1484-14-6Relevant articles and documents
Synthesis and biological evaluation of pyridinium-functionalized carbazole derivatives as promising antibacterial agents
Wang, Pei-Yi,Fang, He-Shu,Shao, Wu-Bin,Zhou, Jian,Chen, Zhuo,Song, Bao-An,Yang, Song
, p. 4294 - 4297 (2017)
Various pyridinium-functionalized carbazole derivatives were constructed by coupling the key fragments of carbazole skeleton and pyridinium nucleus in a single molecular architecture. Antibacterial bioassays revealed that some of the title compounds displ
Synthesis and polymerisation of novel methacrylates with carbazolyl and benzofuranyl pendant groups for photovoltaic applications
Pokladko,Sanetra,Gondek,Bogdal,Niziol,Kityk
, p. 335/[701]-344/[710] (2008)
This article reports properties of photovoltaic devices containing new donor materials - copolymers referred as PCEMB, composed of 2-(carbazol-9-yl) ethyl methacrylate (CEM) and benzofuran-2-carboxylic acid 2-(2- methylacryloyloxy)ethyl ester (MB). Manufactured photovoltaic cells consisted of donor and acceptor (PBT or P3OT) layers sandwiched between ITO covered glass and evaporated aluminum electrode. Performance of the cell was optimized for a copolymer composed of 8% CEM and 92% MB. The efficiency, found equal c.a. =0,03%, was low comparing to other photovoltaic cells reported in the literature. However, following the observed tendencies, it can be supposed that there exists a large reserve for the enhancement of the open circuit voltage through further chemical modifications of the chromophore. In the case of the PDT containing cells, measured Uoc was substantially lower. This fact may be attributed to difference in carrier mobility between this polymer and PCEMB. Simultaneously, the larger sizes of the MB molecule may favor separation of the charges and leads to enhancement of the corresponding voltage.
Synthesis and Morphology of Two Carbazole-Pyrazoline-Containing Polymer Systems and Their Electrical Memory Performance
Lu, Cai-Jian,Li, Hua,Xu, Qing-Feng,Xu, Qing-Hua,Lu, Jian-Mei
, p. 1354 - 1362 (2015)
A new atom-transfer radical polymerization (ATRP) initiator 4-[1-(2-dodecyl-1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinolin-6-yl)-3-(4-nitrophenyl)-4,5-dihydro-1H-pyrazol-5-yl]phenyl 2-bromo-2-methylpropanoate (IN) as an electron acceptor (A) and a monomer 2-(9H-carbazole-9-yl)-ethyl methacrylate (MCz) as an electron donor (D) were simultaneously introduced into two different D-A polymer systems by using the end-functionalizing or blending method. The mass percentage of IN in the end-functionalized polymer PMCz-IN and the mixed polymer composite PMCz+IN were both controlled at approximately 1.0wt. The optical, electrochemical, and surface morphology properties of the two polymeric films prepared by means of spin-coating technology were comparatively investigated. Sandwich devices based on PMCz-IN and PMCz+IN demonstrated nonvolatile write-once-read-many-times memory (WORM) and volatile static random access memory (SRAM) characteristics, respectively, which were further verified by the Kelvin probe force microscopy (KPFM) measurements. The proposed memory mechanism could be attributed to the formation of a stable charge-transfer (CT) complex for PMCz-IN and an unstable CT complex for PMCz+IN. Furthermore, the different distribution of IN in the two polymeric films might be the main reason for the stability of the CT complex.
Palladium-based micellar nanohybrids: Preparation and nonlinear optical response
Papagiannouli, Irene,Demetriou, Maria,Krasia-Christoforou, Theodora,Couris, Stelios
, p. 8779 - 8788 (2014)
In the present work the synthesis and physicochemical characterisation of a new class of Pd-containing micellar nanohybrid systems are presented. The new systems consist of metallic Pd nanoparticles and well-defined diblock copolymers, possessing carbazole and β-ketoester side-chain functionalities, namely poly[2-(N-carbazolyl) ethyl methacrylate]-block-poly[2- (acetoacetoxy) ethyl methacrylate] (CbzEMAx-b-AEMAy). Block copolymer synthesis has been carried out by Reversible Addition-Fragmentation chain Transfer (RAFT) polymerisation. The presence of the β-ketoester groups within these diblock copolymers enabled the complexation and stabilisation of the Pd nanoparticles in tetrahydrofuran. Visualisation of the Pd-containing micellar nanohybrids was realised by means of transmission electron microscopy (TEM), providing information on the metal nanoparticle sizes. The nonlinear optical response of these polymer-metal nanohybrid systems has been systematically studied both in solution and in thin films, using the Z-scan technique, employing 35 ps, visible (532 nm) and infrared (1064 nm) laser excitation. Discussion in regards to the spectral position of the surface plasmon resonance (SPR) of the Pd nanoparticles and its effect on the nonlinear optical response of the micellar systems has been carried out in terms of a two-photon process. The Royal Society of Chemistry.
