22706-22-5Relevant academic research and scientific papers
Synthesis and characterization of non-symmetrical photoswitchable DTE(OMe) sensitizers
Ziebart, Nandor,Schroeer, Pierre,Rueck-Braun, Karola
, p. 5561 - 5566 (2018)
DTE-BODIPY 2 and BTD-DTE 3 were designed for reversible light modulation of electron- and energy-transfer processes on TiO2, and showed almost complete ring closure. In BTD-DTE 3 the BTD is an acceptor group in the open form (OF), and an energy donor group in the closed form (CF), but this property is depending on the solvent. Quantum yields for ring closure decreased (BTD-DTE 3: factor 5; DTE-BODIPY 2: factor 12) compared to DTE 1, because of π-system elongation in OFs, and also cycloreversion quantum yields became smaller (BTD-DTE 3: factor 1.4; DTE-BODIPY 2: factor 2.2).
Supramolecular Synthesis Based on a Combination of Se?N Secondary Bonding Interactions with Hydrogen and Halogen Bonds
Eichstaedt, Katarzyna,Wasilewska, Aleksandra,Wicher, Barbara,Gdaniec, Maria,Po?oński, Tadeusz
, p. 1282 - 1293 (2016)
Examination of the solid state structures of 2,1,3-benzoselenadiazole complexes with hydrogen or halogen bond donors has demonstrated that the 2,1,3-benzoselenadiazole molecules preferably form centrosymmetric dimers with use of [Se-N]2 supramolecular synthon, whereas the two remaining nitrogen atoms not involved in the [Se-N]2 supramolecular interactions can act as acceptors of hydrogen or halogen bonds. Cocrystallization of selenadiazoles with monofunctional hydrogen or halogen bond donors like pentafluorophenol, pentafluorobenzoic acid, or pentafluoroiodobenzene results in formation of binary discrete complexes. One- or two-dimensional aggregates based on selenadiazole [Se-N]2 dimers as building blocks were prepared using bifunctional hydrogen or halogen bond donors like resorcinol, tetrafluororesorcinol, tetrafluorohydroquinone, and 1,4-diiodotetrafluorobenzene. During the complexation of selenadiazoles with hydroquinone, anilic acid, or chloranilic acid a competition between Se?N and Se?O interactions resulted in breaking of the [Se-N]2 synthon.
Observation of Microheterogeneity in Highly Concentrated Nonaqueous Electrolyte Solutions
Robertson, Lily A.,Li, Zhixia,Cao, Yu,Shkrob, Ilya A.,Tyagi, Madhusudan,Smith, Kyle C.,Zhang, Lu,Moore, Jeffrey S.,Zhyang
, p. 8041 - 8046 (2020)
The development of models to describe structure and dynamics of nonaqueous electrolyte solutions is challenging, and experimental observations are needed to form a foundation. Here, neutron scattering is used to probe molecular dynamics in nonaqueous organic electrolytes. Two solutions were compared: One contained symmetrical electrolyte molecules prone to crystallize, and one contained desymmetrized electrolyte molecules preferring disordered states. For the latter, calorimetry and neutron data show that a disordered fluid persists to very low temperatures at high concentrations. Upon heating, localized cold crystallization occurs, leading to burst nucleation of microcrystalline solids within fluid phases. Our findings indicate molecular clustering and point to solvation inhomogeneities and molecular crowding in these concentrated fluids.
The improvement of photovoltaic performance of quinoline-based dye-sensitized solar cells by modification of the auxiliary acceptors
?i?man, ?lkay,Arkan, Burcu,Arslan, Bar?? Se?kin,Avc?, Davut,Derin, Yavuz,Gezgin, Merve,Nebio?lu, Mehmet,Tutar, Ahmet
, (2020/10/07)
Three new dyes containing diphenylamine as electron donor, benzene (BIM1), benzothiadiazole (BTD) (BIM2) and N-ethylhexylbenzotriazole (BTZ) (BIM3) as auxiliary electron acceptors, quinoline as π-bridge and cyanoacrylic acid as anchoring group were synthesized in D-A-π-A structure for use in dye-sensitized solar cells (DSSCs). The optical, electrochemical, theoretical and photovoltaic methods were performed to understand the auxiliary acceptor influence on the performance of these dyes. Compared to the other dyes, the DSSC with dye BIM3 slightly increases the open circuit voltage (Voc) owing to the retardation of charge recombination by BTZ. However, replacement of benzene or BTZ by BTD unit causes a large red shift of the absorption spectra, leading BIM2 cell to produce the highest short circuit current density (Jsc). Thus, among the three D-A-π-A dyes, BIM2 is determined to be the most efficient dye, which reached a Voc of 0.627 V and Jsc of 11.53 mA cm–2, corresponding to an overall power conversion efficiency of 5.21 % in the presence of chenodeoxycholic acid (CDCA) as the coadsorbent. These results suggest that the insertion of benzothiadiazole as auxiliary acceptor into quinoline-based D-A-π-A dyes can effectively improve photovoltaic performance of DSSCs.
