Journal articles: 'Imidazole-based donors'

1

Spicer, Mark D., and John Reglinski. "Soft Scorpionate Ligands Based on Imidazole-2-thione Donors." European Journal of Inorganic Chemistry 2009, no. 12 (April 2009): 1553–74. http://dx.doi.org/10.1002/ejic.200801240.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Zhao, Yibo, Liqian Zhang, Xu Li, Yanhui Shi, Ruru Ding, Mengting Teng, Peng Zhang, Changsheng Cao, and Peter J. Stang. "Self-assembled ruthenium (II) metallacycles and metallacages with imidazole-based ligands and their in vitro anticancer activity." Proceedings of the National Academy of Sciences 116, no. 10 (February 14, 2019): 4090–98. http://dx.doi.org/10.1073/pnas.1818677116.

Full text

Abstract:

Six tetranuclear rectangular metallacycles were synthesized via the [2+2] coordination-driven self-assembly of imidazole-based ditopic donor 1,4-bis(imidazole-1-yl)benzene and 1,3-bis(imidazol-1-yl)benzene, with dinuclear half-sandwichp-cymene ruthenium(II) acceptors [Ru2(µ-η4-oxalato)(η6-p-cymene)2](SO3CF3)2, [Ru2(µ-η4-2,5-dioxido-1,4-benzoquinonato)(η6-p-cymene)2](SO3CF3)2and [Ru2(µ-η4-5,8-dioxido-1,4-naphtoquinonato)(η6-p-cymene)2](SO3CF3)2, respectively. Likewise, three hexanuclear trigonal prismatic metallacages were prepared via the [2+3] self-assembly of tritopic donor of 1,3,5-tri(1H-imidazol-1-yl)benzene with these ruthenium(II) acceptors respectively. Self-selection of the single symmetrical and stable metallacycle and cage was observed although there is the possibility of forming different conformational isomeric products due to different binding modes of these imidazole-based donors. The self-assembled macrocycles and cage containing the 5,8-dioxido-1,4-naphtoquinonato (donq) spacer exhibited good anticancer activity on all tested cancer cell lines (HCT-116, MDA-MB-231, MCF-7, HeLa, A549, and HepG-2), and showed decreased cytotoxicities in HBE and THLE-2 normal cells. The effect of Ru and imidazole moiety of these assemblies on the anticancer activity was discussed. The study of binding ability of these donq-based Ru assemblies with ctDNA indicated that the complex 9 with 180° linear 1 ligand has the highest bonding constantKbto ctDNA.

APA, Harvard, Vancouver, ISO, and other styles

3

Višnjevac, Aleksandar, Jérôme Gout, Olivia Bistri-Aslanoff, and Olivia Reinaud. "Biomimetic resorcinarene-based copper(II) complex." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C1374. http://dx.doi.org/10.1107/s2053273314086252.

Full text

Abstract:

"The synthesis, structural characterization, as well as the chemical activity studies of a Cu(II) ""bowl complex", based on the resorcin[4]arene scaffold with three imidazole-containing coordinating arms grafted at the large rim, is presented. This complex is a biomimetic model of a metalloenzyme active site where a cofacial triade of amino-acid residues holds the metal ion in the active site [1]. The trisimidazole ligand reacts with a stoichiometric amount of copper(II) perchlorate to produce a Cu(II) diperchloratocomplex 1. Spectroscopic studies revealed a 5-coordinate SBP environment for the Cu(II) center provided by three imidazole arms, and two extra donors, one embedded in the resorcinarene cavity, the other exposed to the solvent, in exo position. These two labile sites are occupied by either coordinating solvent molecules or residual water, and are readily displaced by carboxylate donors, the position of which (endo or exo) is under tight control of the bowl-cavity. The reaction of 1 with CH3COONa led to a formation of the Cu(II) acetatocomplex 2. Molecular structure of 2 features a rigidified resorcinarene bowl, which was constructed by the addition of the four methylene bridges between the eight hydroxyl groups of the octol precursor [2]. The isolated resorcinarene basket reveals an approximate, non-crystallographic, 4mm point symmetry, and can easily host small guest molecules. Three methylimidazole-containing coordination arms at the large rim coordinate the Cu (II) ion. Its coordination sphere is completed by two O atoms from the intra-cavity bound acetate. The electron donors form a distorted square pyramide, where one of the nitrogens is at the appical position. The endo-coordination of the acetate is supported by an extensive network of intramolecular C-H···O and C-H···π interactions. Complex 2 crystallizes in P21/c space group; a=32.3310 (4)Å, b=11.5490 (1)Å, c=21.6020 (2)Å, beta=102.281(3)0."

APA, Harvard, Vancouver, ISO, and other styles

4

Fu, Lin, Yi Zhang, Zhongjie Ren, Huihui Li, Xiaoli Sun, and Shouke Yan. "Flexible and Fatigue‐Resistant Ternary Electrical Memory Based on Alternative Copolysiloxane with Carbazole Donors and Imidazole‐Modified Naphthalimide Acceptors." Advanced Materials Technologies 4, no. 8 (May 8, 2019): 1900084. http://dx.doi.org/10.1002/admt.201900084.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Lampeka, Rostislav D., Zamira D. Uzakbergenova, and Victor V. Skopenko. "Spectroscopic and X-Ray Investigation of Cobalt(III) Complexes with 2-Oximinocarboxylic Acids." Zeitschrift für Naturforschung B 48, no. 4 (April 1, 1993): 409–17. http://dx.doi.org/10.1515/znb-1993-0403.

Full text

Abstract:

Mixed complexes of Co(III) with 2-oximinopropionic (H2A) or 2-oximino-3-phenylpropionic (H2B) acid and different amine (imidazole, benzimidazole, pyridine, β-picoline, γ-picoline) are reported. Characterization of the complexes was based upon elemental analysis, conductivity and JR, 1H NMR, and electronic absorption spectra, and X-ray diffraction analysis. The organic ligands behave as O,N donors via the carboxyl oxygen and the oxime nitrogen atoms. A trans-octahedral structure has been assigned to the bis(2-oximinocarboxylato)bis(amine)cobalt(III) on the basis of 1H NMR data.The crystal and molecular structures of the complexes trans-[bis(2-oximinopropionato)bis-(imidazole)]- (I) and trans-[bis(2-oximinopropionato)bis(pyridine)]cobalt(III) (II) were determined. I crystallizes in space group P2/n with a = 14.1 67(2), b = 8.774(1), c = 14.785(2) Å,β = 113.37(1)°, Z = 4, Dcalc = 1.568 g · cm-3. II crystallizes in space group P1̄ with a = 9.122(2), b = 10.038(2), c = 11.759(2) Å, α = 69.95(1)°, β = 67.47(2)°, γ = 69.49(2)°, Ζ = 2, Dcalc = 1.547 g cm-3. The structures were refined to unweighted R factors of 0.036 and 0.028, respectively. The coordination sphere around Co is pseudo-octahedral with the 2-oximinopropionato ligands occupying four equatorial positions, and the amines in axial positions.

APA, Harvard, Vancouver, ISO, and other styles

6

Aggarwal, Mayank, Chingkuang Tu, David Silverman, and Robert McKenna. "Insights into Activity Enhancement of H64A Carbonic Anhydrase by Imidazoles." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C803. http://dx.doi.org/10.1107/s2053273314091967.

Full text

Abstract:

Human carbonic anhydrases (CAs) are zinc metalloenzymes that catalyze the hydration and dehydration of CO2 and HCO3-, respectively. The reaction follows a ping-pong mechanism, where the rate limiting step is the transfer of a proton from the zinc-bound solvent out of the active site, via His64 which is widely believed to be the proton shuttling residue. Being involved in a number of physiological processes such as respiration, pH regulation, ureagenesis etc., CAs are therapeutic targets for inhibition to treat various diseases. However, the physiologically dominant isoform is CA II, which is catalytically highly efficient and is easily crystallizable. Thus, most of our knowledge in the design of CA inhibitors with pharmacological applications is based on detailed CA II crystallographic studies. The catalytic activity of a variant of CA II in which His64 is replaced with Ala (H64A CA II) can be enhanced by exogenous proton donors/acceptors, usually derivatives of imidazoles and pyridines. This article examines the mechanism through which this activity enhancement might occur. X-ray crystal structures of H64A CA II in complex with four imidazole derivatives have been determined and reveal multiple binding sites. We have identified two molecules of imidazoles that bind in region that is otherwise occupied by the "in" and "out" dual conformation of the side chain of His64 in wild-type CA II. The data presented here not only corroborates the importance of imidazole side chain of His64 in proton transfer during CA catalysis, but also provides a complete structural understanding of the mechanism by which imidazoles enhance (and inhibit when used in higher concentrations) the activity of H64A CA II. In addition to inhibition of CA by these imidazoles, the presence of a large number of binding sites also gives insights and preliminary data required to fragment addition approach of drug design against CA.

