4041-21-8Relevant articles and documents
Junction-Controlled Topological Polymerization
Li, Mao,Kang, Shusen,Du, Jia,Zhang, Jian,Wang, Jinxin,Ariga, Katsuhiko
, p. 4936 - 4939 (2018)
Methodology that enables the controlled synthesis of linear and branched polymers from an identical monomer will be a novel pathway for polymer synthesis and processing. Herein we first describe the control of one or both of the C(3)-C(3′) and C(6)-C(6′) coupling reactions of carbazolyl. In a second approach, an identical monomer containing two carbazolyls is polymerized using chemical and electrochemical oxidizers, leading to topologically controllable growth of linear polymers in weak oxidizer or of cross-linked polymer chains in strong oxidizer, with satisfactory long chain propagation of step growth polymerization (Mn=6.0×104 g mol?1, Mw/Mn=2.3). This very simple polymerization with cheap reagents and low levels of waste has provided a flexible pathway for synthesis and processing of polymers.
Robust luminescent small molecules with aggregation-induced delayed fluorescence for efficient solution-processed OLEDs
Huang, Jian,Xu, Zeng,Cai, Zheyi,Guo, Jingjing,Guo, Jiali,Shen, Pingchuan,Wang, Zhiming,Zhao, Zujin,Ma, Dongge,Tang, Ben Zhong
, p. 330 - 339 (2019)
Purely organic luminescent materials with thermally activated delayed fluorescence have the merits of high exciton utilization and thus excellent electroluminescence (EL) efficiency in OLEDs. However, these devices, particularly solution-processed doped OLEDs, usually encounter the troublesome problem of severe efficiency roll-off at high voltages. Herein, two new organic small molecules consisting of electron-withdrawing benzoyl and electron-donating 9-hexylcarbazole and phenoxazine (or 9,9-dimethyl-9,10-dihydroacridine) moieties are designed and synthesized. The crystal and electronic structures, thermal stabilities, electrochemical behaviors and photophysical properties are thoroughly investigated. Whereas these materials are weak emitters in solution, they can fluoresce strongly in spin-coated neat films with greatly enhanced delayed fluorescence, namely they possess interesting aggregation-induced delayed fluorescence (AIDF). Solution-processed nondoped OLEDs are fabricated by using these materials as light-emitting layers, which provide high EL efficiencies of up to 9.02%. Efficient doped OLEDs with varied doping concentrations (10, 30 and 50 wt%) in a 4,4′-bis(carbazol-9-yl)biphenyl (CBP) host are also obtained by a spin-coating technique, offering higher EL efficiencies of up to 12.1%. More importantly, both solution-processed nondoped and doped OLEDs exhibit an extremely small efficiency roll-off (down to 0.08% at 1000 cd m-2 luminance), demonstrating the greatly advanced efficiency stability. These results clearly prove that luminescent materials with AIDF properties are promising candidates for the fabrication of high-performance solution-processed OLEDs.
Synthesis and characterization of new N-{4,6-bis[2-(het)arylvinyl]pyrimidin-2-yl}-substituted polycyclic aromatic imides
Komissarova,Vasyanin,Zhulanov,Lunegov,Shklyaeva,Abashev
, p. 1702 - 1713 (2019)
Two series of new N-{4,6-bis[2-(het)arylvinyl]pyrimidin-2-yl}-substituted aromatic polycyclic imides were synthesized. The synthesized chromophores were characterized by UV and fluorescence spectroscopy, cyclic voltammetry, and quantum chemical density functional theory calculations. A change in the nature of aryl (hetaryl) moieties was found to cause changes in the optical properties of both solutions of these compounds and thin films prepared from these compounds. The replacement of the phthalimide moiety by the 1,8-naphthalimide one has led to a significant increase in the lowest unoccupied molecular orbital energy.
Host–Host Interactions Control Self-assembly and Switching of Triple and Double Decker Stacks of Tricarbazole Macrocycles Co-assembled with anti-Electrostatic Bisulfate Dimers
Dobscha, James R.,Debnath, Sibali,Fadler, Rachel E.,Fatila, Elisabeth M.,Pink, Maren,Raghavachari, Krishnan,Flood, Amar H.
