Combined XRD and DFT studies towards understanding the impact of intramolecular H-bonding on the reductive cyclization process in pyrazole derivatives

Szlachcic, Paweł; Uchacz, Tomasz; Gryl, Marlena; Danel, Andrzej; Wojtasik, Katarzyna; Kolek, Przemysław; Jarosz, Bożena; Stadnicka, Katarzyna

doi:10.1016/j.molstruc.2019.127087

Cited by 21 publications

(8 citation statements)

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“…Good results of the experiment carried out at high temperatures, as well as poor or no results at lower temperatures (Table 1) confirm the assumptions described in the article by Szlachcic et al concerning unfavorable conformations, not very reactive, stabilized by hydrogen bonds of system 1 at room temperature. [12] To change the conformation into reactive and break the stabilizing hydrogen bonds, the reaction must be carried out at high temperature. To confirm the assumption about the relationship of the reaction with temperature, an experiment in sulfolane with the use of triphenylphosphine as a reducing agent was carried out (Table 1, item 3), analogously to the procedure with iron (II) oxalate.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of 1H‐Pyrazolo[3,4‐b]quinoxaline Derivatives by Modification of the Regiospecific Reaction – the Influence of the Microwave Field

et al. 2021

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The microwave-assisted reductive cyclization reaction with the use of triphenylphosphine as a reducing agent in the synthesis of 1H-pyrazolo[3,4-b]quinoxaline derivatives was investigated. Contrary to the conventional method of conducting the reaction, the process in the reactor takes 25 minutes with moderate yields (30-38 %). This procedure was used to obtain three new 1,3-dimethyl-1H-pyrazolo [3,4-b]quinoxaline derivatives with substituents at position 6 of different donor-acceptor character, which were used to determine the basic photophysical properties (UV-Vis absorption spectra, fluorescence emission spectra) and the quantum yields of fluorescence were appointed. The measurement results indicate the possible use of new compounds as materials for OLEDs. The conducted research brings new knowledge in the field of 1H-pyrazolo [3,4b]quinoxaline derivative systems and provides an alternative to conventional synthesis of pyrazoloquinoxalines.

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Section: Resultsmentioning

confidence: 99%

Synthesis of 1H‐Pyrazolo[3,4‐b]quinoxaline Derivatives by Modification of the Regiospecific Reaction – the Influence of the Microwave Field

et al. 2021

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“…These compounds exhibit various biological activities such as antibacterial [ 5 , 6 ] or antifungal [ 7 ]. This makes CNAs often used in many reactions such as Michael addition [ 8 , 9 ] as well as cycloaddition (CA) reactions, to synthesize heterocycles, especially for the preparation of five-membered rings [ 10 ] like pyrazolines [ 11 , 12 ], isoxazolines [ 13 , 14 , 15 , 16 ] or pyrrolidine [ 17 , 18 ], and six-membered rings in the Diels-Alder reaction [ 19 , 20 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

(1E,3E)-1,4-Dinitro-1,3-butadiene—Synthesis, Spectral Characteristics and Computational Study Based on MEDT, ADME and PASS Simulation

Sadowski,

Synkiewicz-Musialska,

Kula

2024

Molecules

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The chemistry of conjugated nitrodienes is becoming increasingly popular. These molecules are successfully applied in cycloaddition to synthesize six-membered rings in Diels-Alder reactions. Nitrodienes can be also applied to obtain bis-compounds in [3+2] cycloaddition. Moreover, the presence of a nitro group in the structure provides a possibility of further modification of the products. The simplest symmetrical representative of conjugated nitrodienes is (1E,3E)-1,4-dinitro-1,3-butadiene. Although the first mentions of the compound date back to the early 1950s, the compound has not yet been examined thoroughly enough. Therefore, in this article, a comprehensive study of (1E,3E)-1,4-dinitro-1,3-butadiene has been described. For this purpose, an experimental study including the synthesis process as well as an evaluation of the spectral characteristics has been conducted. So as to better understand the properties of this compound, a computational study of reactivity indices based on MEDT and also an assessment of pharmacokinetics and biological activity according to ADME and PASS methodologies have been made. On this basis, some future application trends of (1E,3E)-1,4-dinitro-1,3-butadiene have been proposed.