APA, Harvard, Vancouver, ISO, and other styles

7

Bocian, Szymańska, Brykczyńska, Kubicki, Wałęsa-Chorab, Roviello, Fik-Jaskółka, Gorczyński, and Patroniak. "New Artificial Biomimetic Enzyme Analogues based on Iron(II/III) Schiff Base Complexes: An Effect of (Benz)imidazole Organic Moieties on Phenoxazinone Synthase and DNA Recognition." Molecules 24, no. 17 (August 31, 2019): 3173. http://dx.doi.org/10.3390/molecules24173173.

Full text

Abstract:

Elucidation of the structure and function of biomolecules provides us knowledge that can be transferred into the generation of new materials and eventually applications in e.g., catalysis or bioassays. The main problems, however, concern the complexity of the natural systems and their limited availability, which necessitates utilization of simple biomimetic analogues that are, to a certain degree, similar in terms of structure and thus behaviour. We have, therefore, devised a small library of six tridentate N-heterocyclic coordinating agents (L1–L6), which, upon complexation, form two groups of artificial, monometallic non-heme iron species. Utilization of iron(III) chloride leads to the formation of the 1:1 (Fe:Ln) ‘open’ complexes, whereas iron(II) trifluoromethanosulfonate allows for the synthesis of 1:2 (M:Ln) ‘closed’ systems. The structural differences between the individual complexes are a result of the information encoded within the metallic centre and the chosen counterion, whereas the organic scaffold influences the observed properties. Indeed, the number and nature of the external hydrogen bond donors coming from the presence of (benz)imidazole moieties in the ligand framework are responsible for the observed biological behaviour in terms of mimicking phenoxazinone synthase activity and interaction with DNA.

APA, Harvard, Vancouver, ISO, and other styles

8

Jian, Shou-Jun, Qian-Qian Han, Huai-Xia Yang, and Xiang-Ru Meng. "A new three-dimensional zinc(II) coordination polymer involving 2-[(1H-1,2,4-triazol-1-yl)methyl]-1H-benzimidazole and benzene-1,4-dicarboxylate ligands." Acta Crystallographica Section C Structural Chemistry 72, no. 7 (June 14, 2016): 530–35. http://dx.doi.org/10.1107/s2053229616008779.

Full text

Abstract:

Metal–organic frameworks (MOFs) based on multidentate N-heterocyclic ligands involving imidazole, triazole, tetrazole, benzimidazole, benzotriazole or pyridine present intriguing molecular topologies and have potential applications in ion exchange, magnetism, gas sorption and storage, catalysis, optics and biomedicine. The 2-[(1H-1,2,4-triazol-1-yl)methyl]-1H-benzimidazole (tmb) ligand has four potential N-atom donors and can act in monodentate, chelating, bridging and tridentate coordination modes in the construction of complexes, and can also act as both a hydrogen-bond donor and acceptor. In addition, the tmb ligand can adopt different coordination conformations, resulting in complexes with helical structures due to the presence of the flexible methylene spacer. A new three-dimensional coordination polymer, poly[[bis(μ2-benzene-1,4-dicarboxylato)-κ4O1,O1′:O4,O4′;κ2O1:O4-bis{μ2-2-[(1H-1,2,4-triazol-1-yl)methyl-κN4]-1H-benzimidazole-κN3}dizinc(II)] trihydrate], {[Zn(C8H4O4)(C10H9N5)]·1.5H2O}n, has been synthesized by the reaction of ZnCl2with tmb and benzene-1,4-dicarboxylic acid (H2bdic) under solvothermal conditions. There are two crystallographically distinct bdic2−ligands [bdic2−(A) and bdic2−(B)] in the structure which adopt different coordination modes. The ZnIIions are bridged by tmb ligands, leading to one-dimensional helical chains with different handedness, and adjacent helices are linked by bdic2−(A) ligands, forming a two-dimensional network structure. The two-dimensional layers are further connected by bdic2−(B) ligands, resulting in a three-dimensional framework with the topological notation 66. The IR spectra and thermogravimetric curves are consistent with the results of the X-ray crystal structure analysis and the title polymer exhibits good fluorescence in the solid state at room temperature.

APA, Harvard, Vancouver, ISO, and other styles

9

Vicini, John L., and Wesley Harris. "PSVIII-17 Modeling of glyphosate speciation in rumen fluid of cattle." Journal of Animal Science 98, Supplement_4 (November 3, 2020): 257. http://dx.doi.org/10.1093/jas/skaa278.464.

Full text

Abstract:

Abstract Glyphosate, the active ingredient in Roundup® agricultural herbicides, is used on crops that are commonly grown for animal feed. Even though there has not been empirical data to suggest that animal productivity and health are affected when glyphosate-based products are used as labeled, accusations based on hazard identification alone have circulated widely. One of these accusations originates regarding a patent that was never held by Monsanto (now part of the Bayer Group) that did not include glyphosate. This claim hypothesizes that glyphosate could chelate minerals in the gut and prevent absorption. Formation constants measure the strength of complexation between metal ions and ligands and can be used to model the speciation in mixtures of minerals, amino acids, VFAs, and glyphosate as they exist in the rumen. The amines and carboxylic acids of all amino acids and functional side chains such as the imidazole group of histidine are potential donors for binding minerals. Likewise, carboxylic acid groups from VFAs are prevalent sources for binding of minerals. Literature references of concentrations of minerals and amino acids were used along with a measurement of glyphosate, and speciation calculations were performed at three pH’s commonly encountered in the rumen (5.8, 6.3 and 6.8). This calculation identified all species present at ≥0.01%. Using pH=6.3 as an example, 55.1% of cobalt is present as free Co2+, 28.6% is bound to a VFA (acetate, propionate or butyrate), and 13.1% is bound to histidine. The remaining 1.6% is distributed among Ala, Asp, Cys, Glu, Gly, Lys, Met, Ser, Thr, NH3 and OH. Similar results by ligand will be presented for Fe, Zn, Cu, Mn, Ca, His, Cys, and Glu. Data from these models confirm that glyphosate is a relatively weak chelator that should not have deleterious effects in the rumen.

APA, Harvard, Vancouver, ISO, and other styles

10

Al Sharif, Ohoud F., Laila M. Nhari, Reda M. El-Shishtawy, Mohie E. M. Zayed, and Abdullah M. Asiri. "AIE and reversible mechanofluorochromism characteristics of new imidazole-based donor–π–acceptor dyes." RSC Advances 12, no. 30 (2022): 19270–83. http://dx.doi.org/10.1039/d2ra01466a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Douglas, Colin, Tara Quinton, Ellinore Cabanban, Karen Black, and Ali Sadeghi-Khomami. "A Standardized Kit for a Chromogenic Modified Nijmegen-Bethesda Assay: Repeatability, Reproducibility, and Analytical Sensitivity." Blood 132, Supplement 1 (November 29, 2018): 1201. http://dx.doi.org/10.1182/blood-2018-99-119491.