The Effect of Random and Block Copolymerization with Pendent Carbozole Donors and Naphthalimide Acceptors on Multilevel Memory Performance
Zhang, Qi-Jian,Zhou, Jia-Hui,Li, Hui,He, Jing-Hui,Li, Na-Jun,Xu, Qing-Feng,Chen, Dong-Yun,Li, Hua,Lu, Jian-Mei
, p. 853 - 860 (2018)
Polymeric materials have been widely used in the fabrication of data-storage devices, owing to their unique advantages and defined conduction mechanisms. To date, the most-functional polymers that have been reported for memory devices were synthesized through random copolymerization, whilst there have been no reports regarding the memory effect of block polymers. Herein, we synthesized a random copolymer (PMCz8-co-PMBNa2) and its corresponding block copolymer (PMCz8-b-PMBNa2) to study the effect of the method of polymerization on the memory properties of the corresponding devices. Interestingly, both devices (ITO/PMCz8-co-PMBNa2/Al and ITO/PMCz8-b-PMBNa2/Al) exhibited ternary memory performance, with threshold voltages of ?1.7 V/?3.3 V and ?2.7 V/?3.8 V, respectively. However, based on comprehensive measurements, the memory properties of PMCz8-co-PMBNa2 and PMCz8-b-PMBNa2 were found to be owing to the operation of different conduction mechanisms, which resulted from different molecular stacking in the film state. Therefore, we expect that this work will be helpful for improving our understanding of the conduction mechanisms in polymer-based data-storage devices.
Phosphorescence Spectroscopy for Poly and Its Copolymers with Methyl Methacrylate
Wada, Yoshio,Ito, Shinzaburo,Yamamoto, Masahide
, p. 11164 - 11167 (1993)
Our research project concerned to triplet spectroscopy of 3,6-dibromocarbazole chromophores in a methacrylate copolymer, poly.Owing to the "heavy atom effect" on the rate of singlet-triplet intersystem crossing, the phosphorescence spectra were clearly observed in a wide range of copolymer compositions.Although the triplet interaction between chromophores was weak in 2-methyltetrahydrofuran rigid glass, the copolymer films showed an alteration in spectra from the monomer to the triplet excimer emission with increasing chromophore concentration.The substituted bromine atoms provided a longer interaction distance between chromophores, and a weaker stabilization of energy at the excimer state, compared with unsubstituted carbazole.These effects were interpreted in terms of the extended electron cloud and the bulkiness of bromine atoms.
FRET Phenomenon in Photoreversible Dual-Color Fluorescent Polymeric Nanoparticles Based on Azocarbazole/Spiropyran Derivatives
Keyvan Rad, Jaber,Mahdavian, Ali Reza,Salehi-Mobarakeh, Hamid,Abdollahi, Amin
, p. 141 - 152 (2016)
Incorporation of chromophores into a polymer chain results in prominent photoreversibility and fatigue resistance, photostability over the long term, and restriction of the internal conversion (IC). Here, we report the copolymerization of two photoactive monomers with methyl methacrylate via emulsion polymerization in order to obtain photoswitchable dual-color fluorescent nanoparticles. For this purpose, azocarbazole ethyl acrylate (AzoCzEA) and spiropyran ethyl acrylate (SPEA) were synthesized and the fluorescence polymeric latex nanoparticles were prepared correspondingly. FT-IR and 1HNMR spectra were used to confirm the structure of novel fluorescent AzoCzEA. UV-vis studies of the obtained nanoparticles displayed the spectral features of both AzoCzEA and SPEA under stimuli-irradiation and inclusion of these chromophores into the polymer particles. DSC analysis revealed an increase in Tg of the prepared copolymer, indicating covalently incorporation of the photoactive monomers into the polymer chains. The optimum ratio of two chromophores to achieve complete quenching and highest energy transfer was determined by UV-vis spectroscopy. DLS and SEM results demonstrated particle size distribution of 40-80 nm with spherical morphology. Fluorescence spectra revealed remarkable fluorescence resonance energy transfer (FRET) from AzoCzEA to SPEA after UV irradiation at 365 nm and dual-color characteristic of the prepared nanoparticles. Besides, an enhancement in the photoreversibility, photostability, prevention of IC, dye leakage, and aggregation were studied elaborately. The obtained results were attributed to the involvement of such chromophores into the polymeric matrix via covalent bonding. Labeling and tracking of living cells and rewriteable patterning are potential applications for such dual-color fluorescent nanoparticles.
