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Journal articles on the topic 'Pyrazole Based Ligand'

Author: Grafiati

Published: 7 September 2023

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1

Syahputri, Yulian, Sutanto Sutanto, and Riza Shabrina Zamzani. "Hg (II) and Cd (II) Heavy Metal Ions Detection Based On Fluorescence Using Zn (II) Metal Ion Complex with Pyrazoline Derivatives Ligand." Helium: Journal of Science and Applied Chemistry 2, no. 1 (June 30, 2022): 1–6. http://dx.doi.org/10.33751/helium.v2i1.5407.

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Pyrazoline derivatives can be used as ligands because they have photophysical properties and can chelate metal ions which cause very strong absorption, emission and have a fluorescence properties. Therefore, in recent years, pyrazoline ligands and their derivatives have been widely used for chemosensors. This research aims to detect fluorescence-based heavy metal ions Hg2+ and Cd2+ using a metal ion complex compound Zn2+ with pyrazoline derivative ligand. The research was started by synthesizing pyrazoline-derived ligands, then synthesizing complex compounds. Complex compounds were characterized using Fourier Transform Infra Red (FTIR), UV-Vis Spectrophotometer, and Spectrofluorometer. Then, a fluorescence study was carried out to determine the type of fluorosensor for complex compounds with the addition of heavy metal ions Cd2+ and Hg2+. The last stage is UV-Vis spectroscopy study on the addition of heavy metal ions Hg2+ and Cd2+. Pyrazoline derivative ligand obtained as para-di-2-(1-phenyl-3-pyridyl-4,5-dihydro-1H-pyrazole-5-yl)benzene is a yellow solid. The metal ion complex compound Zn2+ with pyrazolin derivative ligand is a brown colored compound, has a yield of 45 % and a melting point is 245 oC. The FTIR spectrum showed the presence of functional groups such as amine, C-H aromatic, C=N, C=C aromatic, C-N, Zn-N and Zn-Cl. Analysis with UV-Vis spectrophotometer showed that there was a shift in the maximum wavelength from the ligand to the Zn(II)-ligand complex, namely 240 nm to 246 nm and 363 nm with molar absorptivity values (log ) of 4.56 and 4.28, respectively. For fluorescence analysis, two absorbance peaks were obtained, namely at a wavelength of 370 nm with an intensity of 3644 a.u and 478 m at 8216 a.u. The results of fluorescence chemosensor studies on the addition of heavy metal ions Hg2+ and Cd2+ showed that the metal ion complex compound Zn2+ with pyrazoline-derived ligands can detect heavy metal ions Hg2+ and Cd2+ with a turn-on type.

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2

Hajra, Tanima, Jitendra K. Bera, and Vadapalli Chandrasekhar. "Cyclometalated Ir(III) Complexes Containing Pyrazole/Pyrazine Carboxylate Ligands." Australian Journal of Chemistry 64, no. 5 (2011): 561. http://dx.doi.org/10.1071/ch11049.

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Two cyclometalated Ir(iii) complexes using 2-phenylpyridine (ppy-H) as the cyclometalating ligand, and pyrazole-3-carboxylic acid (prca-H) and pyrazine 3,5-dicarboxylic acid (pzdca-H2) as ancillary ligands; were synthesized from the chloro-bridged dimer precursor [{(ppy)2Ir}2(μ-Cl)2]. The title compounds [Ir(ppy)2(prca)] (1) and [{Ir(ppy)2}2(pzdca)] (2) are monomeric and dimeric neutral Ir(iii) complexes, respectively. Their electrochemical and photophysical properties were examined. They exhibit metal-based oxidations and ligand-based reductions. These complexes exhibit emission in the blue-green region with lifetimes in the micro-second range at room temperature. The nature of the emission spectra indicates differences in the origin of emission in these two compounds.

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3

Guerrero, Miguel, Lourdes Rivas, Teresa Calvet, Mercè Font-Bardia, and Josefina Pons. "ZnII Complexes Based on Hybrid N-Pyrazole, N′-imine Ligands: Synthesis, X-Ray Crystal Structure, NMR Characterisation, and 3D Supramolecular Properties." Australian Journal of Chemistry 68, no. 5 (2015): 749. http://dx.doi.org/10.1071/ch14344.

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The present report is on the synthesis of two new 3-imine-3,5-dimethylpyrazole ligands, N-[3-(3,5-dimethyl-1H-pyrazol-1-yl)propylidene]ethylamine (L1) and N-[3-(3,5-dimethyl-1H-pyrazol-1-yl)propylidene]propylamine (L2). These ligands form molecular complexes with the formula [ZnCl2(L)] (L = L1 (1) and L2 (2)) when the reacting with ZnCl2 in a metal (M)/ligand (L) ratio of 1 : 1. These new ZnII complexes have been characterised by elemental analyses, conductivity measurements, mass spectrometry, and infrared, 1H and 13C{1H} NMR spectroscopy techniques. The two crystalline structures of complexes 1 and 2 have been solved by X-ray diffraction methods. Finally, we have studied the self-assembly three-dimensional supramolecular structure through different intra- and intermolecular contacts. The application of these ZnII complexes in supramolecular crystal engineering is interesting due to (1) the easy preparation and the high efficiency of this system and (2) the different bonding properties of the heteroatoms (N-pyrazole vs N-imine) present in the structure of the ligands.

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4

Altmann, Philipp J., Christian Jandl, and Alexander Pöthig. "Introducing a pyrazole/imidazole based hybrid cyclophane: a hydrogen bond sensor and binucleating ligand precursor." Dalton Transactions 44, no. 25 (2015): 11278–81. http://dx.doi.org/10.1039/c5dt01775k.

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5

Titi, Abderrahim, Kaoutar Zaidi, Abdullah Y. A. Alzahrani, Mohamed El Kodadi, El Bekkaye Yousfi, Anna Moliterni, Belkheir Hammouti, Rachid Touzani, and Mohamed Abboud. "New In Situ Catalysts Based on Nitro Functional Pyrazole Derivatives and Copper (II) Salts for Promoting Oxidation of Catechol to o-Quinone." Catalysts 13, no. 1 (January 10, 2023): 162. http://dx.doi.org/10.3390/catal13010162.

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Herein, new substituted ligands based on pyrazole (L1–L4) were synthesized via a one-step by condensing (1H-pyrazole-1-yl) methanol with different primary amine compounds. The present work utilized the catalytic properties of the in situ complexes formed by these ligands with various copper (II) salts viz. Cu(CH3COO)2, CuSO4, CuCl2, and Cu(NO3)2 for the oxidation of catechol to o-quinone. The studies showed that the catalytic activities depend on the nature and concentration of the ligand, the nature of the counterion, and the solvent. It was observed that the complex formed by L2 and Cu(CH3COO)2 exhibited good catalytic activity in methanol with Vmax of 41.67 µmol L−1 min−1 and Km of 0.02 mol L−1.