Synthesis of novel halogenated heterocycles based on o‐phenylenediamine and their interactions with the catalytic subunit of protein kinase ck2
Maciejewska, Agnieszka Monika,Paprocki, Daniel,Poznański, Jaros?aw,Speina, El?bieta,Winiewska‐szajewska, Maria
supporting information, (2021/06/09)
Protein kinase CK2 is a highly pleiotropic protein kinase capable of phosphorylating hundreds of protein substrates. It is involved in numerous cellular functions, including cell viability, apoptosis, cell proliferation and survival, angiogenesis, or ER‐stress response. As CK2 activity is found perturbed in many pathological states, including cancers, it becomes an attractive target for the pharma. A large number of low‐mass ATP‐competitive inhibitors have already been developed, the majority of them halogenated. We tested the binding of six series of halogenated heterocyclic ligands derived from the commercially available 4,5‐dihalo‐benzene‐1,2‐diamines. These ligand series were selected to enable the separation of the scaffold effect from the hydrophobic interactions attributed directly to the presence of halogen atoms. In silico molecular docking was initially applied to test the capability of each ligand for binding at the ATP‐binding site of CK2. HPLC‐derived ligand hydrophobicity data are compared with the binding affinity assessed by low‐volume differential scanning fluorimetry (nanoDSF). We identified three promising ligand scaffolds, two of which have not yet been described as CK2 inhibitors but may lead to potent CK2 kinase inhibitors. The inhibitory activity against CK2α and toxicity against four reference cell lines have been determined for eight compounds identified as the most promising in nanoDSF assay.
Fluorescence emission enhancement of a T-shaped benzimidazole with a mechanically-interlocked ‘suit’
Xu, Houyang,Lin, Meng-Di,Yuan, Jun,Zhou, Baiyang,Mu, Yingxiao,Huo, Yanping,Zhu, Kelong
supporting information, p. 3239 - 3242 (2021/04/06)
A fluorescent T-shaped benzimidazole was successfully designed and interlocked in a bicyclic macrocycle to form a suit[1]ane through supramolecular templated-synthesis. Compared with the bare fluorophore, suit[1]ane requires nearly two times the concentration to initialize the aggregation-caused quenching effect in solution. Furthermore, an 8-fold higher solid-state fluorescence quantum yield (21.7%) is also achieved. By taking advantage of mechanical bonding and molecular packing, such fluorescence emission enhancement through formation of a suitane opens the way to new complex fluorescent materials.
Synthesis and Characterization of Acid-Responsive Luminescent Fe(II) Metallopolymers of Rigid and Flexible Backbone N-Donor Multidentate Conjugated Ligands
Kumar, Anil,Bawa, Shubham,Ganorkar, Kapil,Ghosh, Sujit Kumar,Bandyopadhyay, Anasuya
, p. 1746 - 1757 (2020/02/05)
In this report we have disclosed the syntheses and properties of two new conjugated organic moieties bearing the same coordination sites but possessing different backbone rigidities and rotational flexibilities. Two new metallopolymers have been synthesized from the corresponding ligands under identical reaction conditions, and they have been thoroughly characterized through different techniques to understand the effect of backbone rigidity on the evolution of different properties in these metallopolymers. A FESEM micrograph of the rigid metallopolymer confirms the formation of a rigid nanorod type structure, while long agglomerated nanofiber strands are visible on the substrate in the case of the flexible analogue. All of the newly synthesized materials are fluorescence active. An Fe(II) metallopolymer of the flexible ligand showed huge changes in emission properties in the presence of different acids and showed a possibility of it being used as a thin film acid vapor sensor. All of the materials showed reversible electrochemical activity, and both of these polymers have shown electroluminescence when an appropriate potential is applied.