Synthesis, structure, and biological evaluation of a platinum-carbazole conjugate
Cheun, Young,Koag, Myong-Chul,Naguib, Youssef W.,Ouzon-Shubeita, Hala,Cui, Zhengrong,Pakotiprapha, Danaya,Lee, Seongmin
, p. 116 - 125 (2018)
Cisplatin resistance is caused, in part, by the efficient removal of the helix-distorting cisplatin 1,2-intrastrand cross-links by nucleotide excision repair (NER) machinery. To make a platinum-DNA adduct that causes less helical distortion than the cisplatin 1,2-intrastrand adduct, we designed and synthesized a monofunctional platinum-carbazole conjugate (carbazoplatin). The 2.5?? crystal structure of carbazoplatin-DNA adduct revealed both the monoplatination of the N7 of a guanine (G) base and the intercalation into two G:C base pairs, while causing a minor distortion of the DNA helix. A 50-mer dsDNA containing a single carbazoplatin lesion was poorly processed by UvrABC endonuclease, the prokaryotic NER machinery that detects helical distortion and performs dual incision around the lesion. Our cell viability assay indicated that the cytotoxic pathways of carbazoplatin might be different from those of cisplatin; carbazoplatin was 5–8 times more cytotoxic than cisplatin against PANC-1 and MDA-MB-231 cancer cell lines.
Adjustment of conformation change and charge trapping in ion-doped polymers to achieve ternary memory performance
He, Dongwei,Zhuang, Hao,Liu, Haifeng,Liu, Hongzhang,Li, Hua,Lu, Jianmei
, p. 7883 - 7889 (2013)
Ion-doped poly(4-vinylpyridine) derivatives (P4VPCz), where in the pendant chains the electron-withdrawing pyridine moiety and acceptor carbazole moiety are linked by a flexible alkyl spacer were designed and synthesized. Sandwiched ITO/P4VPCz/Al devices, made through simple spin-coating processes have shown that they could be tuned from a binary to ternary memory performance, by increasing the carbazole content. P4VPCz2 with a 20% mole ratio of the carbazole moiety shows a binary performance according to the charge trapping of the pyridine acceptor in the polymer, while P4VPCz5 which contains a 50% mole ratio of carbazole in the pendant chains, exhibits a ternary data storage ability, probably induced by double mechanisms (i.e. a conformational change and charge trapping). Interestingly, as the carbazole mole ratio reached 80%, the polymer P4VPCz8 has a high conductivity state, with no switching behavior, because of the large amount of doped ions improving the charge transfer mobility. Thus, we hope can offer a guideline to achieve a high-performance multilevel memory material, via combining different mechanisms as well as doping ions.
Photo-induced phosphorescence and mechanoluminescence switching in a simple purely organic molecule
Huang, Qiuqin,Mei, Xiaofei,Xie, Zongliang,Wu, Duobin,Yang, Shuming,Gong, Wenjing,Chi, Zhenguo,Lin, Zhenghuan,Ling, Qidan
supporting information, p. 2530 - 2534 (2019/03/08)
A simple organic molecule, 2-(9H-carbazol-9-yl)ethanol (CZEO), displays both mechanoluminescence (ML) and photo-induced room-temperature phosphorescence (RTP). The D-A type dimer formed in the crystals was found to play a crucial role in the light-stimulated luminescent response, responsible for the turn-on RTP and turn-off ML switching of CZEO.