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6

Yousri, Amal, Ayman El-Faham, Matti Haukka, Mohammed Salah Ayoup, Magda M. F. Ismail, Nagwan G. El Menofy, Saied M. Soliman, Lars Öhrström, Assem Barakat, and Morsy A. M. Abu-Youssef. "A Novel Na(I) Coordination Complex with s-Triazine Pincer Ligand: Synthesis, X-ray Structure, Hirshfeld Analysis, and Antimicrobial Activity." Crystals 13, no. 6 (May 29, 2023): 890. http://dx.doi.org/10.3390/cryst13060890.

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The pincer ligand 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (bpmt) was used to synthesize the novel [Na(bpmt)2][AuCl4] complex through the self-assembly method. In this complex, the Na(I) ion is hexa-coordinated with two tridentate N-pincer ligands (bpmt). The two bpmt ligand units are meridionally coordinated to Na(I) via one short Na-N(s-triazine) and two slightly longer Na-N(pyrazole) bonds, resulting in a distorted octahedral geometry around the Na(I) ion. In the coordinated bpmt ligand, the s-triazine core is not found to be coplanar with the two pyrazole moieties. Additionally, the two bpmt units are strongly twisted from one another by 64.94°. Based on Hirshfeld investigations, the H···H (53.4%) interactions have a significant role in controlling the supramolecular arrangement of the [Na(bpmt)2][AuCl4] complex. In addition, the Cl···H (12.2%), C···H (11.5%), N···H (9.3%), and O···H (4.9%) interactions are significant. Antimicrobial investigations revealed that the [Na(bpmt)2][AuCl4] complex has promising antibacterial and antifungal activities. The [Na(bpmt)2][AuCl4] complex showed enhanced antibacterial activity for the majority of the studied gram-positive and gram-negative bacteria compared to the free bpmt (MIC = 62.5–125 µg/mL vs. MIC = 62.5–500 µg/mL, respectively) and Amoxicillin (MIC > 500 µg/mL) as a positive control. Additionally, the [Na(bpmt)2][AuCl4] complex had better antifungal efficacy (MIC = 125 µg/mL) against C. albicans compared to bpmt (MIC = 500 µg/mL).

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7

Singh, Avineesh, and Harish Rajak. "STRUCTURAL EXPLORATION AND PHARMACOPHORIC INVESTIGATION OF PYRAZOLE BASED ANALOGS AS NOVEL HISTONE DEACETYLASE 1 INHIBITOR USING COMBINATORIAL STUDIES." International Journal of Pharmacy and Pharmaceutical Sciences 10, no. 3 (March 1, 2018): 90. http://dx.doi.org/10.22159/ijpps.2018v10i3.22735.

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Objective: Histone deacetylase inhibitors (HDACi) have four essential pharmacophores as cap group, connecting unit, a linker moiety and zinc binding group for their anticancer and histone deacetylase (HDAC) inhibition activity. On the basis of this fact, the objective of this research was to evaluate the exact role of pyrazole nucleus as connecting unit and its role in the development of newer HDACi.Methods: Ligand and structure-based computer-aided drug design strategies such as pharmacophore and atom based 3D QSAR modelling, molecular docking and energetic based pharmacophore mapping have been frequently applied to design newer analogs in a precise manner. Herein, we have applied these combinatorial approaches to develop the structure-activity correlation among novel pyrazole-based derivatives.Results: the Pharmacophore-based 3D-QSAR model was developed employing Phase module and e-pharmacophore on compound 1. This 3D-QSAR model provides fruitful information regarding favourable and unfavourable substitution on pyrazole-based analogs for HDAC1 inhibition activity. Molecular docking studies indicated that all the pyrazole derivatives bind with HDAC1 proteins and showed critical hydrophobic interaction with 5ICN and 4BKX HDAC1 proteins.Conclusion: The outcome of the present research work clearly indicated that pyrazole nucleus added an essential hydrophobic feature in cap group and could be employed to design the ligand molecules more accurately.

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8

Lancheros, Andrés, Subhadip Goswami, Mohammad Rasel Mian, Xuan Zhang, Ximena Zarate, Eduardo Schott, Omar K. Farha, and Joseph T. Hupp. "Modulation of CO2 adsorption in novel pillar-layered MOFs based on carboxylate–pyrazole flexible linker." Dalton Transactions 50, no. 8 (2021): 2880–90. http://dx.doi.org/10.1039/d0dt03166f.

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9

Lin, Chen-Lan, Yan-Fei Chen, Li-Juan Qiu, Binglong Zhu, Xin Wang, Shi-Peng Luo, Wenyan Shi, Ting-Hai Yang, and Wu Lei. "Synthesis, structure and photocatalytic properties of coordination polymers based on pyrazole carboxylic acid ligands." CrystEngComm 22, no. 41 (2020): 6847–55. http://dx.doi.org/10.1039/d0ce01054e.

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10

BAI, FU-QUAN, TAO LIU, XIN ZHOU, JIAN-PO ZHANG, and HONG-XING ZHANG. "THEORETICAL COMPUTATIONAL STUDIES ON ELECTRONIC STRUCTURES, SPECTROSCOPIC PROPERTIES AND NITROGEN HETEROATOM EFFECT OF A SPECIES OF ASYMMETRICAL DIIMINE LIGAND PLATINUM(II) COMPLEXES." Journal of Theoretical and Computational Chemistry 08, no. 04 (August 2009): 603–13. http://dx.doi.org/10.1142/s0219633609004952.

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Electronic structures and spectroscopic properties of a series of platinum(II) complexes based on the C-linked asymmetrical diimine ligand (2-pyridyl-pyrazole (1), 2-pyridyl-1,2,4-triazole (2), 2-pyridyl-tetrazole (3), 2-pyrazine-pyrazole (4) have been studied by the time-dependent density functional theory calculations with polarizable continuum model. The ground- and excited-state structures were optimized by the density functional theory and single-excitation configuration interaction methods, respectively. The calculated structures and spectroscopic properties are in agreement with the corresponding experimental data. The results of the spectroscopic investigations revealed that the lowest-energy absorptions have1,3metal-to-ligand charge transfer (MLCT)/1,3single ligand centered charge transfer (ILCT) mixing characters. The highest-occupied molecular orbitals (HOMOs) of 1–4 are composed of Pt ( d yz) and azole, while the lowest-unoccupied molecular orbitals (LUMOs) are mainly localized upon the pyridyl-azolate ligand (70% on the pyridine segment). From 1 to 3, the molecular orbital (MO) energies of HOMO and LUMO are decreased and the HOMO energies are changed more remarkably. This is caused by that the conjugation of the azolate segment of the ligand are enhanced through introducing more N heteroatoms into this segment. As a result of MO energy change, the lowest-energy absorptions are blue-shifted in the order 1 < 2 < 3. With the replacement of pyridyl by pyrazine, the HOMO energy of 4 is comparable to 1, but the LUMO energy is decreased by 0.8 eV, and the lowest-energy absorptions are red-shifted to 2.36 eV. Otherwise, the phosphorescent emissions of these complexes have the 3MLCT/3ILCT characters, and should originate from the lowest-energy absorptions. The emissions of 1–4 are red-shifted in the order 3 < 2 < 1 < 4. The heteroatom effect is suitable for tuning the spectra of this kind of materials.