, p. 9841 - 9852 (2018)
Hierarchical assembly provides a route to complex architectures when using building blocks with strong and structurally well-defined recognition elements. These rules are traditionally expressed using cationic templates with reliable metal-ligand bonding but use of anions is rare on account of weak anion–host contacts. We investigate an approach that relies on host–host interactions to fortify assemblies formed between bisulfate anion dimers, [HSO4???HSO4]2?, and shape-persistent macrocycles called tricarbazole triazolophanes. These macrocycles have significant self-association. In chloroform, they form high fidelity, triple-decker stacks with bisulfate dimers. The strength of host–host interactions allows for preferential formation of the 3:2 tricarb:bisulfate architecture over an ion-paired architecture seen with analogous macrocycles with much weaker self-association. Solvent was expected and found to tune host–host contacts enabling formation of a 2:2 complex and solvent-driven switching between triple- and double-stacked structures. Crystallography of the 2:2:2 complex supports the idea that significant host–host interactions with tricarb arises from dipole-stabilized π-stacking. Computational studies were also conducted further highlighting the importance of host–host interactions in stacked complexes of tricarb. These findings unambiguously verify the importance of host–host interactions in the assembly and stability of discrete, responsive anion-templated architectures.
Chlorine (Cl) - Substituted Carbazole Based A-π-D-π-a Push-Pull Chromophores as Aggregation Enhanced Emission (AEE) Active Viscosity Sensors: Synthesis, DFT and NLO Approach
Lokhande, Prerana K. M.,Patil, Dinesh S.,Kadam, Mayuri,Sekar, Nagaiyan
, p. 779 - 795 (2019)
Three new carbazole functionalized A-π-D-π-A extended chromophores 4a, 4b and 4c comprising of different chemical functional groups on C=C bond with the assistance of chlorovinylene group in π-conjugation are synthesized and investigated spectroscopically. We have investigated the effect of different electron acceptors - carboxycyanomethylene, dicyanomethylene and 2-(benzothiazol-2-yl) cyanomethylene, the effect of the insertion of chlorine in π-conjugation on photophysical properties and the effect of double acceptors. The chromophores 4a, 4b and 4c exhibited positive solvatochromism with large Stokes shifts and bright orange to red solid-state fluorescence. Amongst all the three compounds 4c exhibited maximum emission wavelength at 615?nm in DMSO. They presented characteristic twisted intramolecular charge transfer (TICT) emission. Observations exhibited that 4c containing long hexyl group in donor unit and 2-(benzothiazol-2-yl) cyanomethylene as an acceptor group formed an aggregate in the mixture of solvents and exhibited better aggregation enhanced emission (AEE) compared to the other two derivatives. Amongst the three styryls, 4c showed the highest emission intensity 299?a.u. at 90% water:DMF fraction (fw). Chromophores 4a-4c also exhibited good fluorescence response towards viscosity. Among the three fluorescent molecular rotors (FMR), 4c exhibited excellent viscosity sensitivity with x value = 0.687. The Non-linear (NLO) characters are estimated with the help of solvatochromic and computational methods using the functionals, B3LYP and CAM-B3LYP. The dyes showed large “linear polarizability (αCT)”, “first order hyperpolarizability” (β) and “second order hyperpolarizability” (γ) values which show that synthesized styryls can be used as a “NLO” material. The αCT, β and γ for 4c are found to be the maximum amongst the all three dyes which can be ascribed to the smaller band gap apparent from experimental as well as DFT method.
Toward purple-to-green-to-transmissive-to-black color switching in polymeric electrochrome
Karabiyik, Elif,Sefer, Emre,Baycan Koyuncu, Fatma,Tonga, Murat,?zdemir, Eyüp,Koyuncu, Sermet
, p. 8578 - 8584 (2014)
A novel 3,4-ethylenedioxythiophene (EDOT)-based donor-acceptor electroactive monomer (HCQE) bearing carbazole subunit is synthesized, and then the corresponding polymer, poly(HCQE), is directly deposited onto ITO/glass surface via electrochemical process. Spectroelectrochemical studies demonstrate that poly(HCQE) is capable of showing both n- and p-doping processes. Hence, this low band polymer serves the multielectrochromic feature at three separate states (-0.4 to -2.0 V, -0.4 to 1.2 V, and 1.2 to 2.0 V) with a highly unique near colorless and colored states, fast switching times, redox switching stability, and exceptional transmittance change. To the best of our knowledge, this is the first report of a neutral state green multielectrochromic polymer exhibiting successive switching of colored-to-bleached-to-colored in three distinct regimes.
