Conformational Dynamics in Excited States and Photophysical Properties of Meso-Substituted Nitro Derivatives of Octaethylporphyrin and Their Zn Complexes

2021 ◽  
Author(s):  
N. V. Ivashin
Keyword(s):  
Excited States ◽  
Photophysical Properties ◽  
Conformational Dynamics ◽  
Nitro Derivatives ◽  
Derivatives Of

Solvent Dependence of Structural Dynamics and Spin-flip Processes in 3,4,5-tri(9H-carbazole-9-yl)benzonitrile (ortho-3CzBN)

2020 ◽  
Author(s):  
Masaki Saigo ◽  
Kiyoshi Miyata ◽  
Hajime Nakanotani ◽  
Chihaya Adachi ◽  
Ken Onda
Keyword(s):  
Dft Calculations ◽  
Excited States ◽  
Structural Changes ◽  
Photophysical Properties ◽  
Delayed Fluorescence ◽  
Time Resolved ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Solvent Dependence ◽  
Acetonitrile Solutions

We have investigated the solvent-dependence of structural changes along with intersystem crossing of a thermally activated delayed fluorescence (TADF) molecule, 3,4,5-tri(9H-carbazole-9-yl)benzonitrile (o-3CzBN), in toluene, tetrahydrofuran, and acetonitrile solutions using time-resolved infrared (TR-IR) spectroscopy and DFT calculations. We found that the geometries of the S1 and T1 states are very similar in all solvents though the photophysical properties mostly depend on the solvent. In addition, the time-dependent DFT calculations based on these geometries suggested that the thermally activated delayed fluorescence process of o-3CzBN is governed more by the higher-lying excited states than by the structural changes in the excited states.<br>

QSAR Analysis of Selected Antimicrobial Structures Belonging to Nitro-derivatives of Heterocyclic Compounds

2020 ◽  
Vol 17 (2) ◽  
pp. 214-225 ◽  
Author(s):  
Piotr Kawczak ◽  
Leszek Bober ◽  
Tomasz Bączek
Keyword(s):  
Antimicrobial Activity ◽  
Heterocyclic Compounds ◽  
Molecular Descriptors ◽  
Microbiological Activity ◽  
Activity Data ◽  
Qsar Analysis ◽  
Qsar Models ◽  
Nitro Derivatives ◽  
Semi Empirical ◽  
Derivatives Of

Background: Nitro-derivatives of heterocyclic compounds were used as active agents against pathogenic microorganisms. A set of 4- and 5-nitroimidazole derivatives exhibiting antimicrobial activity was analyzed with the use of Quantitative Structure-Activity Relationships (QSAR) method. The study included compounds used both in documented treatment and those described as experimental. Objective: The purpose of this study was to demonstrate the common and differentiating characteristics of the above-mentioned chemical compounds alike physicochemically as well as pharmacologically based on the quantum chemical calculations and microbiological activity data. Methods: During the study PCA and MLR analysis were performed, as the types of proposed chemometric approach. The semi-empirical and ab initio level of in silico molecular modeling was performed for calculations of molecular descriptors. Results: QSAR models were proposed based on chosen descriptors. The relationship between the nitro-derivatives structure and microbiological activity data was able to class and describe the antimicrobial activity with the use of statistically significant molecular descriptors. Conclusion: The applied chemometric approaches revealed the influential features of the tested structures responsible for the antimicrobial activity of studied nitro-derivatives.

Electrochemical reduction of para-substituted 2-acyl-5-phenylfuranes in dimethylformamide

1981 ◽  
Vol 46 (2) ◽  
pp. 498-502 ◽  
Author(s):  
Jozef Černák ◽  
František Tomanovič ◽  
Andrej Staško ◽  
Anna Fedosyevna Oleinikova ◽  
Jaroslav Kováč
Keyword(s):  
Electrochemical Reduction ◽  
Unpaired Electron ◽  
Anion Radical ◽  
Electron Wave ◽  
Epr Method ◽  
Electron Center ◽  
Nitrogen Nucleus ◽  
Nitro Derivatives ◽  
Stable Anion ◽  
Derivatives Of

para Substituted chloro, bromo, and nitro derivatives of 2-acyl-5-phenylfurane are reduced polarographically in a one-electron wave to the corresponding anion radicals, which were studied by the EPR method. The reduction of nitro derivatives, studied by the Kalousek switch, is reversible and leads to a stable anion radical with an unpaired electron center on the nitrogen nucleus; the reduction of the halogen derivatives is only partly reversible and leads to unstable ketyl radicals. The bromo derivatives give polarographic maxima typical for concurrent reactions.