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11

Sheng, Kai, Bao-Qian Ji, Lei Feng, Yan-Min Su, Marko Jagodič, Zvonko Jagličić, and Di Sun. "A rod-like hexanuclear nickel cluster based on a bi(pyrazole-alcohol) ligand: structure, electrospray ionization mass spectrometry, magnetism and photocurrent response." New Journal of Chemistry 44, no. 17 (2020): 7152–57. http://dx.doi.org/10.1039/d0nj00959h.

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12

Dias, H. V. Rasika. "Polyfluorinated ligand-supported organometallic complexes of copper, silver, and gold." Pure and Applied Chemistry 82, no. 3 (February 14, 2010): 649–56. http://dx.doi.org/10.1351/pac-con-09-10-19.

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The tris(pyrazolyl)borate [HB(3,5-(CF3)2Pz)3]− prepared using highly fluorinated 3,5-bis(trifluoromethyl)pyrazole and BH4− is an excellent supporting ligand for the stabilization of a number of rare organometallic complexes of coinage metals. For example, it has enabled the isolation of Cu(I), Ag(I), and Au(I) complexes of CO and ethylene as crystalline solids. Syntheses, spectroscopic and structural features, and properties of [HB(3,5-(CF3)2Pz)3]ML (M = Cu, Ag, Au; L = CO, C2H4) are the main focus of this discussion. Several metal adducts based on the tris(triazolyl)borate [HB(3,5-(CF3)2Tz)3]− supporting ligand as well as the cationic, coinage metal multi-alkene complexes containing the [SbF6]− counterion are also discussed.

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13

Nyamato, George S., Stephen O. Ojwach, and Matthew P. Akerman. "Packing forces in dichloridobis(3,5-diphenyl-1H-pyrazole-κN2)cobalt(II) dichloromethane hemisolvate." Acta Crystallographica Section C Structural Chemistry 70, no. 8 (July 19, 2014): 780–83. http://dx.doi.org/10.1107/s2053229614015411.

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The title compound, [CoCl2(C15H12N2)2]·0.5CH2Cl2, was crystallized from a binary mixture of dichloromethane and hexane and a dimeric supramolecular structure was isolated. The CoIIcentre exhibits a distorted tetrahedral geometry, with two independent pyrazole-based ligands occupying two coordination sites and two chloride ligands occupying the third and fourth coordination sites. The supramolecular structure is supported by complementary hydrogen bonding between the pyrazole NH group and the chloride ligand of an adjacent molecule. This hydrogen-bonding motif yields a ten-membered hydrogen-bonded ring. Density functional theory (DFT) simulations at the PBE/6-311G level of theory were used to probe the solid-state structure. These simulations suggest that the chelate undergoes a degree of conformational distortion from the lowest-energy geometry to allow for optimal hydrogen bonding in the solid state.

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14

Bennani, Fatima Ezzahra, Khalid Karrouchi, Latifa Doudach, Mario Scrima, Noor Rahman, Luca Rastrelli, Trina Ekawati Tallei, Christopher E. Rudd, My El Abbes Faouzi, and M’hammed Ansar. "In Silico Identification of Promising New Pyrazole Derivative-Based Small Molecules for Modulating CRMP2, C-RAF, CYP17, VEGFR, C-KIT, and HDAC—Application towards Cancer Therapeutics." Current Issues in Molecular Biology 44, no. 11 (October 31, 2022): 5312–51. http://dx.doi.org/10.3390/cimb44110361.

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Despite continual efforts being made with multiple clinical studies and deploying cutting-edge diagnostic tools and technologies, the discovery of new cancer therapies remains of severe worldwide concern. Multiple drug resistance has also emerged in several cancer cell types, leaving them unresponsive to the many cancer treatments. Such a condition always prompts the development of next-generation cancer therapies that have a better chance of inhibiting selective target macromolecules with less toxicity. Therefore, in the present study, extensive computational approaches were implemented combining molecular docking and dynamic simulation studies for identifying potent pyrazole-based inhibitors or modulators for CRMP2, C-RAF, CYP17, c-KIT, VEGFR, and HDAC proteins. All of these proteins are in some way linked to the development of numerous forms of cancer, including breast, liver, prostate, kidney, and stomach cancers. In order to identify potential compounds, 63 in-house synthesized pyrazole-derivative compounds were docked with each selected protein. In addition, single or multiple standard drug compounds of each protein were also considered for docking analyses and their results used for comparison purposes. Afterward, based on the binding affinity and interaction profile of pyrazole compounds of each protein, potentially strong compounds were filtered out and further subjected to 1000 ns MD simulation analyses. Analyzing parameters such as RMSD, RMSF, RoG and protein–ligand contact maps were derived from trajectories of simulated protein–ligand complexes. All these parameters turned out to be satisfactory and within the acceptable range to support the structural integrity and interaction stability of the protein–ligand complexes in dynamic state. Comprehensive computational analyses suggested that a few identified pyrazole compounds, such as M33, M36, M72, and M76, could be potential inhibitors or modulators for HDAC, C-RAF, CYP72 and VEGFR proteins, respectively. Another pyrazole compound, M74, turned out to be a very promising dual inhibitor/modulator for CRMP2 and c-KIT proteins. However, more extensive study may be required for further optimization of the selected chemical framework of pyrazole derivatives to yield improved inhibitory activity against each studied protein receptor.

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Rani, Rekha, Umesh Kumar, Deepak Kumar, Siteshwar Pd Yadav, Arjun Kr Sinha, and S. Sharma. "Spectroscopic, Thermal and Antimicrobial Study of Some Transition Metal(II) Complexes of β-Diketones." Asian Journal of Chemistry 32, no. 12 (2020): 3173–78. http://dx.doi.org/10.14233/ajchem.2020.22911.

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A novel heterocyclic based β-diketone has been synthesized by the condensation of pyrazole-1-acetylchloride and sodium acetophenone. The product 1-phenyl-4-(pyrazole-1-yl)butane- 1,3-dione has been used for complexation with Mn(II), Fe(II) and Co(II) metal ions. The ligand β-diketone is found to exist in keto-enol tautomeric forms. The comparision of infrared spectra of complexes clearly indicates the coordination of the ligand from its enolic form. The magnetic moment and electronic spectra of all the metal complexes leads to the distorted octahedral symmetry around the metal ion. The ligand as well as its metal complexes has been screened for antimicrobial activity and antifungal activities. It is observed that the antimicrobial and antifungal activities get enhanced in complexes in respect to the free ligand.

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Ati, Rafika El, Haytham Bouammali, Mohamed El Kodadi, El Bekkay Yousfi, Rachid Touzani, and Belkheir Hammouti. "Study of the Catecholase Activity of new catalysts Based on Copper (II) and Heterocyclic Ligands." Indonesian Journal of Science and Technology 7, no. 1 (December 16, 2021): 1–18. http://dx.doi.org/10.17509/ijost.v7i1.41605.

