Design and synthesis of dichromeno[2,3-b;3′,2′-e]pyridine-12,14-dione to evaluate its optical properties

2017 ◽  
Vol 41 (10) ◽  
pp. 3887-3893 ◽  
Author(s):  
Pritam Biswas ◽  
Jaydip Ghosh ◽  
Tapas Sarkar ◽  
Debabrata Jana ◽  
Chandrakanta Bandyopadhyay
Keyword(s):  
Cyclic Voltammetry ◽  
Optical Properties ◽  
Thermogravimetric Analysis ◽  
Dft Calculations ◽  
Design And Synthesis ◽  
Mild Conditions ◽  
Cv Measurements

An unambiguous synthesis of dichromeno[2,3-b;3′,2′-e]pyridine-12,14-diones has been developed under mild conditions and their optical properties have been evaluated by studying UV-vis absorption and photoluminescence (PL) spectroscopy, cyclic voltammetry (CV) measurements, DFT calculations and thermogravimetric analysis.

Pt-Pd Nanoalloy for the Unprecedented Activation of Carbon-Fluorine Bond at Low Temperature

2019 ◽  
Author(s):  
Raghu Nath Dhital ◽  
keigo nomura ◽  
Yoshinori Sato ◽  
Setsiri Haesuwannakij ◽  
Masahiro Ehara ◽  
...  
Keyword(s):  
Activation Energy ◽  
Low Temperature ◽  
Dft Calculations ◽  
Bond Activation ◽  
Mild Conditions ◽  
Selective Transformation ◽  
Rate Determining Step ◽  
Highly Active ◽  
Harsh Conditions ◽  
Reaction Profile

Carbon-Fluorine (C-F) bonds are considered the most inert organic functionality and their selective transformation under mild conditions remains challenging. Herein, we report a highly active Pt-Pd nanoalloy as a robust catalyst for the transformation of C-F bonds into C-H bonds at low temperature, a reaction that often required harsh conditions. The alloying of Pt with Pd is crucial to activate C-F bond. The reaction profile kinetics revealed that the major source of hydrogen in the defluorinated product is the alcoholic proton of 2-propanol, and the rate-determining step is the reduction of the metal upon transfer of the <i>beta</i>-H from 2-propanol. DFT calculations elucidated that the key step is the selective oxidative addition of the O-H bond of 2-propanol to a Pd center prior to C-F bond activation at a Pt site, which crucially reduces the activation energy of the C-F bond. Therefore, both Pt and Pd work independently but synergistically to promote the overall reaction

scholarly journals Suitability of the Cyclic Voltammetry Measurements and DPPH• Spectrophotometric Assay to Determine the Antioxidant Capacity of Food-Grade Oenological Tannins

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2925 ◽  
Author(s):  
Arianna Ricci ◽  
Giuseppina Paola Parpinello ◽  
Nemanja Teslić ◽  
Paul Andrew Kilmartin ◽  
Andrea Versari
Keyword(s):  
Cyclic Voltammetry ◽  
Colorimetric Assay ◽  
Radical Scavenging ◽  
Calibration Graph ◽  
Spectrophotometric Assay ◽  
Experimental Conditions ◽  
Fast Analysis ◽  
Cv Measurements ◽  
And Control ◽  
Analytical Approaches

Twenty commercially available oenological tannins (including hydrolysable and condensed) were assessed for their antiradical/reducing activity, comparing two analytical approaches: The 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging spectrophotometric assay and the cyclic voltammetry (CV) electrochemical method. Electrochemical measurements were performed over a −200 mV–500 mV scan range, and integrated anodic currents to 500 mV were used to build a calibration graph with (+)-catechin as a reference standard (linear range: From 0.0078 to 1 mM, R2 = 0.9887). The CV results were compared with the DPPH• assay (expressed as % of radical scavenged in time), showing high correlation due to the similarity of the chemical mechanisms underlying both methods involving polyphenolic compounds as reductants. Improved correlation was observed by increasing the incubation time with DPPH• to 24 h (R2 = 0.925), demonstrating that the spectrophotometric method requires a long-term incubation to complete the scavenging reaction when high-molecular weight tannins are involved; this constraint has been overcome by using instant CV measurements. We concluded that the CV represents a valid alternative to the DPPH• colorimetric assay, taking advantage of fast analysis and control on the experimental conditions and, because of these properties, it can assist the quality control along the supply chain.