scholarly journals Core-Substituted Naphthalene-diimides (cNDI) and Related Derivatives: Versatile Scaffold for Supramolecular Assembly and Functional Materials

2021 ◽  
Author(s):  
Anurag Mukherjee ◽  
Suhrit Ghosh
Keyword(s):  
Photophysical Properties ◽  
Supramolecular Assembly ◽  
Functional Materials ◽  
Building Blocks ◽  
Short Review ◽  
Molecular Engineering ◽  
Organic Optoelectronics ◽  
Naphthalene Diimide ◽  
Naphthalene Diimides ◽  
Derivatives Of

Naphthalene-diimide (NDI) derived building blocks have been explored extensively for supramolecular assembly as they exhibit attractive photophysical properties, suitable for applications in organic optoelectronics. Core-substituted derivatives of the NDI chromophore (cNDI) differ significantly from the parent NDI dye in terms of optical and redox properties. Adequate molecular engineering opportunities and substitution-dependent tunable optoelectronic properties make cNDI derivatives highly promising candidates for supramolecular assembly and functional material. This short review discusses recent development in the area of functional supramolecular assemblies based on cNDIs and related molecules.

scholarly journals A Sustainable Biomineralization Approach for the Synthesis of Highly Fluorescent Ultra-Small Pt Nanoclusters

Biosensors ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 128 ◽  
Author(s):  
Rajkamal Balu ◽  
Robert Knott ◽  
Christopher M. Elvin ◽  
Anita J. Hill ◽  
Namita R. Choudhury ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Photoelectron Spectroscopy ◽  
Photophysical Properties ◽  
Conformational Dynamics ◽  
Aqueous Media ◽  
Intrinsically Disordered Protein ◽  
X Ray ◽  
Pt Nanoclusters ◽  
Intrinsically Disordered ◽  
Green Fluorescent

Herein we report the first example of a facile biomineralization process to produce ultra-small-sized highly fluorescent aqueous dispersions of platinum noble metal quantum clusters (Pt-NMQCs) using a multi-stimulus responsive, biomimetic intrinsically disordered protein (IDP), Rec1-resilin. We demonstrate that Rec1-resilin acts concurrently as the host, reducing agent, and stabilizer of the blue-green fluorescent Pt-NMQCs once they are being formed. The photophysical properties, quantum yield, and fluorescence lifetime measurements of the synthesized Pt-NMQCs were examined using UV-Vis and fluorescence spectroscopy. The oxidation state of the Pt-NMQCs was quantitatively analyzed using X-ray photoelectron spectroscopy. Both a small angle X-ray scattering technique and a modeling approach have been attempted to present a detailed understanding of the structure and conformational dynamics of Rec1-resilin as an IDP during the formation of the Pt-NMQCs. It has been demonstrated that the green fluorescent Pt-NMQCs exhibit a high quantum yield of ~7.0% and a lifetime of ~9.5 ns in aqueous media. The change in photoluminescence properties due to the inter-dot interactions between proximal dots and aggregation of the Pt-NMQCs by evaporation was also measured spectroscopically and discussed.

Synthesis of 5,7-dihydroxynaphthoquinone derivatives and their reactions with nucleophiles: Nitration of 2,3-dimethylnaphthalene and subsequent transformations

1976 ◽  
Vol 29 (10) ◽  
pp. 2247 ◽  
Author(s):  
HJ Banks ◽  
DW Cameron ◽  
MJ Crossley ◽  
EL Samuel
Keyword(s):  
Unusual Reaction ◽  
Nitro Derivatives ◽  
Reactions With Nucleophiles ◽  
Derivatives Of ◽  
Related Compounds ◽  
Benzenoid Ring

5,7-Dihydroxy-2,3-dimethyl-l,4-naphthoquinone (5) and related compounds have been synthesized. The quinone affords an accessible substrate for studying an unusual reaction with nucleophiles, which involves attack at the 8-position, i.e. at the benzenoid ring. An unsuccessful approach to (5) has led to tri- and tetra-nitro derivatives of 2,3-dimethylnaphthalene. Reduction of the former and subsequent conversions have given aminonaphthoquinone and perimidinone derivatives.

scholarly journals Nitro Derivatives of 4, 5-Dimethyl-carbethoxyaminobenzene

1949 ◽  
Vol 69 (11) ◽  
pp. 493-496
Author(s):  
Taizo Matskawa ◽  
Kenzo Sirakawa
Keyword(s):  
Nitro Derivatives ◽  
Derivatives Of
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