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In this work, we are interested in finding new catalysts for catecholase, whose principle is based on the oxidation reaction of catechol to o-quinone. We approached the synthesis of the threes tripod ligands based on pyrazole in a condensation reaction and its characterization by IR, 13C NMR, 1H NMR spectroscopy, then we evaluated the catalytic properties of certain complexes formed in situ to catalyze the oxidation reaction of catechols to o-quinones. The aim is to find the right models to reproduce the catalytic activity of the enzyme (catecholase), we used complexes formed in situ by pyrazole derivatives with Copper salts. Among these complexes, the complex L4/Cu(CH3COO)2 showed good catalytic activity of the combination (1ligand/2metal) in MeOH for this reaction, with a speed Vmax equal to 69.38 μmol.L-1.min-1 and a low value of Km equal to 0.019 mol.L-1. We have demonstrated that the nature of concentration, ligand, solvent, and copper salts, influenced strongly the catecholase activity.

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J. Prathyusha and C. Asha Deepti. "SYNTHESIS, ANTIMICROBIAL, AND ANTITUBERCULAR ACTIVITIES OF NOVEL N-PYRAZOLYLBENZAMIDE DERIVATIVES." RASAYAN Journal of Chemistry 15, no. 04 (2022): 2407–16. http://dx.doi.org/10.31788/rjc.2022.1547092.

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The current study investigated the antimicrobial and antitubercular activities of novel N-Pyrazolyl Benzamide derivatives. The study includes the synthesis, characterization, and ligand-based molecular docking of the designed molecules. Synthesis of N-Pyrazolyl Benzamide derivatives involves a two-step process in which 5-amino pyrazole (3) intermediate is produced by the condensation reaction of aryl hydrazine (1) and β-keto nitrile (2) in acidic conditions. The final N-Pyrazolyl Benzamide derivatives (5a-n) were synthesized by the reaction involving amide coupling between 5-amino pyrazole (3) and various substituted benzoyl halides (4a-n). The compounds (5a-n) were tested for antimicrobial activity against two gram-negative strains (E. coli and S. Typhi), two gram-positive strains (S. aureus and B. subtilis) and M. tuberculosis MTB H37Rv (ATCC 27294) strains were used for evaluating antitubercular activity. Molecular docking studies of designed derivatives were performed with the Schrodinger glide package against mycobacterial pantothenate synthetase (PDB ID: 4MQ6). All the tested compounds displayed moderate to good antimicrobial and antitubercular activity against the selected strains of bacteria. All the docked molecules were found occupying the active site and established a minimum of two hydrogen bond interactions in molecular docking studies

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18

Youssef, Heba, Jonathan Becker, Clemens Pietzonka, Ilya V. Taydakov, Florian Kraus, and Klaus Müller-Buschbaum. "Divalent Europium, NIR and Variable Emission of Trivalent Tm, Ho, Pr, Er, Nd, and Ce in 3D Frameworks and 2D Networks of Ln–Pyridylpyrazolates." Chemistry 5, no. 2 (April 28, 2023): 1006–27. http://dx.doi.org/10.3390/chemistry5020069.

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The redox reactions of various lanthanide metals with 3-(4-pyridyl)pyrazole (4-PyPzH) or 3-(3-pyridyl)pyrazole (3-PyPzH) ligands yield the 2D network 2∞[Eu(4-PyPz)2(Py)2] containing divalent europium, the 3D frameworks 3∞[Ln(4-PyPz)3] and 3∞[Ln(3-PyPz)3] for trivalent cerium, praseodymium, neodymium, holmium, erbium, and thulium as well as 3∞[La(4-PyPz)3], and the 2D networks 2∞[Ln(4-PyPz)3(Py)] for trivalent cerium and thulium and 2∞[Ln2(4-PyPz)6]·Py for trivalent ytterbium and lutetium. The 18 lanthanide coordination polymers were synthesized under solvothermal conditions in pyridine (Py), partly acting as a co-ligand for some networks. The compounds exhibit a variety of luminescence properties, including metal-centered 4f–4f/5d–4f emission in the visible and near-infrared spectral range, metal-to-ligand energy transfer, and ligand-centered fluorescence and phosphorescence. The anionic ligands 3-PyPz− and 4-PyPz− serve as suitable antennas for lanthanide-based luminescence in the visible and near-infrared range through effective sensitization followed by emission through intra–4f transitions of the trivalent thulium, holmium, praseodymium, erbium, and neodymium. 2∞[Ce(4-PyPz)3(Py)], 3∞[Ce(4-PyPz)3], and 3∞[Ce(3-PyPz)3] exhibit strong degrees of reduction in the 5d excited states that differ in intensity compared to the ligand-based emission, resulting in a distinct emission ranging from pink to orange. The direct current magnetic studies show magnetic isolation of the lanthanide centers in the crystal lattice of 3∞[Ln(3-PyPz)3], Ln = Dy, Ho, and Er.

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Hopa, C. "Ni(II) and Co(II) acetato complexes of pyrazole-pyridine based ligand: synthesis, structure and thermal decomposition." Журнал структурной химии 64, no. 6 (2023): 111520. http://dx.doi.org/10.26902/jsc_id111520.

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Two novel acetato complexes with NNN type planar bdmpp ligand, [Ni(OAc)(H2O)2(bdmpp)]OAc (1) [Co(OAc)(H2O)2(bdmpp)]OAc (2) (bdmpp: 2,6-bis(3,5-dimethylpyrazolyl)pyridine) were synthesized and characterized by elemental analysis, IR spectroscopy and X-ray single-crystal diffraction analysis. Thermal stabilities of these complexes were studied by thermogravimetric (TG) and differential thermal analyses (DTA). The crystal structures of both complexes were also determined using single-crystal X-ray diffraction. It was found that, complexes 1 and 2 possessed smilar octahedral coordination environment in which, metal ions were coordinated by N donor atoms of bdmpp, two oxygens of aqua ligands and one oxygen atom from terminal bonding acetato ligand.

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20

De, Avik, Sukhen Bala, Sayan Saha, Krishna Sundar Das, Sohel Akhtar, Amit Adhikary, Arijit Ghosh, et al. "Lanthanide clusters of phenanthroline containing a pyridine–pyrazole based ligand: magnetism and cell imaging." Dalton Transactions 50, no. 10 (2021): 3593–609. http://dx.doi.org/10.1039/d0dt04122j.

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In this contribution, we report the synthesis, characterization and luminescence–magnetic properties of Ln-clusters (Ln = Gd³⁺, Eu³⁺ and Tb³⁺) using a new pyridine–pyrazole functionalized ligand fitted with a chromophoric phenanthroline backbone. We have applied the luminescence property of clusters for cancer cell imaging.

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Oulmidi, Afaf, Smaail Radi, Haralampos N. Miras, Nayarassery N. Adarsh, and Yann Garcia. "New Bis-Pyrazole-Bis-Acetate Based Coordination Complexes: Influence of Counter-Anions and Metal Ions on the Supramolecular Structures." Sustainability 13, no. 1 (December 30, 2020): 288. http://dx.doi.org/10.3390/su13010288.