Full text

Abstract:

Abstract Antibody-based inhibitor response to Factor VIII replacement therapy is one of the most common complications in the treatment of persons with hemophilia A (PwHA). Accordingly, accurate quantification of FVIII inhibitor antibody titer is essential in guiding patient treatment. Testing for FVIII inhibitors is not standardized; typically, FVIII inhibitor titers are measured using non-standardized LDTs (Laboratory Developed Tests). These LDTs vary in the processing of patient plasma, the reagents used to perform the assay, and the method of FVIII activity measurement. Here we report the development of a standardized set of reagents to perform a chromogenic modified Nijmegen-Bethesda assay (MNBA). The kit consists of imidazole-buffered pooled normal plasma (IB-PNP) with a consistent normal level of FVIII activity, and an imidazole-buffered bovine serum albumin solution (IB-BSA) as a diluent. Also included in the kit are a positive FVIII inhibitor plasma control (1.2 - 1.8 BU/mL) and an inhibitor-free negative plasma control. To perform the assay, test plasma was heat inactivated at 56 °C for 30 minutes to minimize residual FVIII activity. The inactivated plasma was then centrifuged (2700 x g,5 min.) and the supernatant used to make a series of two-fold serial dilutions with IB-BSA. The dilutions were each mixed with an equal volume of IB-PNP to form test mixes and incubated in a 37 °C water bath to allow time for the inhibitor antibodies from the patient plasma to inactivate FVIII in the IB-PNP. After two hours, the reaction was halted by cooling the test mixes in an ice bath. The FVIII activity of the test mixes was then measured using a Siemens FVIII Chromogenic Assay on a Siemens BCS XP analyzer. The residual FVIII activity of each test mix was calculated by comparing its FVIII activity to the activity of a control mix containing no test plasma (1:1 mixture of IB-BSA and IB-PNP). Here we report the use of this kit to perform a comprehensive study examining the repeatability, reproducibility, and analytical sensitivity of a chromogenic MNBA performed according to CLSI guidelines (CLSI EP05 and EP17). Inhibitor-negative and inhibitor-positive plasma from PwHA were combined to yield a panel of test plasmas at four different levels of inhibitor: below cutoff level (~0.3 BU/mL), low positive (~1.2 BU/mL), mid positive (~5 BU/mL) and a high positive (~8 BU/mL). To assess the repeatability of the assay, we measured each of these test plasmas using three lots of MNBA kit and one lot of FVIII chromogenic kit for a total of 240 titer determinations (3 lots × 20 days × 2 runs × 2 replicates). Inhibitor measurements of the panel of test plasmas showed within-lot precision of less than 10% (CV), and the kit controls were identified correctly each time. The reproducibility of the assay was determined in a study conducted across three different laboratories using different BCS XP analyzers and operators but the same panel of test plasmas. The limit of blank (LoB) and the limit of detection (LoD) of the assay were also determined using multiple low titer plasmas from unique donors. The assay system can reliably distinguish inhibitor titers as low as 0.2 BU/mL (LoD) in plasma from PwHA with no history of inhibitors. The chromogenic MNBA kit shows potential for labs seeking repeatable and reproducible FVIII inhibitor measurement that can otherwise vary significantly within or between labs. Standardization of reagents and protocol yields consistent results and is suitable for multi-center inhibitor studies in PwHA. Table Table. Disclosures No relevant conflicts of interest to declare.

APA, Harvard, Vancouver, ISO, and other styles

12

Muruganantham, Subramanian, Gunasekaran Velmurugan, Justin Jesuraj, Hassan Hafeez, Seung Yoon Ryu, Ponnambalam Venuvanalingam, and Rajalingam Renganathan. "Impact of tunable 2-(1H-indol-3-yl)acetonitrile based fluorophores towards optical, thermal and electroluminescence properties." RSC Advances 9, no. 25 (2019): 14544–57. http://dx.doi.org/10.1039/c8ra10448d.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Mao, Mao, Xiao-Lin Zhang, and Guo-Hua Wu. "Novel Imidazole Substituted Bodipy-Based Organic Sensitizers in Dye-Sensitized Solar Cells." International Journal of Photoenergy 2018 (2018): 1–9. http://dx.doi.org/10.1155/2018/2061472.

Full text

Abstract:

A comparative study on the photophysical, electrochemical properties and photovoltaic performances of pure imidazole dyes containing varying linker groups is done. Two new organic dyes containing 4,5-bis(4-methoxyphenyl)-1H-imidazole (BPI) unit as an electron donor, boron dipyrromethene (Bodipy) chromophore as a conjugate bridge, cyanoacetic acid as an electron acceptor, and phenylene (BPI-P) or thienyl (BPI-T) as a additional linker have been synthesized for fabricating dye-sensitized solar cells (DSSCs). A reference dye (DPI-T) with 6,9-dimethoxy-1H-phenanthro[9,10-d]imidazole as the donor has also been synthesized for comparison. The overall conversion efficiencies of 0.18%, 0.32%, and 1.28% were obtained for DSSCs based on BPI-P, BPI-T, and DPI-T, respectively. DPI-T was found to be more efficient than BPI-P and BPI-T because of its enhanced light harvesting efficiency and better coplanar geometry of the electronic structure.

APA, Harvard, Vancouver, ISO, and other styles

14

Yu, Pengfei, and Yin Xiao. "Non-Doped Deep-Blue OLEDs Based on Carbazole-π-Imidazole Derivatives." Materials 14, no. 9 (April 30, 2021): 2349. http://dx.doi.org/10.3390/ma14092349.

Full text

Abstract:

In this work, we designed and synthesized four bipolar blue-emitting materials with carbazole, imidazole, and biphenyl as donor, acceptor, and p bridge, respectively. The twisted phenylimidazole acceptor leads to a wider band-gap and hence deeper blue emission than the conjugated phenanthrimidazole acceptor. For the substituents on the carbazole donor, the t-butyl group could prevent the intramolecular charge transfer (ICT) process more effectively than the methoxy group. A non-doped deep-blue organic light-emitting diodes (OLED) is obtained with CIE coordinates of (0.159, 0.080), a maximum luminance of 11,364 cd/m2, and a maximum EQE of 4.43%.

APA, Harvard, Vancouver, ISO, and other styles

15

Feuerstein, Wolfram, Paul Varava, Farzaneh Fadaei-Tirani, Rosario Scopelliti, and Kay Severin. "Synthesis, structural characterization, and coordination chemistry of imidazole-based alkylidene ketenes." Chemical Communications 57, no. 87 (2021): 11509–12. http://dx.doi.org/10.1039/d1cc05161j.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Chang, Xin-Hong, Ying Zhao, Min-Le Han, Lu-Fang Ma, and Li-Ya Wang. "Five Cd(ii) coordination polymers based on 2,3′,5,5′-biphenyltetracarboxylic acid and N-donor coligands: syntheses, structures and fluorescent properties." CrystEngComm 16, no. 28 (2014): 6417–24. http://dx.doi.org/10.1039/c4ce00355a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Benkanoun, Aouaouche, Fadéla Balegroune, Achoura Guehria-Laidoudi, Slimane Dahaoui, and Claude Lecomte. "Comparative study between two new phthalate/imidazole Cobalt complexes." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C638. http://dx.doi.org/10.1107/s2053273314093619.

Full text

Abstract:

The main strategy for preparing novel multifunctional materials is based on self-assembly method which employs polydentate organic ligands containing N- or O-donor as building blocks. In this context, those ligands like imidazole or carboxylate groups are of special interest due to their good coordination ability and diverse coordination modes [1]. As a part of our investigations of extended structures with mixed ligands, new complexes [Co(Hipht)2(Im)2(H2O)2] and [Co(Tpht)(Im)3(H2O)2].H2O were obtained by direct method, then characterized by IR spectroscopy, TG/ATD and X-ray crystallography. In the compound [Co(Hipht)2(Im)2(H2O)2], CoII is located on a symmetry center, surrounded by two aqua ligands, two hydrogeno-isophthalate ligands and two imidazole molecules, where all ligands adopt monodentate mode. The complex's geometry consist of two intermolecular N-H...O bonds (2,157 Å and 2,630 Å) formed by one H atom of imidazole ligand and oxygen atoms of acid molecules evolving along two directions, giving rise to R24 (16) synthons. The interplanar distance of 3,718 Å between two parallel imidazole rings reveals the existence of Π-Π interactions. In the [Co(Tpht)(Im)3(H2O)2].H2O [2], the Co cation exhibits an octahedral coordination sphere, with two aqua, three N-coordinated imidazole ligands and one terephthalato dianion. The three independent imidazole groups and the single terephtalate dianion, all unidentate participate respectively as donor and acceptor in strong to moderate hydrogen bonds, and allow the recognition of supramolecular dimensionality. The backbone of the architecture is the helical hydrogen-bonded ladder running along b axis, composed of alternating R44(10) and R33(8) heterosynthons, which are developed in bicyclic sheets. Non covalent interactions play a significant role in this class of materials [3], in fact, extended hydrogen bonds networks associated to Π-Π interactions lead to 3D supramolecular architecture for the two complexes.

