomers of degree of polymerization 4-22. The effect of the anion of the photoinitiator and polymerization
time on the polymerization reaction is discussed.
Graphical abstract
相似文献
10.
The objective of present study was to establish and compare the contents of secondary metabolites of two Hypericum species, H. perforatum and H. maculatum, native to Lithuania, and to evaluate factors predetermining their variation with some practical implications for utilization and conservation. The HPLC analysis of the ethanolic extracts of the studied species showed some regularity in their composition. Both species contained chlorogenic acid, hyperoside, quercitrin, quercetin and hypericin. The presence of rutin and hyperforin was observed only in H. perforatum. The quantitative analysis showed higher content of quercitrin in H. perforatum, than in H. maculatum, whereas the differences in the contents of quercetin, hypericin and chlorogenic acid were not statistically significant between the species. H. maculatum contained a significantly higher content of hyperoside than H. perforatum. The data on phytochemical analysis suggest almost equivalent use of both H. perforatum and H. maculatum extracts in the food industry, cosmetics and pharmaceutics. 相似文献