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A new flexible bis-pyrazol-bis-acetate ligand, diethyl 2,2’-(pyridine-2,6-diylbis (5-methyl-1H-pyrazole-3,1-diyl))diacetate (L), has been synthesised, and three coordination complexes, namely, [Zn(L)2](BF4)2 (1), [MnLCl2] (2) and [CdLCl2] (3) have been obtained. All ligands and complexes were characterised by IR, mass spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. Single crystal X-ray diffraction experiment revealed that the primary supramolecular building block of 1 is a hexagonal chair shaped 0D hydrogen bonded synthon (stabilised by C–H∙∙∙O hydrogen bonding and C=O∙∙∙π interactions), which further built into a 2D corrugated sheet-like architecture having a 3-c net honeycomb topology, and finally extended to a 3D hydrogen bonded network structure having a five nodal 1,3,3,3,7-c net, through C–H∙∙∙F interactions. On the other hand, the two crystallographically independent molecules of 2 exhibited two distinct supramolecular structures such as 2D hydrogen bonded sheet structure and 1D zigzag hydrogen bonded chain, sustained by C–H∙O and C–H∙∙∙Cl interactions, which are further self-assembled into a 3,4-c network structure, and 3 showed a 2D hydrogen bonded sheet structure. The supramolecular structural diversity in these complexes is due to the different conformations adopted by the ligands, which are mainly induced by different metal ions with coordination environments controlled by different anions. Hirshfeld surface analysis was explored for the qualitative and quantitative analysis of the supramolecular interactions.

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Elsberg, Josiah G., Nicholas G. Spiropulos, Adam C. Colson, and Eric C. Brown. "Crystal structure of a homoleptic zinc(II) complex based on bis(3,5-diisopropylpyrazol-1-yl)acetate." Acta Crystallographica Section E Crystallographic Communications 74, no. 9 (August 16, 2018): 1259–62. http://dx.doi.org/10.1107/s2056989018011246.

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Deprotonation of the methylene group in bis(3,5-diisopropylpyrazol-1-yl)methane with nBuLi and reaction with carbon dioxide yields lithium bis(3,5-diisopropylpyrazol-1-yl)acetate (1). Treatment of 1 with ZnCl2 results in the compound bis[bis(3,5-diisopropylpyrazol-1-yl)acetato]zinc(II), [Zn(C20H31N4O2)2] (2), whose structure has monoclinic (P21/c) symmetry. The ZnII ion resides on an inversion center and is coordinated by two bis(3,5-diisopropylpyrazol-1-yl)acetate (bdippza) ligands. Each ligand facially coordinates the zinc center via κ3 N,N′,O coordination modes to form a distorted octahedral complex with four pyrazole N atoms in the basal plane and two carboxylate O atoms in the axial sites.

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Hirschhausen, Tanja, Lorena Fritsch, Franziska Lux, Jakob Steube, Roland Schoch, Adam Neuba, Hans Egold, and Matthias Bauer. "Iron(III) Complexes with N-Phenylpyrazole-Based Ligands." Inorganics 11, no. 7 (June 29, 2023): 282. http://dx.doi.org/10.3390/inorganics11070282.

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The use of iron as a replacement for noble metals in photochemical and photophysical applications is challenging due to the typically fast deactivation of short-lived catalytically active states. Recent success of a cyclometalated iron(III) complex utilizing a bis-tridentate ligand motif inspired the use of phenyl-1H-pyrazole as a bidentate ligand. Five complexes using the tris(1-phenylpyrazolato-N,C2)iron(III) complex scaffold are presented. In addition to the parent complex, four derivatives with functionalization in the meta-position of the phenyl ring are thoroughly investigated by single crystal diffractometry, UV-Vis-spectroscopy, and cyclic voltammetry. Advanced X-ray spectroscopy in the form of X-ray absorption and emission spectroscopy allows unique insights into the electronic structure as well as DFT calculations. The ligand design leads to overlapping MLCT and LMCT absorption bands, and emissive behavior is suppressed by low-lying MC states.

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Soliman, Saied M., Raghdaa A. Massoud, Hessa H. Al-Rasheed, and Ayman El-Faham. "Syntheses and Structural Investigations of Penta-Coordinated Co(II) Complexes with Bis-Pyrazolo-S-Triazine Pincer Ligands, and Evaluation of Their Antimicrobial and Antioxidant Activities." Molecules 26, no. 12 (June 14, 2021): 3633. http://dx.doi.org/10.3390/molecules26123633.

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Two penta-coordinated [Co(MorphBPT)Cl2]; 1 and [Co(PipBPT)Cl2]; 2 complexes with the bis-pyrazolyl-s-triazine pincer ligands MorphBPT and PipBPT were synthesized and characterized. Both MorphBPT and PipBPT act as NNN-tridentate pincer chelates coordinating the Co(II) center with one short Co-N(s-triazine) and two longer Co-N(pyrazole) bonds. The coordination number of Co(II) is five in both complexes, and the geometry around Co(II) ion is a distorted square pyramidal in 1, while 2 shows more distortion. In both complexes, the packing is dominated by Cl…H, C-H…π, and Cl…C (anion-π stacking) interactions in addition to O…H interactions, which are found only in 1. The UV-Vis spectral band at 564 nm was assigned to metal–ligand charge transfer transitions based on TD-DFT calculations. Complexes 1 and 2 showed higher antimicrobial activity compared to the respective free ligand MorphBPT and PipBPT, which were not active. MIC values indicated that 2 had better activity against S. aureus, B. subtilis, and P. vulgaris than 1. DPPH free radical scavenging assay revealed that all the studied compounds showed weak to moderate antioxidant activity where the nature of the substituent at the s-triazine core has a significant impact on the antioxidant activity.

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Prathyusha, J., and C. Asha Deepti. "Synthesis, Characterization and Evaluation of Anticancer Activity of New Pyrazole-5-carboxamide Derivatives." Asian Journal of Chemistry 35, no. 8 (2023): 2007–14. http://dx.doi.org/10.14233/ajchem.2023.28078.

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In recent years, pyrazole derivatives have emerged as a potentially game-changing new family of cancer chemotherapeutic drugs. Thus, present work used six distinct cancer cell lines to test the new pyrazole-5-carboxamide derivatives for the anticancer activity. Present study includes synthesis, characterization and the ligand-based molecular docking of the compounds. The process begins with ethyl 2,4-dioxopentanoate and methylhydrazine, which was cyclized to form ethyl 1,3-dimethyl-1H-pyrazole- 5-carboxylate (2), which is then transformed to 1,3-dimethyl-1H-pyrazole-5-carbonyl chloride (3) through PCl3/I2. All the pyrazole-4-carboxamides (4a-n) were obtained by the acidic condensation of intermediate 3 with various substituted aryl amines (a-n). The antitumor activity against six cancer cell lines and one regular human cell line was measured using the MTT test. Two target proteins, human c-Met kinase and JAK1, were used in docking studies of the proposed compounds. When compared against the standard drug doxorubicin, most of the synthesized compounds (4a-n) showed the promising cytotoxicity profiles.

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Videira, Margarida, Francisco Silva, António Paulo, Isabel C. Santos, and Isabel Santos. "Synthesis and structural studies of mixed-ligand rhenium(V) complexes anchored by tridentate pyrazole-based ligands." Inorganica Chimica Acta 362, no. 8 (June 2009): 2807–13. http://dx.doi.org/10.1016/j.ica.2008.12.032.