APA, Harvard, Vancouver, ISO, and other styles

18

Su, Feng, Jinyang Yu, Chengyong Zhou, Shaodong Li, Pengyi Ma, Xuhui Zhang, and Zhijun Wang. "Two ZnII-based MOFs constructed with biphenyl-2,2′,5,5′-tetracarboxylic acid and flexible N-donor ligands: syntheses, structures and properties." Acta Crystallographica Section C Structural Chemistry 76, no. 6 (May 13, 2020): 547–56. http://dx.doi.org/10.1107/s205322962000604x.

Full text

Abstract:

Two new Zn2+-based metal–organic frameworks (MOFs) based on biphenyl-2,2′,5,5′-tetracarboxylic acid, i.e. H4(o,m-bpta), and N-donor ligands, namely, poly[[(μ4-biphenyl-2,2′,5,5′-tetracarboxylato)bis{[1,3-phenylenebis(methylene)]bis(1H-imidazole)}dizinc(II)] dimethylformamide monosolvate dihydrate], {[Zn2(C16H6O8)(C14H14N4)2]·C3H7NO·2H2O} n or {[Zn2(o,m-bpta)(1,3-bimb)2]·C3H7NO·2H2O} n (1) {1,3-bimb = [1,3-phenylenebis(methylene)]bis(1H-imidazole)}, and poly[[(μ4-biphenyl-2,2′,5,5′-tetracarboxylato)bis{[1,4-phenylenebis(methylene)]bis(1H-imidazole)}dizinc(II)] monohydrate], {[Zn2(C16H6O8)(C14H14N4)2]·H2O} n or {[Zn2(o,m-bpta)(1,4-bimb)2]·H2O} n (2) {1,4-bimb = [1,4-phenylenebis(methylene)]bis(1H-imidazole)}, have been synthesized under solvothermal conditions. The complexes were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction and powder X-ray diffraction analysis. Structurally, the (o,m-bpta)4− ligands are fully deprotonated and combine with Zn2+ ions in μ4-coordination modes. Complex 1 is a (3,4)-connected porous network with honeycomb-like [Zn2(o,m-bpta)] n sheets formed by 4-connected (o,m-bpta)4− ligands. Complex 2 exhibits a (2,4)-connected network formed by 4-connected (o,m-bpta)4− ligands linking Zn2+ ions in left-handed helical chains. The cis-configured 1,3-bimb and 1,4-bimb ligands bridge Zn2+ ions to form multi-membered [Zn2(bimb)2] loops. Optically, the complexes show strong fluorescence and display larger red shifts compared to free H4(o,m-bpta). Complex 2 shows ferroelectric properties due to crystallizing in the C 2v polar point group.

APA, Harvard, Vancouver, ISO, and other styles

19

Mannu, Alberto, Maria Enrica Di Pietro, and Andrea Mele. "Band-Gap Energies of Choline Chloride and Triphenylmethylphosphoniumbromide-Based Systems." Molecules 25, no. 7 (March 25, 2020): 1495. http://dx.doi.org/10.3390/molecules25071495.

Full text

Abstract:

UV–VIS spectroscopy analysis of six mixtures containing choline chloride or triphenylmethylphosphonium bromide as the hydrogen bond acceptor (HBA) and different hydrogen bond donors (HBDs, nickel sulphate, imidazole, d-glucose, ethylene glycol, and glycerol) allowed to determine the indirect and direct band-gap energies through the Tauc plot method. Band-gap energies were compared to those relative to known choline chloride-containing deep band-gap systems. The measurements reported here confirmed the tendency of alcohols or Lewis acids to increment band-gap energy when employed as HBDs. Indirect band-gap energy of 3.74 eV was obtained in the case of the triphenylmethylphosphonium bromide/ethylene glycol system, which represents the smallest transition energy ever reported to date for such kind of systems.

APA, Harvard, Vancouver, ISO, and other styles

20

Navarro, M. Ángeles, Miguel A. Martín, José Rafael Ruiz, César Jiménez-Sanchidrián, Francisco J. Romero-Salguero, and Dolores Esquivel. "Improved Photocatalytic H2 Evolution by Cobaloxime-Tethered Imidazole-Functionalized Periodic Mesoporous Organosilica." Hydrogen 4, no. 1 (February 2, 2023): 120–32. http://dx.doi.org/10.3390/hydrogen4010008.

Full text

Abstract:

Molecular cobaloxime-based heterogeneous systems have attracted great interest during the last decades in light-driven hydrogen production. Here, we present a novel cobaloxime-tethered periodic mesoporous organosilica (PMO) hybrid (Im-EtPMO-Co) prepared through the immobilization of a molecular cobaloxime complex on the imidazole groups present in ethylene-bridged PMO. The successful assembly of a molecular cobaloxime catalyst via cobalt-imidazole axial ligation has been evidenced by several techniques, such as 13C NMR, Raman spectroscopy, ICP-MS, and XPS. The catalytic performance of Im-EtPMO-Co catalyst was essayed on the hydrogen evolution reaction (HER) under visible light in presence of a photosensitizer (Eosin Y) and an electron donor (TEOA). It showed an excellent hydrogen production of 95 mmol hydrogen at 2.5 h, which corresponded to a TON of 138. These results reflect an improved photocatalytic activity with respect to its homogenous counterpart [Co(dmgH)2(Im)Cl] as well as a previous cobaloxime-PMO system with pyridine axial ligation to the cobaloxime complex.

APA, Harvard, Vancouver, ISO, and other styles

21

Sahu, Sutapa, Yeasin Sikdar, Riya Bag, Javier Cerezo, José P. Cerón-Carrasco, and Sanchita Goswami. "Turn on Fluorescence Sensing of Zn2+ Based on Fused Isoindole-Imidazole Scaffold." Molecules 27, no. 9 (April 30, 2022): 2859. http://dx.doi.org/10.3390/molecules27092859.

Full text

Abstract:

Optical chemosensors caused a revolution in the field of sensing due to their high specificity, sensitivity, and fast detection features. Imidazole derivatives have offered promising features in the literature as they bear suitable donor/acceptor groups for the selective analytes in the skeleton. In this work, an isoindole-imidazole containing a Schiff base chemosensor (1-{3-[(2-Diethylamino-ethylimino)-methyl]-2-hydroxy-5-methyl-phenyl}-2H-imidazo[5,1-a]isoindole-3,5-dione) was designed and synthesized. The complete sensing phenomena have been investigated by means of UV-Vis, fluorescence, lifetime measurement, FT-IR, NMR and ESI-MS spectroscopic techniques. The optical properties of the synthesized ligand were investigated in 3:7 HEPES buffer:DMSO medium and found to be highly selective and sensitive toward Zn2+ ion through a fluorescence turn-on response with detection limit of 0.073 μm. Furthermore, this response is effective in gel form also. The competition studies reveal that the response of the probe for Zn2+ ion is unaffected by other relevant metal ions. The stoichiometric binding study was performed utilizing Job’s method which indicated a 1:1 sensor–Zn2+ ensemble. Computational calculations were performed to pinpoint the mechanism of sensing.

APA, Harvard, Vancouver, ISO, and other styles

22

Kenyotha, Kasama, Kingkaew Chayakul Chanapattharapol, Sirirath McCloskey, and Phongphan Jantaharn. "Water Based Synthesis of ZIF-8 Assisted by Hydrogen Bond Acceptors and Enhancement of CO2 Uptake by Solvent Assisted Ligand Exchange." Crystals 10, no. 7 (July 10, 2020): 599. http://dx.doi.org/10.3390/cryst10070599.