Between Aromatic and Quinoid Structure: A Symmetrical UV to Vis/NIR Benzothiadiazole Redox Switch
Rietsch, Philipp,Sobottka, Sebastian,Hoffmann, Katrin,Popov, Alexey A.,Hildebrandt, Pascal,Sarkar, Biprajit,Resch-Genger, Ute,Eigler, Siegfried
, p. 17361 - 17365 (2020/12/01)
Reversibly switching the light absorption of organic molecules by redox processes is of interest for applications in sensors, light harvesting, smart materials, and medical diagnostics. This work presents a symmetrical benzothiadiazole (BTD) derivative with a high fluorescence quantum yield in solution and in the crystalline state and shows by spectroelectrochemical analysis that reversible switching of UV absorption in the neutral state, to broadband Vis/NIR absorption in the 1st oxidized state, to sharp band Vis absorption in the 2nd oxidized state, is possible. For the one-electron oxidized species, formation of a delocalized radical is confirmed by electron paramagnetic resonance spectroelectrochemistry. Furthermore, our results reveal an increasing quinoidal distortion upon the 1st and 2nd oxidation, which can be used as the leitmotif for the development of BTD based redox switches.
Constructing fused bis-isatins from pyrroloindoles using direct oxidation approach and re-visiting indophenine reaction
Bhanvadia, Viraj J.,Choudhury, Anwesha,Iyer, Parameswar Krishnan,Patel, Arun L.,Zade, Sanjio S.
, (2020/09/23)
Two novel electron accepting bis-isatins, having fused bis-lactam rings have been synthesized from corresponding pyrroloindoles 7 and 14 by one-pot direct oxidation approach involving oxidant NBS with or without co-oxidant TBHP in DMF/CHCl3. Synthesized fused bis-isatins 8 and 15 are extensively studied for thermal, photophysical, electrochemical and thin-film morphological properties and are found to have characteristic properties like solid-solid transitions, visible light absorption, lowered FMO energy levels (LUMOs below ?4.1 eV and HOMOs below ?5.9 eV) as well as oriented packing of molecules in the film state. The famous indophenine reaction is re-visited with fused bis-isatins to form conjugated polymers P-1 and P-2, having quinoidal pyrroloindole dione units. The polymers are studied for thermal, photophysical, electrochemical and thin-film morphological properties indicating sufficiently high thermal stability (up to 200 °C), extended absorptions up to near IR region, lowered FMO energy levels (LUMOs below ?4.3 eV and HOMOs below ?5.8 eV) and amorphous nature of polymer films.
Design and development of dithienopyrrolobenzothiadiazole (DTPBT)-based rigid conjugated polymers with improved hole mobilities
Bhanvadia, Viraj J.,Machhi, Hiren K.,Soni, Saurabh S.,Zade, Sanjio S.,Patel, Arun L.
, (2020/10/12)
Donor-acceptor integrated ladder-type dithienopyrrolobenzothiadiazole (DTPBT)-based conjugated building blocks have been used to develop rigid conjugated polymers by copolymerizing them with synthesized ladder-type indoloquinoxaline, π-extended isoindigo and π-extended 2,1,3-benzothiadiazole-based conjugated building blocks. Structural aspects of synthesized building blocks are studied by single-crystal X-ray diffraction, which revealed the co-planar structure of indoloquinoxaline-scaffold while twisted but intramolecularly hydrogen-bonded structures of π-extended isoindigo- and 2,1,3-benzothiadiazole-scaffolds with number of intermolecular non-bonding interactions. The synthesized DTPBT-based conjugated polymers P-1, P-2 and P-3 are studied for photophysical and electrochemical properties and are found to have moderate to good visible light absorptivity with HOMO energy levels below ?5.0 eV. The X-ray diffraction studies indicate strong π?π stacking interactions induced face-on arrangement of polymer chains respective to the substrate. Polymers show π?π stacks promoted high space-charge limited current (SCLC) hole mobilities ranging between 5.6 × 10?4 –1.3 × 10?3 cm2V?1s?1. The obtained SCLC hole mobility data in tandem with the studied structural aspects of monomers and morphological aspects of polymers, suggest that the combination of ladder-type DTPBT-scaffolds (capable of intermolecular π?π interactions) with non-ladder-type planar and structurally rigid π-extended conjugated scaffolds (capable of intermolecular π?π and other non-bonding interactions) is beneficial for getting good hole mobilities.