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Murahari, Manikanta, Vivek Mahajan, Sreenivasulu Neeladri, Maushmi S. Kumar, and Y. C. Mayur. "Ligand based design and synthesis of pyrazole based derivatives as selective COX-2 inhibitors." Bioorganic Chemistry 86 (May 2019): 583–97. http://dx.doi.org/10.1016/j.bioorg.2019.02.031.

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Burrows, Andrew D., Siobhan Chan, William J. Gee, Mary F. Mahon, Christopher Richardson, Viorica M. Sebestyen, Domenyk Turski, and Mark R. Warren. "The impact of N,N′-ditopic ligand length and geometry on the structures of zinc-based mixed-linker metal–organic frameworks." CrystEngComm 19, no. 37 (2017): 5549–57. http://dx.doi.org/10.1039/c7ce01447c.

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Comba, Peter, Michael Morgen, and Hubert Wadepohl. "First row transition metal complexes of a hexadentate pyrazole-based bispidine ligand." Polyhedron 52 (March 2013): 1239–45. http://dx.doi.org/10.1016/j.poly.2012.06.035.

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Cubanski, John R., Scott A. Cameron, James D. Crowley, and Allan G. Blackman. "Low symmetry pyrazole-based tripodal tetraamineligands: metal complexes and ligand decomposition reactions." Dalton Trans. 42, no. 6 (2013): 2174–85. http://dx.doi.org/10.1039/c2dt32200e.

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Refaat, Heba M., Atallh A. M. Alotaibi, Necmi Dege, Ayman El-Faham, and Saied M. Soliman. "Synthesis, Structure and Biological Evaluations of Zn(II) Pincer Complexes Based on S-Triazine Type Chelator." Molecules 27, no. 11 (June 5, 2022): 3625. http://dx.doi.org/10.3390/molecules27113625.

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2,4-bis (3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (BPMT) pincer ligand was used to synthesize the new [Zn(BPMT)(NCS)2] (1) and [Zn(BPMT)(Br)2] (2) complexes by a reaction with Zn(NO3)2.6H2O in the presence of either KSCN or KBr, respectively. The structure of complex 1 has been exclusively confirmed using single crystal X-ray diffraction. In this neutral heteroleptic complex, the BPMT is a pincer chelate coordinating the Zn(II) ion via three interactions with the two pyrazole moieties and the s-triazine core. Hence, BPMT is a tridentate NNN-chelate. The coordination environment of Zn(II) is completed by two strong interactions with two terminal SCN− ions via the N-atom. Hence, the Zn(II) is penta-coordinated with a distorted square pyramidal coordination geometry. Hirshfeld analysis indicated the predominance of H…H, H…C and N…H intermolecular interactions. Additionally, the S…H, S…C and S…N contacts are the most significant. The free ligand has no or weak antimicrobial, antioxidant and anticancer activities while the studied Zn(II) complexes showed interesting biological activity. Complex 1 has excellent antibacterial activity against B. subtilis (2.4 μg/mL) and P. vulgaris (4.8 μg/mL) compared to Gentamycin (4.8 μg/mL). Additionally, complex 1 (78.09 ± 4.23 µg/mL) has better antioxidant activity than 2 (365.60 ± 20.89 µg/mL). In addition, complex 1 (43.86 ± 3.12 µg/mL) and 2 (30.23 ± 1.26 µg/mL) have 8 and 12 times the anticancer activity of the free BPMT ligand (372.79 ± 13.64 µg/mL).

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Bhattacharya, Sudeshna, Sukhen Bala, and Raju Mondal. "Ln-MOFs using a compartmental ligand with a unique combination of hard–soft terminals and their magnetic, gas adsorption and luminescence properties." CrystEngComm 21, no. 37 (2019): 5665–72. http://dx.doi.org/10.1039/c9ce01026b.

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Xia, Qinghong, Yanqiu Ren, Mei-Ling Cheng, Xiuxiu Liu, Sheng Chen, Changwei Zhai, and Qi Liu. "Ligand concentration-dependent supramolecular complexes with uncoordinated carbonyl groups based on a new pyrazole carboxylic acid ligand." Journal of Coordination Chemistry 68, no. 10 (March 24, 2015): 1688–704. http://dx.doi.org/10.1080/00958972.2015.1020305.

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34

Pavlova, Anna S., Daniil A. Buslaev, Nataliya E. Borisova, Victor V. Temnov, Alexey A. Nazarov, and Tatyana A. Podrugina. "Cis-(3-benzyloxy-1,1-cyclobutanedicarboxylato κ2O,O′)bis(1-methyl-1H-pyrazole)platinum(II)." Molbank 2023, no. 1 (January 23, 2023): M1564. http://dx.doi.org/10.3390/m1564.

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A huge variety of types of cancer makes it necessary to search for new effective drugs with a defined molecular target. Modification of substituents in ligands based on 3-hydroxy-1,1-cyclobutanedicarboxylic acid are one of the effective directions to design a better version of carboplatin. In the present study, we combined in one molecule a derivative of 3-hydroxycyclobutane-1,1-dicarboxylic acid and N-methylpyrazole as a carrier ligand. The antiproliferative of the novel complex Pt(II) was established for cell lines HCT116, MCF7, A549, and WI38 by means of a standard MTT colorimetric assay.

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35

Luconi, Lapo, Umit B. Demirci, Maurizio Peruzzini, Giuliano Giambastiani, and Andrea Rossin. "Ammonia borane and hydrazine bis(borane) dehydrogenation mediated by an unsymmetrical (PNN) ruthenium pincer hydride: metal–ligand cooperation for hydrogen production." Sustainable Energy & Fuels 3, no. 10 (2019): 2583–96. http://dx.doi.org/10.1039/c9se00241c.

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The pyrazole-based Ru^II unsymmetrical pincer hydride (t^BuPNN*)RuH(CO) has been exploited as ammonia borane and hydrazine bis(borane) dehydrogenation catalyst in THF solution at ambient temperature.

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36

Dias, Isac M., Henrique C. S. Junior, Sabrina C. Costa, Cristiane M. Cardoso, Antonio G. B. Cruz, Claudio E. R. Santos, Dalber R. S. Candela, et al. "Mononuclear coordination compounds containing a pyrazole-based ligand: Syntheses, magnetism and acetylcholinesterase inhibition assays." Journal of Molecular Structure 1205 (April 2020): 127564. http://dx.doi.org/10.1016/j.molstruc.2019.127564.

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37

Tian, Ai-xiang, Ya-li Ning, Jun Ying, Xue Hou, Tian-jiao Li, and Xiu-li Wang. "Three multi-nuclear clusters and one infinite chain induced by a pendant 4-butyl-1H-pyrazole ligand for modification of Keggin anions." Dalton Transactions 44, no. 1 (2015): 386–94. http://dx.doi.org/10.1039/c4dt02821j.

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By utilizing a pendant 4-butyl-1H-pyrazole, four POM-based multi-nuclear clusters or infinite chain subunits are formed: tetra-, tri- and penta-nuclear clusters in 1, 3 and 4 and an infinite chain in 2.