Full text

Abstract:

The aim of this work was to synthesize zeolitic imidazolate framework-8 (ZIF-8) by an alternative method and then modify the surface properties for enhancing the CO2 adsorption performance. The ZIF-8 was synthesized by a water based synthesis method using 2-methyl imidazole (2-MeIM) as a hydrogen bond donor and quaternary ammonium salts (QAS) as a hydrogen bond acceptor. The optimal synthesis conditions were investigated by varying (i) the order of precursor mixing during the synthesis process (ii) different QAS (tetrabutyl ammonium bromide (TBAB), tetraethyl ammonium bromide (TEAB) and trimethyl phenyl ammonium bromide (TMPAB)) and (iii) the ratio between 2-MeIM and QAS. The results show that the optimal synthesis condition was using TMPAB as the hydrogen bond acceptor with the ratio between 2-MeIM and TMPAB of 8:2 and in the order of first mixing both hydrogen bond donor and acceptor before adding Zn(NO3)2⋅6H2O solution. TMPAB can provide uniform size distribution with the smallest particle sizes of ZIF-8. This can be explained by the higher hydrogen bond strength between hydrogen bond donor (2-MeIM) and hydrogen bond acceptor (TMPAB) when compared with that of the rest of two QAS. The synthesized ZIF-8 was modified by solvent-assisted ligand exchange methods. The organic linker of ZIF-8 (2-MeIM) was exchanged by 2-aminobenzimidazole (2-NH2bZIM) and 2-phenylimidazole (2-PhIM). The CO2 uptake of modified ZIF-8 was enhanced upon exchanging with 2-NH2bZIM. The increase in CO2 uptake was due to an additional interaction between CO2 and exchanged imidazole linker and an increase in surface properties (higher surface area, pore size and pore volume).

APA, Harvard, Vancouver, ISO, and other styles

23

Karri, Ramesh, Ashish Chalana, Ranajit Das, Rakesh Kumar Rai, and Gouriprasanna Roy. "Cytoprotective effects of imidazole-based [S1] and [S2]-donor ligands against mercury toxicity: a bioinorganic approach." Metallomics 11, no. 1 (2019): 213–25. http://dx.doi.org/10.1039/c8mt00237a.

Full text

Abstract:

[S₂]-Donor ligands L2 and L3 showed remarkable ability to protect liver cell against HgCl₂induced toxicity and the strength of their efficacy is in the order of L3 > L2 > L1. Interestingly, 60% decrease of ROS production was observed in liver cells co-treated with HgCl₂and L3 in comparison to the cells treated with HgCl₂only.

APA, Harvard, Vancouver, ISO, and other styles

24

Rüther, Thomas, Nathalie Braussaud, and Kingsley J. Cavell. "Novel Chromium(III) Complexes Containing Imidazole-Based Chelate Ligands with Varying Donor Sets: Synthesis and Reactivity." Organometallics 20, no. 6 (March 2001): 1247–50. http://dx.doi.org/10.1021/om000846b.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Morita, Yasushi, Yosuke Yamamoto, Yumi Yakiyama, Tsuyoshi Murata, and Kazuhiro Nakasuji. "A Novel TTF-based Electron-donor with Imidazole-annelation Having Hydrogen-bonding and Proton-transfer Abilities." Chemistry Letters 37, no. 1 (January 5, 2008): 24–25. http://dx.doi.org/10.1246/cl.2008.24.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Zhang, Yumei, and Xudong Yu. "Colorimetric and electrochemical sensing for fluoride anion by ferrocenyl-based imidazole compound with electron donor–acceptor structure." Research on Chemical Intermediates 43, no. 2 (August 12, 2016): 1099–105. http://dx.doi.org/10.1007/s11164-016-2685-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Khalid, Muhammad, Muhammad Usman Khan, Iqra Shafiq, Riaz Hussain, Akbar Ali, Muhammad Imran, Ataualpa A. C. Braga, Muhammad Fayyaz ur Rehman, and Muhammad Safwan Akram. "Structural modulation of π-conjugated linkers in D–π–A dyes based on triphenylamine dicyanovinylene framework to explore the NLO properties." Royal Society Open Science 8, no. 8 (August 2021): 210570. http://dx.doi.org/10.1098/rsos.210570.

Full text

Abstract:

A donor–π–acceptor type series of Triphenylamine–dicyanovinylene-based chromophores ( DPMN1–DPMN11 ) was designed theoretically by the structural tailoring of π-linkers of experimentally synthesized molecules DTTh and DTTz to exploit changes in the optical properties and their nonlinear optical materials (NLO) behaviour. Density functional theory (DFT) computations were employed to understand the electronic structures, absorption spectra, charge transfer phenomena and the influence of these structural modifications on NLO properties. Interestingly, all investigated chromophores exhibited lower band gap (2.22–2.60 eV) with broad absorption spectra in the visible region, reflecting the remarkable NLO response. Furthermore, natural bond orbital (NBO) findings revealed a strong push–pull mechanism in DPMN1–DPMN11 as donor and π-conjugates exhibited positive, while all acceptors showed negative values. Examination of electronic transitions from donor to acceptor moieties via π-conjugated linkers revealed greater linear (〈 α 〉 = 526.536–641.756 a.u.) and nonlinear ( β tot = 51 313.8–314 412.661 a.u.) response. It was noted that the chromophores containing imidazole in the second p-linker expressed greater hyperpolarizability when compared with the ones containing pyrrole. This study reveals that by controlling the type of π-spacers, interesting metal-free NLO materials can be designed, which can be valuable for the hi-tech NLO applications.

APA, Harvard, Vancouver, ISO, and other styles

28

Danko, Martin, Filip Bureš, Jiří Kulhánek, and Pavol Hrdlovič. "Spectral Properties of Y-Shaped Donor-Acceptor Push-Pull Imidazole-based Fluorophores: Comparison between Solution and Polymer Matrices." Journal of Fluorescence 22, no. 4 (April 21, 2012): 1165–76. http://dx.doi.org/10.1007/s10895-012-1056-y.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Xu, Yipu, Zhifang Wu, Xiangzhe Zhao, and Xiangchun Li. "Two Cu(ii)-based coordination polymers: Crystal structures and treatment activity on periodontitis." Open Chemistry 19, no. 1 (January 1, 2021): 1287–93. http://dx.doi.org/10.1515/chem-2021-0119.

Full text

Abstract:

Abstract Two new Cu(ii)-based coordination polymers (CPs) with the chemical formulae of [CuL(bimmb)0.5] n (1, bimmb is 4-bis(imidazole-1-ylmethyl)benzene) and [CuL(bbibp)] n (2, bbibp is 4,4'-bis(benzoimidazo-1-yl)biphenyl) have been successfully prepared by the reaction of 3,3'-azodibenzoic acid (H2L) ligand and metal salt Cu(NO3)2·3H2O in the presence of different nitrogen-donor coligands. In the bioactive evaluation experiments, the treatment activity of the prepared CPs against periodontitis was examined. Enzyme-linked immunosorbent assay detection was used to test interleukin-18 (IL-18) and IL-6 contents released into the gingival crevicular fluid after the treatment of above CPs, and the real-time reverse transcription polymerase chain reaction was subsequently performed to measure the relative expression level of HmuY gene in the Porphyromonas gingivalis.

APA, Harvard, Vancouver, ISO, and other styles

30

Sabuzi, Federica, Alessia Coletti, Valeria Conte, Barbara Floris, and Pierluca Galloni. "Zinc porphyrin-anthraquinonylimidazole supramolecular dyads." Journal of Porphyrins and Phthalocyanines 24, no. 05n07 (May 2020): 850–59. http://dx.doi.org/10.1142/s1088424619501943.

Full text

Abstract:

In this work, the synthesis and spectroscopic characterization of new zinc porphyrin-anthraquinone dyads is proposed. In particular, electron donor units based on zinc meso-tetraphenylporphyrin (ZnTPP) and zinc octaethylporphyrin (ZnOEP) have been coupled with differently substituted anthraquinones as acceptors. The quinone moiety was properly functionalized with imidazole, thus ensuring porphyrin complexation through zinc ion coordination. Accordingly, absorption and emission measurements demonstrated that the coordination occurred, and calculated binding constants were in the range 6.6 [Formula: see text] 10[Formula: see text]–3.9 [Formula: see text] 10[Formula: see text] M[Formula: see text]. Transient absorption spectroscopy for ZnTPP and ZnOEP dyads demonstrated that the electron transfer occurred, with the formation of the corresponding charge separated state, ZnTPP[Formula: see text]-AQ. Moreover, in ZnOEP complexes, a strong correlation between the chain length and flexibility with the charge separated state lifetime was observed.