A first-principles study on the electronic and optical properties of a type-II C2N/g-ZnO van der Waals heterostructure

2021 ◽  
Vol 23 (6) ◽  
pp. 3963-3973
Author(s):  
Jianxun Song ◽  
Hua Zheng ◽  
Minxia Liu ◽  
Geng Zhang ◽  
Dongxiong Ling ◽  
...  
Keyword(s):  
Optical Properties ◽  
Dft Calculations ◽  
First Principles ◽  
Van Der Waals ◽  
Band Alignment ◽  
Type Ii ◽  
Electronic And Optical Properties ◽  
Direct Bandgap ◽  
Van Der Waals Heterostructure ◽  
Vdw Heterostructure

The structural, electronic and optical properties of a new vdW heterostructure, C2N/g-ZnO, with an intrinsic type-II band alignment and a direct bandgap of 0.89 eV at the Γ point are extensively studied by DFT calculations.

scholarly journals Role of the Anilinium Ion on the Selective Polymerization of Anilinium 2-Acrylamide-2-methyl-1-propanesulfonate

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2349
Author(s):  
Alain Salvador Conejo-Dávila ◽  
Marco Armando Moya-Quevedo ◽  
David Chávez-Flores ◽  
Alejandro Vega-Rios ◽  
Erasto Armando Zaragoza-Contreras
Keyword(s):  
Cyclic Voltammetry ◽  
Optical Properties ◽  
Thermal Properties ◽  
Free Radical ◽  
1H Nmr ◽  
Molecular Interactions ◽  
13C Nmr ◽  
Oxidative Polymerization ◽  
Cyclic Voltammetry Analysis

The development of anilinium 2-acrylamide-2-methyl-1-propanesulfonate (Ani-AMPS) monomer, confirmed by 1H NMR, 13C NMR, and FTIR, is systematically studied. Ani-AMPS contains two polymerizable functional groups, so it was submitted to selective polymerization either by free-radical or oxidative polymerization. Therefore, poly(anilinium 2-acrylamide-2-methyl-1-propanesulfonic) [Poly(Ani-AMPS)] and polyaniline doped with 2-acrylamide-2-methyl-1-propanesulfonic acid [PAni-AMPS] can be obtained. First, the acrylamide polymer, poly(Ani-AMPS), favored the π-stacking of the anilinium group produced by the inter- and intra-molecular interactions and was studied utilizing 1H NMR, 13C NMR, FTIR, and UV-Vis-NIR. Furthermore, poly(Ani-AMPS) fluorescence shows quenching in the presence of Fe2+ and Fe3+ in the emission spectrum at 347 nm. In contrast, the typical behavior of polyaniline is observed in the cyclic voltammetry analysis for PAni-AMPS. The optical properties also show a significant change at pH 4.4. The PAni-AMPS structure was corroborated through FTIR, while the thermal properties and morphology were analyzed utilizing TGA, DSC (except PAni-AMPS), and FESEM.

scholarly journals DFT study of superhalogen and superalkali doped graphitic carbon nitride and its non-linear optical properties

RSC Advances ◽  
2021 ◽  
Vol 11 (14) ◽  
pp. 7779-7789 ◽  
Author(s):  
Asmat Ullah Khan ◽  
Rasheed Ahmad Khera ◽  
Naveed Anjum ◽  
Rao Aqil Shehzad ◽  
Saleem Iqbal ◽  
...  
Keyword(s):  
Optical Properties ◽  
Dft Calculations ◽  
Nonlinear Optical ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Dft Study ◽  
Nlo Properties ◽  
Non Linear ◽  
Linear Optical Properties

DFT calculations are carried out to investigate nonlinear optical (NLO) properties of superhalogen (BCl4) and superalkali (NLi4) doped graphitic carbon nitride (GCN).

scholarly journals Rhodanine-based dyes absorbing in the entire visible spectrum

2017 ◽  
Vol 4 (6) ◽  
pp. 1024-1028 ◽  
Author(s):  
Rafael Sandoval-Torrientes ◽  
Joaquín Calbo ◽  
David García-Fresnadillo ◽  
José Santos ◽  
Enrique Ortí ◽  
...  
Keyword(s):  
Optical Properties ◽  
Dft Calculations ◽  
Electrochemical Characterizations ◽  
Visible Spectrum ◽  
Electronic And Optical Properties ◽  
Entire Visible Spectrum

A series of new broad-absorbing rhodanine-fluorene dyes conjugated with triarylamines are presented. Spectroscopic and electrochemical characterizations, along with theoretical DFT calculations, unveil the electronic and optical properties of the dyes.

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