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Ozers, Mary Szatkowski, Kerry M. Ervin, Corrine L. Steffen, Jennifer A. Fronczak, Connie S. Lebakken, Kimberly A. Carnahan, Robert G. Lowery, and Thomas J. Burke. "Analysis of Ligand-Dependent Recruitment of Coactivator Peptides to Estrogen Receptor Using Fluorescence Polarization." Molecular Endocrinology 19, no. 1 (January 1, 2005): 25–34. http://dx.doi.org/10.1210/me.2004-0256.

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Abstract Ligand-dependent recruitment of coactivators to estrogen receptor (ER) plays an important role in transcriptional activation of target genes. Agonist-bound ER has been shown to adopt a favorable conformation for interaction with the LXXLL motifs of the coactivator proteins. To further examine the affinity and ligand dependence of the ER-coactivator interaction, several fluorescently tagged short peptides bearing an LXXLL motif (LXXLL peptide) from either natural coactivator sequences or random phage display sequences were used with purified ERα or ERβ in an in vitro high-throughput fluorescence polarization assay. In the presence of saturating amounts of ligand, several LXXLL peptides bound to ERα and ERβ with affinity ranging from 20–500 nm. The random phage display LXXLL peptides exhibited a higher affinity for ER than the natural single-LXXLL coactivator sequences tested. These studies indicated that ER agonists, such as 17β-estradiol or estrone, promoted the interaction of ER with the coactivator peptides, whereas antagonists such as 4-hydroxytamoxifen or ICI-182,780 did not. Different LXXLL peptides demonstrated different affinities for ER depending on which ligand was bound to the receptor, suggesting that the peptides were recognizing different receptor conformations. Using the information obtained from direct measurement of the affinity of the ER-LXXLL peptide interaction, the dose dependency (EC50) of various ligands to either promote or disrupt this interaction was also determined. Interaction of ER with the LXXLL peptide was observed with ligands such as 17β-estradiol, estriol, estrone, and genistein but not with ICI-182,780, 4-hydroxytamoxifen, clomiphene, or tamoxifen, resulting in distinct EC50 values for each ligand and correlating well with the ligand biological function as an agonist or antagonist. Ligand-dependent recruitment of the LXXLL peptide to ERβ was observed in the presence of the ERβ-selective agonist diarylpropionitrile, but not the ERα-selective ligand propyl pyrazole triol. This assay could be used to classify unknown ligands as agonists, antagonists, or partial modulators, based on either the receptor-coactivator peptide affinities or the dose dependency of this interaction in comparison with known compounds.

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39

Al-Hazmy, Sadeq M., Mohamed Oussama Zouaghi, Nasser Amri, Youssef Arfaoui, Ibrahim A. Alhagri, and Naceur Hamdi. "DFT Study of Regio- and Stereoselective 13DC Reaction between Diazopropane and Substituted Chalcone Derivatives: Molecular Docking of Novel Pyrazole Derivatives as Anti-Alzheimer’s Agents." Molecules 28, no. 4 (February 16, 2023): 1899. http://dx.doi.org/10.3390/molecules28041899.

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In the present work, a combination of experimental and density functional theory(DFT) investigation of the (3+2) cycloaddition reactions of diazopropane with chalcone derivatives was reported. All calculations were performed using several DFT approaches (B3LYP, M06, M06-2X) and 6-311+G(d, p) basis set. Based on the NMR, MS analyses and IRC calculations, the pyrazole derivatives are the kinetic adducts over the oxadiazoles. The use of two equivalents of diazopropane leads to thermodynamical products. A molecular docking analysis was performed to investigate the efficiency of the obtained products against selected drug targets in anti-Alzheimer ligand-receptor interactions. We revealed that the ligands selected were bound mainly to the catalytic (CAS) and peripheral (PAS) anionic sites of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors, respectively. The selected ligands 1, 3, 4 and P14 may act as the best inhibitors against Alzheimer’s disease (AD).

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Nikovskiy, Igor A., Pavel V. Dorovatovskii, Valentin V. Novikov, and Yulia V. Nelyubina. "Bis(2,6-pyrazolyl)pyridines as a New Scaffold for Coordination Polymers." Molecules 28, no. 11 (May 23, 2023): 4275. http://dx.doi.org/10.3390/molecules28114275.

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Two coordination polymers, Fe(LOBF3)(CH3COO)(CH3CN)2]n•nCH3CN and [Fe(LO−)2AgNO3BF4•CH3OH]n•1.75nCH3OH•nH2O (LO− = 3,3′-(4-(4-cyanophenyl)pyridine-2,6-diyl)bis(1-(2,6-dichlorophenyl)-1H-pyrazol-5-olate)), were obtained via a PCET-assisted process that uses the hydroxy-pyrazolyl moiety of the ligand and the iron(II) ion as sources of proton and electron, respectively. Our attempts to produce heterometallic compounds under mild conditions of reactant diffusion resulted in the first coordination polymer of 2,6-bis(pyrazol-3-yl)pyridines to retain the core N3(L)MN3(L). Under harsh solvothermal conditions, a hydrogen atom transfer to the tetrafluoroborate anion caused the transformation of the hydroxyl groups into OBF3 in the third coordination polymer of 2,6-bis(pyrazol-3-yl)pyridines. This PCET-assisted approach may be applicable to produce coordination polymers and metal–organic frameworks with the SCO-active core N3(L)MN3(L) formed by pyrazolone- and other hydroxy-pyridine-based ligands.

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41

Syahputri, Yulian, Ani Iryani, Linda Jati Kusumawardani, and Shinta Safitri. "Metal Ion Complex Compound Fe(III) with Pyrazoline Derivative Ligand as Cd(II) and Zn(II) Heavy Metal Ion Sensor Based on Fluorescence." JKPK (Jurnal Kimia dan Pendidikan Kimia) 7, no. 2 (August 31, 2022): 234. http://dx.doi.org/10.20961/jkpk.v7i2.55419.

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<p>The purpose of this research is to synthesize the complex compound of ion Fe<sup>3+</sup> with para-di-2-(1-phenyl-3-pyridyl-4,5-dihydro-1H-pyrazole-5-yl)benzene ligand and its potentials as the sensor of Cd<sup>2+</sup> and Zn<sup>2+</sup> heavy metal ions based on fluorescence. Complex compounds are characterized with a Fourier-Transform Infrared (FTIR) Spectrophotometer, Ultraviolet-Visible (UV-Vis) Spectrophotometer and Spectrofluorometer. Then, a complex compound fluorosensor study is conducted by adding Cd<sup>2+</sup> and Zn<sup>2+</sup> heavy metal ions using a UV-Vis Spectrophotometer and Spectrofluorometer. The results show that the synthesis of the complex compound formed by reacting Fe metal and pyrazoline derived ligands generates brown precipitate with a yield of 51.25% and a range of melting points of 252.2-253.2 . The result of characterization with FTIR (cm<sup>-1</sup>) generates 3380.20 (tertiary amine), 2922.31-2852.42 (C-H pyridine), 2360.38 (C=C aromatic), 1595.93-1451.88 (C=N), 1232.25-982.66 (C-N pyrazoline), 751.61-690.29 (C-H aromatic) and 366.54-339.44 (Fe-N). The Uv-Vis spectrophotometer study with a concentration of 5x10<sup>-5 </sup>M showed two absorption peaks at 246 nm, 354 nm, and 440 nm. The resulting fluorescence intensity of 813.1 a.u. at the wavelenght of 500 nm. The study of complex compound fluorescence shows that the addition of Cd<sup>2+</sup> heavy metal ion can be made as fluorosensor with turn-on (enhancement) type, while the complex compound in the addition of Zn<sup>2+</sup> heavy metal ion can be made as fluorosensor with turn off-on (quenching-enhancement) type.</p>

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42

Mukherjee, Anuradha, and Amitabha Sarkar. "Pyrazole-based P,N-ligand for palladium catalyst: applications in Suzuki coupling and amination reactions." Arkivoc 2003, no. 9 (February 28, 2004): 87–95. http://dx.doi.org/10.3998/ark.5550190.0004.911.