APA, Harvard, Vancouver, ISO, and other styles

31

Yu, Yue, Ruiyang Zhao, Haichao Liu, Shitong Zhang, Changjiang Zhou, Yu Gao, Weijun Li, and Bing Yang. "Highly efficient deep-blue light-emitting material based on V-Shaped donor-acceptor triphenylamine-phenanthro[9,10-d]imidazole molecule." Dyes and Pigments 180 (September 2020): 108511. http://dx.doi.org/10.1016/j.dyepig.2020.108511.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Bodedla, Govardhana Babu, Hongda Wang, Shuai Chang, Song Chen, Tao Chen, Jianzhang Zhao, Wai-Kwok Wong, and Xunjin Zhu. "β-Functionalized Imidazole-Fused Porphyrin-Donor-Based Dyes: Effect of π-Linker and Acceptor on Optoelectronic and Photovoltaic Properties." ChemistrySelect 3, no. 9 (March 1, 2018): 2558–64. http://dx.doi.org/10.1002/slct.201702652.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Xu, Zhong-Xuan, Chun-Yan Ou, and Chun-Xue Zhang. "3D semiconducting Co–MOFs based on 5-(hydroxymethyl)isophthalic acid and imidazole derivatives: syntheses and crystal structures." Acta Crystallographica Section C Structural Chemistry 76, no. 5 (April 17, 2020): 398–404. http://dx.doi.org/10.1107/s2053229620004970.

Full text

Abstract:

Two three-dimensional cobalt-based metal–organic frameworks with 5-(hydroxymethyl)isophthalic acid (H2HIPA), namely poly[[μ2-1,4-bis(2-methyl-1H-imidazol-1-yl)benzene-κ2 N 3:N 3′][μ2-5-(hydroxymethyl)isophthalato-κ2 O 1:O 3]cobalt(II)], [Co(C9H6O5)(C14H14N4)] n (1), and poly[tris[μ2-1,4-bis(1H-imidazol-1-yl)benzene-κ2 N 3:N 3′]bis[μ3-5-(hydroxymethyl)isophthalato-κ2 O 1:O 3:O 5]dicobalt(II)], [Co2(C9H6O5)2(C12H10N4)3] n (2), were synthesized under similar hydrothermal conditions. Single-crystal X-ray diffraction analyses revealed that 5-(hydroxymethyl)isophthalate (HIPA2−) and 1,4-bis(2-methyl-1H-imidazol-1-yl)benzene (1,4-BMIB) are simple linkers connecting cobalt centres to build a fourfold interpenetration dia framework in complex 1. However, complex 2 is a pillared-layer framework with a (3,6)-connected network constructed by 1,4-bis(1H-imidazol-1-yl)benzene (1,4-DIB) linkers, 3-connected HIPA2− ligands and 6-connected CoII centres. The above significant structural differences can be ascribed to the introduction of the different auxiliary N-donor ligands. Moreover, UV–Vis spectroscopy and Mott–Schottky measurements confirmed that complexes 1 and 2 are typical n-type semiconductors.

APA, Harvard, Vancouver, ISO, and other styles

34

Huang, Qiu-Ying, Yang Zhao, and Xiang-Ru Meng. "Syntheses, structures and characterization of isomorphous CoII and NiII coordination polymers based on 2-[(1H-imidazol-1-yl)methyl]-6-methyl-1H-benzimidazole and benzene-1,4-dicarboxylate." Acta Crystallographica Section C Structural Chemistry 73, no. 8 (July 31, 2017): 645–51. http://dx.doi.org/10.1107/s2053229617010877.

Full text

Abstract:

Careful choice of the organic ligands is one of the most important parameters in the rational design and synthesis of coordination polymers. Aromatic polycarboxylates have been widely used in the preparation of metal–organic polymers since they can utilize various coordination modes to form diverse structures and can act as hydrogen-bond acceptors and donors in the assembly of supramolecular structures. Nitrogen-heterocyclic organic compounds have also been used extensively as ligands for the construction of polymers with interesting structures. In the polymers catena-poly[[[diaquabis{2-[(1H-imidazol-1-yl)methyl]-6-methyl-1H-benzimidazole-κN 3}cobalt(II)]-μ2-benzene-1,4-dicarboxylato-κ2 O 1:O 4] dihydrate], {[Co(C8H4O4)(C12H11N4)2(H2O)2]·2H2O} n , (I), and catena-poly[[[diaquabis{2-[(1H-imidazol-1-yl)methyl]-6-methyl-1H-benzimidazole-κN 3}nickel(II)]-μ2-benzene-1,4-dicarboxylato-κ2 O 1:O 4] dihydrate], {[Ni(C8H4O4)(C12H11N4)2(H2O)2]·2H2O} n , (II), the CoII or NiII ion lies on an inversion centre and exhibits a slightly distorted octahedral coordination geometry, coordinated by two N atoms from two imidazole rings and four O atoms from two monodentate carboxylate groups and two water molecules. The dicarboxylate ligands bridge metal ions forming a polymeric chain. The 2-[(1H-imidazol-1-yl)methyl]-6-methyl-1H-benzimidazole ligands coordinate to the CoII or NiII centres in monodentate modes through an imidazole N atom and are pendant on opposite sides of the main chain. The two structures are isomorphous. In the crystal, the one-dimensional chains are further connected through O—H...O, O—H...N and N—H...O hydrogen bonds, leading to a three-dimensional supramolecular architecture. In addition, the IR spectroscopic properties, PXRD patterns, thermogravimetric behaviours and fluorescence properties of both polymers have been investigated.

APA, Harvard, Vancouver, ISO, and other styles

35

Yadav, Sagar B., Yogesh Erande, Chaitanya W. Ghanvatkar, and Nagaiyan Sekar. "Auxiliary hydroxy-phenanthro [9, 10-d] imidazole supported NLOphoric triphenylamine based donor-pi-acceptor compounds: Synthesis, solvatochromism and computational aspects." Journal of Luminescence 219 (March 2020): 116902. http://dx.doi.org/10.1016/j.jlumin.2019.116902.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Meng, Qing-Guo, Lin-Tong Wang, Ji-Tao Lu, Xin Wang, Wei Lu, and Zi-Yu Song. "Structures and Photoluminescence Properties of Four Cadmium(II) Coordination Polymers Synthesized by Rigid Ligands and N-Donor Ligands." Australian Journal of Chemistry 68, no. 5 (2015): 742. http://dx.doi.org/10.1071/ch14341.

Full text

Abstract:

Four metal–organic coordination polymers, [Cd2(dna)2(2,2′-bpy)2]n (1), {[Cd4(dna)4(im)3]·5H2O}n (2), {[Cd2(dna)2(4,4′-bpy)(H2O)2]·2EtOH}n (3), and {[Cd4(dna)4(1,3-dpp)4(H2O)4]·2H2O}n (4) (H2dna = 4,6-dimethyl-5-nitroisophthalic acid; 2,2′-bpy = 2,2′-bipyridine; im = imidazole; 4,4′-bpy = 4,4′-bipyridine; 1,3-dpp = 1,3-di(4-pyridyl)propane; and EtOH = ethanol, have been solvothermally synthesized and characterized. Compound 1 displays a one-dimensional (1D) ladder structure and the neighbouring ladders are further stabilized by π···π interactions to form a two-dimensional (2D) layer. Compound 2 forms a 2D layer based on infinite 1D [Cd2(COO)4]n chain and the im ligands act as terminal ligands, preventing expansion of the dimensionality. Compound 3 features a 2D 44-sql layer based on binuclear [Cd2(COO)4] secondary building units as 4-connected nodes, and is further linked to be an unusual three-dimensional (3D) supramolecular architecture by hydrogen bonds involving the coordinated water molecules, carboxylate groups, and lattice ethanol molecules. Compound 4 possesses a 2-fold interpenetrated dia net. The diverse structures and topologies of compounds 1–4 indicate that the N-containing ligands have significant effects on the formation of the final network structures. In addition, the thermal stabilities, structure comparison, and photoluminescence properties of the complexes have been investigated.