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“…33 The goal is to show how much precision can be consistently attained by applying the same atomistic modeling techniques throughout the experimental investigation. 34 Ab initio pseudopotentials are used to express the potential of an electron−ion using either standard-conserving or ultrasoft formulations. Direct energy reduction produces the proper charge intensity, a method that is consistent with consciousness, and Kohn−Sham wave functions.…”

Section: Introductionmentioning

confidence: 99%

“…Particular techniques for conjugate gradients and density mixing are used. For systems with a small population, a strong DFT electron gives a form that may be employed . The base set size provided by the energy cutoff for plane waves and the Brillouin zone integration accuracy calculated from copolymer and composite k points are the two factors that control measurement convergence.…”

Section: Introductionmentioning

confidence: 99%

Removal of Toxic Basic Fuchsin Dye from Liquids by Antibiotic Azithromycin Using Adsorption, TD-DFT Calculations, Kinetic, and Equilibrium Studies

Mohamed

Hassan

Ahmed

et al. 2023

Ind. Eng. Chem. Res.

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This work aims to study the removal of new fuchsin dye (NFD) using azithromycin (Az) by a spectrophotometric technique at two different wavelengths (547 and 286 nm), which formed the blend [Az+NFD]. Afterward, the [Az]TF, [NFD]TF, and nanoblend [Az+NFD]NB thin films were fabricated using the spin-coating technique. The models of Langmuir and Freundlich isotherms were applied to examine the experimental data of adsorption equilibrium and activation parameters. At 547 and 286 nm, the sorption capacity (q m) was determined to be 0.0095 and 0.01 mg g–1, correspondingly. The kinetic data showed that the reaction was fitted with a first-order reaction and the maximum adsorption capacity of Az at 547 nm was 0.0198 mg g–1 at 313 and 323 K, whereas at 286 nm, it was 0.0071 mg g–1 at 303 K. The thermodynamic parameters (ΔH°, ΔS°, and ΔG°) were calculated, and the experimental results showing negative values of ΔH° at 547 and 286 nm (−33.67 and −11.22 kJ mol–1, respectively) indicate the adsorption of NFD using Az is an exothermic reaction. The negative values of ΔG° at 547 and 286 nm (−19.67 and −13.01 kJ mol–1, respectively) indicate a spontaneous reaction. The calculated time-dependent density functional theory (TD-DFT) spectra matched the measured IR spectra precisely and corroborated the molecular structure of the tested materials. The experimental values and TD-DFT/CASTEP predictions for these properties are in great agreement. The optical (TD-DFT/CASTEP) characteristics of the [Az]Iso, [NFD]Iso, and [Az+NFD]NB gaseous phases are in close agreement with the experimental results. The greatest absorption bands for [Az]TF, [NFD]TF, and [Az+NFD]NB correspond to the π → π* electronic transition at 268, 547, and 625 nm, respectively, and the Gaussian program corresponds well with the experimental analysis for synthetic IR and molecular electrostatic potential. Optical illumination studies suggest that the nanoblend device films investigated may be employed in solar cell applications. The quantity of dye removed by Az decreases with an increase in the contact time and optimum adsorption was achieved in 4 min at 547 nm, whereas it increases with time at 286 nm and an optimum adsorption capacity was achieved in 6 min. The isolated molecule of [Az+NFD]Iso has a band gap of 2.415 eV, as determined by TD-DFT/DMol3. Thin films of thickness 100 ± 3 nm of [Az]TF, [NFD]TF, and [Az+NFD]NB via a spin-coating technique at room temperature were fabricated.

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Combined XRD and DFT studies towards understanding the impact of intramolecular H-bonding on the reductive cyclization process in pyrazole derivatives

Cited by 21 publications

References 74 publications

Synthesis of 1H‐Pyrazolo[3,4‐b]quinoxaline Derivatives by Modification of the Regiospecific Reaction – the Influence of the Microwave Field

Synthesis of 1H‐Pyrazolo[3,4‐b]quinoxaline Derivatives by Modification of the Regiospecific Reaction – the Influence of the Microwave Field

(1E,3E)-1,4-Dinitro-1,3-butadiene—Synthesis, Spectral Characteristics and Computational Study Based on MEDT, ADME and PASS Simulation

Removal of Toxic Basic Fuchsin Dye from Liquids by Antibiotic Azithromycin Using Adsorption, TD-DFT Calculations, Kinetic, and Equilibrium Studies

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