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43

Musa, Taghreed M., Zaizafoone N. Nasif, and Mahmoud Najim Abid Al-jibouri. "Synthesis, Structural and Biological Studies of Some Metal Complexes derived from Tridentate Pyrazole-based Ligand." Research Journal of Pharmacy and Technology 13, no. 4 (2020): 1735. http://dx.doi.org/10.5958/0974-360x.2020.00313.3.

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44

Xu, Hongliang, Xinchen Li, Xujing Zhang, Long Peng, Dengfeng Zou, and Jie Yang. "Synthesis and anticancer property of an octanuclear Mn(III) compound based on pyrazole bifunctional ligand." Journal of Coordination Chemistry 73, no. 12 (June 17, 2020): 1806–16. http://dx.doi.org/10.1080/00958972.2020.1793137.

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45

Yamagishi, Hiroaki, Hiroyuki Konuma, and Shigeki Kuwata. "Stereoselective synthesis of chlorido–phosphine ruthenium complexes bearing a pyrazole-based protic tripodal amine ligand." Polyhedron 125 (March 2017): 173–78. http://dx.doi.org/10.1016/j.poly.2016.11.037.

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46

Kang, Youn K., Jong Hwa Jeong, Na Young Lee, Young Tak Lee, and Hyosun Lee. "Synthesis, characterization, and catalytic application of a zinc(II) complex bearing a pyrazole-based ligand." Polyhedron 29, no. 12 (August 2010): 2404–8. http://dx.doi.org/10.1016/j.poly.2010.05.009.

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Kumar, Sushil, Aayushi Arora, Arun Kumar, and Kapil Tomar. "An unsymmetrical tritopic pyrazole carboxylate ligand based porous Cd(II) MOF sensor for acetone molecule." Inorganic Chemistry Communications 96 (October 2018): 16–19. http://dx.doi.org/10.1016/j.inoche.2018.07.042.

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48

Singh, Vishwa Deepak, Rajendra Prasad Paitandi, Yogesh Kumar, and Daya Shankar Pandey. "An AIE active BODIPY based fluorescent probe for selective sensing of Hg2+ via dual mechanism PET and CHEF." Journal of Porphyrins and Phthalocyanines 25, no. 05n06 (April 12, 2021): 493–99. http://dx.doi.org/10.1142/s1088424621500383.

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A pyrazole appended BODIPY ligand (L) is synthesized and thoroughly characterized by various spectroscopic studies (1H, [Formula: see text]C, [Formula: see text]B, [Formula: see text]F, ESI–MS, UV-vis and fluorescence). The ligand (L) displays aggregation induced emission (AIE) in solution (a mixture of CH3OH and water) and solid state. The vital role of the restriction of intramolecular rotation (RIR) in AIE is supported by viscosity experiments and fluorescence lifetime studies. Photophysical behaviour and aggregate morphology is investigated by UV-vis, emission and scanning electron microscopy (SEM). Multiple strong intermolecular hydrogen bonds (C–H[Formula: see text]N and C–H[Formula: see text]F) play a significant role in the AIE response. In addition, L shows strong sensitivity toward Hg[Formula: see text]ion via chelation induced enhanced fluorescence (CHEF) mechanism. Job’s plot analysis suggested a 1:1 binding stoichiometry between L and Hg[Formula: see text], which has been further supported by electrospray ionization mass spectrometry and density functional theory.

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El-behairy, Mohammed Farrag, and Hanan Naeim Hafez Attia. "DESIGN, SYNTHESIS AND ANTICONVULSANT PROFILE OF 5-(BENZO [D][1,3]DIOXOL-5-YL)-3-TERT-BUTYL-4, 5-DIHYDROPYRAZOLE DERIVATIVES." International Journal of Pharmacy and Pharmaceutical Sciences 9, no. 6 (June 1, 2017): 180. http://dx.doi.org/10.22159/ijpps.2017v9i6.17520.

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Objective: Utilisation of the ligand-based design and molecular hybridization to design promising candidates with prospective efficacy and safety. Synthesis of the designed candidates using different synthetic methods. Biological evaluation of the newly synthesised candidates as anticonvulsant agents.Methods: Three novel series of 5-(benzo[d][1,3]dioxol-5-yl)-3-tert-butyl-4,5-dihydropyrazoles have been designed via ligand-based drug discovery and molecular hybridization. Proper synthetic routes have been followed in the preparation of compounds (2-23) which have been characterised by different spectral techniques. Antiepileptic potential was assessed by biological evaluation using ‘classical’ animal models of epilepsy, in addition to rotarod test for toxicity.Results: 4-Nitrophenyl derivatives (5, 13, and19) displayed the highest potency. Compound 5was the most active substituent in series A (N'-aroyl-3-tert-butyl-4,5-dihydro-1H-pyrazole-1-carbohydrazide). It was 2.7 and 1.3 times more active than reference drug Stiripentol (I) and lead compound III, respectively. Compound13 was the best candidate in series B (N'-arylidene-3-tert-butyl-4,5-dihydro-1H-pyrazole-1-carbohydrazide). It was 3.3, 1.5, and 1.2 times more potent than Stiripentol, lead compound III and new compound 5, respectively. Two members (19 and 21) of series C (1,3,4-oxadiazole derivatives) achieved 100 % protection at lower doses than I and III, being 2.6 and 2.4 times more active than Stiripentol. In scPTZ screen, the most active congeners (5, 13, 19) exhibited ED50 values of 45, 48, and 81 mg/kg, respectively, which are highly superior as compared to that of reference drug Stiripentol(I) and lead compound III (ED50 115 and 110 mg/kg, respectively).Conclusion: Ligand-based design together with molecular hybridization in drug design succeeded to produce potent and wide spectrum candidates.

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Toda, Tatsuro, and Shigeki Kuwata. "Synthesis, Structures, and Reactivities of Iron Complexes Bearing an Isoindoline‐Based, Polyprotic Pincer‐Type Pyrazole Ligand." Zeitschrift für anorganische und allgemeine Chemie 647, no. 14 (May 17, 2021): 1471–77. http://dx.doi.org/10.1002/zaac.202100103.

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