APA, Harvard, Vancouver, ISO, and other styles

37

Karthik, Vedhagiri, Vivek Gupta, and Ganapathi Anantharaman. "Synthesis of Imidazole-Based Functionalized Mesoionic Carbene Complexes of Palladium: Comparison of Donor Properties and Catalytic Activity toward Suzuki–Miyaura Coupling." Organometallics 33, no. 21 (October 17, 2014): 6218–22. http://dx.doi.org/10.1021/om5009023.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Guo, Wengang, Jianwei Wei, Yan Liu, and Can Li. "Construction of anti-1,2-diols bearing chiral tertiary alcohol moiety using free hydroxyacetone as aldol donor by imidazole-based prolineamide catalyst." Tetrahedron 70, no. 37 (September 2014): 6561–68. http://dx.doi.org/10.1016/j.tet.2014.07.015.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Yadav, Sagar B., Sumeet S. Sonvane, and Nagaiyan Sekar. "Novel blue-green emitting NLOphoric triphenylamine-imidazole based donor-π-acceptor compound: Solvatochromism, DFT, TD-DFT and non-linear optical studies." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 224 (January 2020): 117421. http://dx.doi.org/10.1016/j.saa.2019.117421.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Shanmugaraju, Sankarasekaran, Dipak Samanta, and Partha Sarathi Mukherjee. "Self-assembly of Ru4 and Ru8 assemblies by coordination using organometallic Ru(II)2 precursors: Synthesis, characterization and properties." Beilstein Journal of Organic Chemistry 8 (February 28, 2012): 313–22. http://dx.doi.org/10.3762/bjoc.8.34.

Full text

Abstract:

Coordination-driven self-assembly of binuclear half-sandwich p-cymene ruthenium(II) complexes [Ru2(μ-η4-C2O4)(MeOH)2(η6-p-cymene)2](O3SCF3)2 (1a) or [Ru2(μ-η4-N,N'-diphenyloxamidato)(MeOH)2(η6-p-cymene)2](O3SCF3)2 (1b) separately with an imidazole-based tetratopic donor L in methanol affords two tetranuclear metallamacrocycles 2a and 2b, respectively. Conversely, the similar combination of L with 2,5-dihydroxy-1,4-benzoquinonato (dhbq) bridged binuclear complex [Ru2(μ-η4-C6H2O4)(MeOH)2(η6-p-cymene)2](O3SCF3)2 (1c) in 1:2 molar ratio resulted in an octanuclear macrocyclic cage 2c. All the self-assembled macrocycles 2a–2c were isolated as their triflate salts in high yields and were characterized fully by multinuclear (1H, 13C and 19F) NMR, infrared (IR) and electrospray ionization mass spectrometry (ESIMS). In addition, the molecular structure of macrocycle 2a was established unequivocally by single-crystal X-ray diffraction analysis and adopts a tetranuclear rectangular geometry with the dimensions of 5.53 Å × 12.39 Å. Furthermore, the photo- and electrochemical properties of these newly synthesized assemblies have been studied by using UV–vis absorption and cyclic voltammetry analysis.

APA, Harvard, Vancouver, ISO, and other styles

41

Sabater, Paula, Fabiola Zapata, Bernardo López, Israel Fernández, Antonio Caballero, and Pedro Molina. "Enhancement of anion recognition exhibited by a zinc-imidazole-based ion-pair receptor composed of C–H hydrogen- and halogen-bond donor groups." Dalton Transactions 47, no. 44 (2018): 15941–47. http://dx.doi.org/10.1039/c8dt03736a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Guo, Wengang, Jianwei Wei, Yan Liu, and Can Li. "ChemInform Abstract: Construction of anti-1,2-Diols Bearing Chiral Tertiary Alcohol Moiety Using Free Hydroxyacetone as Aldol Donor by Imidazole-Based Prolineamide Catalyst." ChemInform 46, no. 5 (January 15, 2015): no. http://dx.doi.org/10.1002/chin.201505096.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Fu, Zi-Cheng, Cheng Mi, Yan Sun, Zhi Yang, Quan-Qing Xu, and Wen-Fu Fu. "An Unexpected Iron (II)-Based Homogeneous Catalytic System for Highly Efficient CO2-to-CO Conversion under Visible-Light Irradiation." Molecules 24, no. 10 (May 16, 2019): 1878. http://dx.doi.org/10.3390/molecules24101878.

Full text

Abstract:

We present two as-synthesized Fe(II)-based molecular catalysts with 1,10-phenanthroline (phen) ligands; Fe(phen)3Cl2 (1) and [Fe(phen)2(CH3CH2OH)Cl]Cl (2), and their robust catalytic properties for the conversion of CO2 to CO in DMF/TEOA (DMF = N,N’-dimethylformamide; TEOA = triethanolamine) solution containing Ru(bpy)32+ and BIH (1,3-dimethyl-2-phenyl-2,3- dihydro-1H-benzo-[d]-imidazole). High turnover numbers (TONs) of 19,376 were achieved with turnover frequencies (TOFs) of 3.07 s−1 for complex 1 (1.5 × 10−7 M). A quantum efficiency of 0.38% was observed after 5 h irradiated by 450 nm monochromatic light. The generation rate of CO2 and H2 were tuned by optimizing the experimental conditions, resulting in a high CO selectivity of 90%. The remarkable contribution of the photosensitizer to the total TONCO was found being 19.2% (as shown by tests under similar conditions without catalysts) when BIH was employed as a sacrificial electron donor. The product selectivity in complex 2 reached 95%, and the corresponding TONCO and TOFCO were 33,167 and 4.61 s−1 in the same concentration with complex 1 used as catalyst; respectively. This work provides guidance for future designs of simple, highly efficient and selective molecular catalytic systems that facilitate carbon-neutral solar-to-fuel conversion processes

APA, Harvard, Vancouver, ISO, and other styles

44

Li, Hui-Hong, Ratnava Maitra, Ya-Ting Kuo, Jie-Hong Chen, Ching-Han Hu, and Hon Man Lee. "A tridentate CNO-donor palladium(II) complex as efficient catalyst for direct C―H arylation: Application in preparation of imidazole-based push-pull chromophores." Applied Organometallic Chemistry 32, no. 1 (August 25, 2017): e3956. http://dx.doi.org/10.1002/aoc.3956.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Priyadarsini, R., and Anandhan Menaka. "DESIGN AND SYNTHESIS OF SOME NEWER IMIDAZOLYL HETEROCYCLES AS POTENT BTK INHIBITORS FOR THE TREATMENT OF RHEUMATOID ARTHRITIS." International Journal of Current Pharmaceutical Research 9, no. 3 (May 5, 2017): 80. http://dx.doi.org/10.22159/ijcpr.2017.v9i3.19668.

Full text

Abstract:

Objective: The rheumatoid arthritis as a global health problem over the past few decades, Emphasizes the need for discovery of new therapeutic disease modifying anti-rheumatoid Arthritis drugs (DMARD’s). Bruton’s tyrosine kinase (BTK) is a cytoplasmic, non-receptor, tyrosine kinase which is expressed in most of the hematopoietic cells and plays an important role in the development, differentiation and proliferation of B-lineage cells, thus making BTK an efficient therapeutic target for the treatment of rheumatoid arthritis. This prompted us to synthesise a novel series of Imidazolyl Heterocycles as potent BTK (Bruton’s Tyrosine Kinase) inhibitors with alleged Anti-Rheumatoid Arthritis properties. Methods: Newer BTK inhibitors containing one hydrogen bond acceptor (HBA), one hydrogen bond donor (HBD) and three hydrophobic features based on that pharmacophore model for BTK were designed. The designed compounds were sorted by applying ADMET properties, Lipinski rule of five, molecular docking and Novelty prediction to refine the designed ligands. Finally, different five compounds containing Imidazole as the heterocyclic nucleus have been synthesized and characterized by different analytical methods like Chromatographic data, Elemental analysis and Spectral studies by IR, 1H NMR, 13C NMR, GC-MS. Molecular docking studies were performed against BTK using GLIDE 10.2. Results: Several important hydrogen bonds with BTK were revealed, which include the gatekeeper residue Glu475 and Met477 at the hinge region. Conclusion: Overall, this study suggests that the proposed ligands are found to be more effective BTK inhibitor as Anti-Rheumatoid arthritis agents.