Regulation of aggregation-induced emission color of α-cyanostilbene luminogens through donor engineering of amino derivatives
Tonga, Murat
supporting information, (2021/03/16)
In this contribution, α-cyanostilbene-based D-π-A-π-D type compounds consisting of different substituents on the amino donor group (e.g., fused, aryl/alkyl, and dialkyl) were designed, synthesized and their aggregation-induced emission was investigated thoroughly. The incorporation of these substituents furnished AIE features with tunable emission colors ranging from green-to-yellow-to-red. The compounds all showed a weak emission in THF; however, they showed an enhanced emission upon addition of water by forming emissive aggregates, which may arise from the restriction of twisted intramolecular charge transfer and E/Z isomerization. The DFT calculations revealed that the luminogens adopted distinctive conformations including a highly twisted one and a relatively coplanar one with the variation in the amino substituents.
A PHENYLMETHANONE FUNCTIONALIZED CARBAZOLE, A PROCESS FOR PREPARATION AND USE THEREOF
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Page/Page column 8; 13-14, (2021/03/05)
The present invention discloses a phenylmethanone functionalized carbazole of formula (I), a process for the preparation and use thereof, Formula (I) wherein, R1, R2, R3 are selected from group consisting of hydrogen, alkyl chain (A), phenylmethanone (B) and 4-substituted phenylmethanone (C), optionally R2 and R3 are not hydrogen at the same time.
Carbazole-based π-conjugated 2,2′-Bipyridines, a new class of organic chromophores: Photophysical, ultrafast nonlinear optical and computational studies
Bodapati, Ramakrishna,Das, Samar K.,Dey, Gaurav Ranjan,Jose, K. V. Jovan,Krishnakanth, Katturi Naga,Ramteke, Gunjan R.,Rao, S. Venugopal
, (2020/11/03)
The developmen of donor-acceptor (D-A) architecture based organic chromophores with large two-photon absorption (2 PA) cross-sections are essential for myriad of applications, ranging from nonlinear microscopy to biomedical imaging. Here, we present the results from a comprehensive study of 2 PA cross-sections of a new series of carbazole mono substituted-π-conjugated-2,2′-bipyridine derivatives with D-π-A architecture, possessing carbazole as the donor moiety and bipyridine core as an acceptor. Further, we have extended the π-conjugation by introducing the phenyl and butoxy substituted phenyl linkers. The fluorescence properties of these D-A chromophores are highly sensitive to solvent polarity and alteration of electron donor functionalities. The relevant computation studies support our experimental results, e.g., a shift in emission maxima and band gaps of the molecules. The third-order nonlinear optical (NLO) properties of the title donor-acceptor (D-A) chromophores demonstrated that 2 PA cross-section values are in the range of 6–39 GM, obtained using ~50 fs (fs) laser pulses at a wavelength of 800 nm. Further, the nonlinear refractive indices (n2) of these chromophores were found to be ~10?14 cm2/W, rendering them potential optical switching candidates since the coefficients were obtained with kHz, fs pulses extracting pure electronic nonlinearities. Based on our experimental findings and theoretical calculations presented in this study, we believe that carbazole-based π-conjugated 2,2′-bipyridines, demonstrated in this work, would be potential ligands to obtain a series of transition metal coordination complexes of interesting physical properties (for example, superior NLO behaviour).
Effect of different acceptors on N-hexyl carbazole moiety for dye-sensitized solar cells: design, characterization, molecular structure, and DSSC fabrications
Abusaif, Moustafa S.,Abu-Saied,Fathy,El-Sherif, Ahmed A.,Kashyout,Selim, Mohamed R.,Ammar, Yousry A.
, p. 949 - 960 (2020/10/19)
Hexyl carbazole derivatives are one of the most prominent dye scaffolds in the dye-sensitized solar cells (DSSCs). New substituted carbazole dyes such as DRA-HC, DCA-HC, and DTC-HC were synthesized for DSSCs. These dyes are containing hexyl moiety as electron donor and rhodanine-3-acetic acid, cyanoacetic acid and tetracyanoethylene as an electron acceptor linked to carbazole moiety. The relation between dye structures, photophysical/electrochemical, molecular structure and DSSC manufacturing had been discussed. All structures showed more positive ground-state oxidation potential than I?/I?3 and more negative excited state oxidation potential than the conduction band edge of the semiconductor. The highest efficiency of the DSSCs was obtained in the case of DCA-HC dye (η = 1.41%, VOC = 708?mV, FF = 0.81, and JSC = 2.45?mA?cm?2 with 100?mW?cm?2) compared to other synthesized dyes.