APA, Harvard, Vancouver, ISO, and other styles

46

Pacheco, Mario, Javier González-Platas, Carlos Kremer, Miguel Julve, Francesc Lloret, and Alicia Cuevas. "Novel Mononuclear Tetrabromonitrosylrhenate(II) Complexes Containing Azole-Type Ligands: Magnetostructural Characterization through Hirshfeld Surfaces Analysis." Crystals 13, no. 4 (April 11, 2023): 658. http://dx.doi.org/10.3390/cryst13040658.

Full text

Abstract:

Our research group has made incursions into the scarcely known coordination chemistry of rhenium(II). The literature shows that Re(II) mononuclear complexes are attractive in molecular magnetism due to high magnetic anisotropy because of a significant spin-orbit coupling, making them a potential source for new molecule-based magnets. In this work, we present the preparation of four novel Re(II) compounds of general formula NBu4[Re(NO)Br4(L)] [NBu4+ = tetra-n-butylammonium: L = imidazole (1), pyrazole (2), 1,2,4-triazole (3) and 1H-tetrazole (4)]. The four compounds were fully characterized by single-crystal X-ray diffraction, infrared spectroscopy, and cryomagnetic measurements in the temperature range of 1.8–300 K. Their crystal structures consist of mononuclear [Re(NO)Br4(L)]− complex anions and NBu4+ cations. Each Re(II) ion is six-coordinate with a linear nitrosyl group and one monodentate nitrogen-donor (L), which are trans-positioned, plus four bromide groups, building a tetragonally distorted octahedral surrounding. The inter-anionic contacts were thoroughly analyzed using Hirshfeld surface analyses (plots over the dnorm, shape index, and 2D fingerprints). Cryomagnetic measurements show that these complexes behave as quasi-magnetically isolated spin doublets with weak antiferromagnetic interactions at low temperatures. The magnetic behavior of Re(II) was modeled by the influence of the ligand field, tetragonal distortion, spin-orbit coupling, and covalence effects. In addition, the antiferromagnetic exchange coupling was correlated to the nature of the intermolecular interactions.

APA, Harvard, Vancouver, ISO, and other styles

47

Jeliński, Tomasz, Maciej Kubsik, and Piotr Cysewski. "Application of the Solute–Solvent Intermolecular Interactions as Indicator of Caffeine Solubility in Aqueous Binary Aprotic and Proton Acceptor Solvents: Measurements and Quantum Chemistry Computations." Materials 15, no. 7 (March 27, 2022): 2472. http://dx.doi.org/10.3390/ma15072472.

Full text

Abstract:

The solubility of caffeine in aqueous binary mixtures was measured in five aprotic proton acceptor solvents (APAS) including dimethyl sulfoxide, dimethylformamide, 1,4-dioxane, acetonitrile, and acetone. The whole range of concentrations was studied in four temperatures between 25 °C and 40 °C. All systems exhibit a strong cosolvency effect resulting in non-monotonous solubility trends with changes of the mixture composition and showing the highest solubility at unimolar proportions of organic solvent and water. The observed solubility trends were interpreted based on the values of caffeine affinities toward homo- and hetero-molecular pairs formation, determined on an advanced quantum chemistry level including electron correlation and correction for vibrational zero-point energy. It was found that caffeine can act as a donor in pairs formation with all considered aprotic solvents using the hydrogen atom attached to the carbon in the imidazole ring. The computed values of Gibbs free energies of intermolecular pairs formation were further utilized for exploring the possibility of using them as potential solubility prognostics. A semi-quantitative relationship (R2 = 0.78) between caffeine affinities and the measured solubility values was found, which was used for screening for new greener solvents. Based on the values of the environmental index (EI), four morpholine analogs were considered and corresponding caffeine affinities were computed. It was found that the same solute–solvent structural motif stabilizes hetero-molecular pairs suggesting their potential applicability as greener replacers of traditional aprotic proton acceptor solvents. This hypothesis was confirmed by additional caffeine solubility measurements in 4-formylmorpholine. This solvent happened to be even more efficient compared to DMSO and the obtained solubility profile follows the cosolvency pattern observed for other aprotic proton acceptor solvents.

APA, Harvard, Vancouver, ISO, and other styles

48

Keshtov, Muhammed L., Sergei A. Kuklin, Ilya E. Ostapov, Elena E. Makhaeva, Rakesh Suthar, Chuandong Dou, and Ganesh D. Sharma. "New High‐Bandgap 8,10‐Dihydro‐9 H ‐Bistieno[2′,3′:7.8;3″,2″:5.6]Naphtho[2,3‐d] Imidazole‐9‐One‐Based Donor–Acceptor Copolymers for Nonfullerene Polymer Solar Cells." Energy Technology 8, no. 10 (September 10, 2020): 2000611. http://dx.doi.org/10.1002/ente.202000611.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Patel1, Ankita S., Ujashkumar A. Shah2, Hirak V. Joshi, Jayvadan K. Patel2, Vijay K. Patel1, Jignasa Savjani3, and Kailash kumar Choudhary4. "Design, synthesis and biological screening of novel heterocyclic ring derivatives as antibacterial agents." Journal of medical pharmaceutical and allied sciences 11, no. 2 (March 30, 2022): 4650–56. http://dx.doi.org/10.55522/jmpas.v11i2.2623.

Full text

Abstract:

For a long time, numerous attempts are being made by researchers to discover and develop new antimicrobial agents based on synthetic compounds and medicinal plants. These attempts were forced due to increasing rate of microbial resistance. In the present study, it has been discussed that the synthesis of various dihydropyrimidine fused with benzimidazole moiety. In which o-phenylenediamine and chloroacetic acid react in acidic medium by nucleophilic addition reaction to form 2-chloro methyl Benzimidazole. (1). The substituted Chalcone (2) was synthesized by a claisan-schmidt condensation reaction. The condensation of an aromatic aldehyde with aromatic ketone having α- hydrogen in presence of a strong base to form α,β-unsaturated ketone i.e Chalcone is form. The substituted Chalcone react with thiourea by Michael reaction. It is also called 1,4 addition reaction. In which thiourea act as nucleophile attack on 4-positon of the α,β-unsaturated ketone and keto-enol tautomerism occurs and 4- substitutedphenyl-6-substitutedphenyl-4,5-dihydropyrimidine-2- thiol . (3). Benzimidazole (1) fused with substituted dihydropyrimidine-2-thiol (3) in presence of THF and form 2-((4-substituted phenyl-6-substituted phenyl pyrimidine-2-ylthio)methyl)-1H-benzo[d]imidazole. (4). The synthesized compounds APUS1 – APUS21 were assigned by its spectral data (IR, NMR and mass spectra). The synthesized compounds have been tested for their antibacterial activity against Gram (+) bacteria (S. aureus) , (B.subtilis) and Gram (-) bacteria (E.coli ) by agar diffusion method. Compound having electron withdrawing group show significant activity and having electron donor group show moderate activity. Keywords: Antibacterial activity, Molecular docking, Dihydropyrimidine, Benzimidazole.

APA, Harvard, Vancouver, ISO, and other styles

50

Wu, Xue-Qian, Min-Le Han, Guo-Wang Xu, Bin Liu, Dong-Sheng Li, and Jian Zhang. "A 3D Ni(II)-MOF with frl topology based on 2-(1-imidazole)-1-hydroxyl-1,1′-ethylidenediphosphonic acid and N,N′-donor co-ligand: Synthesis, structure and magnetic property." Inorganic Chemistry Communications 58 (August 2015): 60–63. http://dx.doi.org/10.1016/j.inoche.2015.06.004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Imidazole-based donors'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles