scholarly journals Natural Flavonoids Interact with Dinitrobenzene System in Aprotic Media: An Electrochemical Probing

2012 ◽  
Vol 7 (3) ◽  
pp. 1934578X1200700
Author(s):  
Nasima Arshad ◽  
Naveed K. Janjua ◽  
Athar Y. Khan ◽  
Azra Yaqub ◽  
Torsten Burkholz ◽  
...  
Keyword(s):  
Reduction Potential ◽  
Intramolecular Hydrogen Bonding ◽  
Quantum Mechanical ◽  
Carbon Electrode ◽  
Electrochemical System ◽  
Cyclic Voltammetric ◽  
Anodic Peak Current ◽  
Acidic Nature ◽  
Intramolecular Hydrogen ◽  
Semi Empirical

Three structurally related natural flavonoids (FlOH), quercetin (Q), rutin (R) and morin (M), were investigated by cyclic voltammetry to probe their interactions with hazardous 1,4-dinitrobenzene (1,4-DNB) using a glassy carbon electrode. Scavenging of 1,4-DNB by FlOH was inferred from a positive shift in reduction potential, decrease in anodic peak current, and irreversible electrochemical behavior of 1,4-DNB on increasing the flavonoid concentration. The homogeneous bi-molecular rate constant (k2) was determined using the Nicholson-Shain equation and found to be higher for the dianion. Morin posed a comparatively higher k2 value for its interaction with the 1,4-DNB electrochemical system owing to its more acidic nature and least intramolecular hydrogen bonding. The cyclic voltammetric (CV) results were further supported by HyperchemPM3 quantum mechanical semi-empirical calculations, which point towards ErCi interactions between flavonoids and 1,4-DNB. The present investigation is biologically significant in terms of natural flavonoidal scavenging activity toward toxins such as dinitroaromatics.

Crystal Structure and Tautomerism of 1-[N-(4-Iodophenyl)]aminomethylidene-2(1H)naphthalenone

2001 ◽  
Vol 56 (10) ◽  
pp. 1003-1008 ◽  
Author(s):  
H. Ünver ◽  
M. Kabak ◽  
D. M. Zengin ◽  
T. N. Durlu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Quantum Mechanical ◽  
Monoclinic Space Group ◽  
Quantum Mechanical Calculations ◽  
X Ray ◽  
H Nmr ◽  
Mechanical Methods ◽  
Intramolecular Hydrogen ◽  
Semi Empirical

1-[N-(4-Iodophenyl)]aminomethylidene-2(1H)naphthalenone (1) (C17H12NOI) has been studied by X-ray analysis, IR, 1H NMR, UV and AM1 semi-empirical quantum mechanical methods. It crystallises in the monoclinic space group P21/n with a = 4.844(3), b = 21.428(2), c = 13.726(2) Å, ß = 93.07(2)° (R1 =0.032 for 4132 reflections [I > 2σ(I)]). The title compound is not planar and an intramolecular hydrogen bond connects O1 and N1 [2.530(4) Å]. Complementary IR, 1H NMR and UV measurements out. Tautomerism and conformations of the title semi-empirical quantum mechanical calculations and the results are compared with the X-ray data.

scholarly journals Intramolecular hydrogen bonding and conformational preferences on 2-fluoro-phenylaminocyclohexanol

2018 ◽  
Author(s):  
Cassia Chiari ◽  
Claudio Francisco Tormena ◽  
Kahlil Schwanka Salome ◽  
Laiza Bruzadelle Loureiro ◽  
Renan Vidal Viesser
Keyword(s):  
Hydrogen Bonding ◽  
Driving Force ◽  
Conformational Stability ◽  
Intramolecular Hydrogen Bonding ◽  
Quantum Mechanical ◽  
Resonance Spectroscopy ◽  
Quantum Mechanical Calculations ◽  
Conformational Preferences ◽  
Intramolecular Hydrogen ◽  
Theoretical Results

The aim of this study is to evaluate the influence and strength of possible intramolecular hydrogen bonding (IntraHB) involving N-H--O, O-H--N, O-H--F and N-H--F molecular moieties as a driving force on the conformational preferences of 2-fluoro-phenylaminocyclohexanol. To achieve our purpose we synthesized the compound and performed it's characterization using Nuclear Magnetic Resonance Spectroscopy (NMR). Quantum mechanical calculations were carried out to evaluate the effect of IntraHB on the conformational stability. Experimental and theoretical results showed that N-H--F and O-H--N IntraHB have a greater influence on the conformacional preferably adopted by the molecule.

scholarly journals A New Cr3+ Electrochemical Sensor Based on ATNA/Nafion/Glassy Carbon Electrode

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2695
Author(s):  
Reda M. El-Shishtawy ◽  
Mohammed M. Rahman ◽  
Tahir Ali Sheikh ◽  
Muhammad Nadeem Arshad ◽  
Fatimah A. M. Al-Zahrani ◽  
...  
Keyword(s):  
Electrochemical Sensor ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Dynamic Range ◽  
Condensation Reaction ◽  
Intramolecular Hydrogen Bonding ◽  
Spectroscopic Techniques ◽  
Carbon Electrode ◽  
Heavy Metal Cations ◽  
Intramolecular Hydrogen

A new electrochemical sensor of metal cation in an aqueous solution based on homobifunctional tridentate disulfide Schiff base and named 1,1′-(-((disulfanediylbis(2,1-phenylene))bis(azaneylylidene))bis(methaneylylidene))bis(naphthalene-2-ol) (ATNA) was easily obtained quantitatively from the condensation reaction of 2-hydroxy-1-naphthaldehyde and 2-aminothiophenol, and then fully characterized by spectroscopic techniques for structure elucidation. The molecular structure of ATNA was also confirmed by a single-crystal X-ray diffraction study to reveal a new conformation in which the molecule was stabilized by the O–H…N type intramolecular hydrogen bonding interactions in both moieties. The ATNA was used as a selective electrochemical sensor for the detection of chromium ion (Cr3+). A thin film of ATNA was coated on to the flat surface of glassy carbon electrode (GCE) followed by 5 % ethanolic Nafion in order to make the modified GCE (ATNA/Nafion/GCE) as an efficient and sensitive electrochemical sensor. It was found to be very effective and selective against Cr3+ cations in the company of other intrusive heavy metal cations such as Al3+, Ce3+, Co2+, Cu2+, Ga3+, Hg2+, Mn2+, Pb2+, and Y3+. The detection limit at 3 S/N was found to be 0.013 nM for Cr3+ ions within the linear dynamic range (LDR) (0.1 nM–10.0 mM) of Cr3+ ions with r2 = 0.9579. Moreover; this work instigates a new methodology for developing the sensitive as well as selective electrochemical toxic cationic sensors in the field of environmental and health care.

scholarly journals Synthesis, spectroscopic studies and electrochemical properties of Schiff bases derived from 2-hydroxyaldehydes and phenazopyridine hydrochloride

2013 ◽  
Vol 78 (6) ◽  
pp. 795-804 ◽  
Author(s):  
Sultan Yagmur ◽  
Selehattin Yilmaz ◽  
Gulsen Saglikoglu ◽  
Murat Sadikoglu ◽  
Mustafa Yildiz ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Electrochemical Reduction ◽  
Schiff Bases ◽  
Glassy Carbon ◽  
Reduction Potential ◽  
Spectroscopic Studies ◽  
Spectroscopic Techniques ◽  
Carbon Electrode ◽  
Reduction Mechanism ◽  
Cyclic Voltammetric

Novel Schiff bases (1-4) were synthesized by the reaction of 2-hydroxybenzaldehyde, 2-hydroxy-5-methoxybenzaldehyde, 2-hydroxy-5-nitrobenzaldehyde, 2-hydroxy-1-naptaldehyde with phenazopypridine hydrochloride (PAP) and their structures were elucidated by means of spectroscopic techniques. The electrochemical reduction of PAP and its Schiff bases (1-4) were carried out on glassy carbon electrode (GCE) in dimethyl sulfoxide (DMSO) using the cyclic voltammetric (CV) technique. The effect of functional groups on reduction potential of Schiff bases was investigated. A general electrochemical reduction mechanism of the compounds was also suggested.

scholarly journals N-Benzoyl / (4-nitrobenzoyl)-N'-4-cyanophenyl thioureas

2018 ◽  
Author(s):  
Fatma Aydin
Keyword(s):  
Glassy Carbon ◽  
13C Nmr ◽  
Functional Group ◽  
Reduction Potential ◽  
High Yield ◽  
Spectroscopic Methods ◽  
Carbon Electrode ◽  
Cyclic Voltammetric ◽  
Elementary Analysis ◽  
Ft Ir

Herein, two title compounds, N-Benzoyl-N’-4-cyanophenyl thiourea (I) and N-(4-nitrobenzoyl)-N’-4-cyanophenyl thiourea (II) were synthesized in high yield, via aroyl isocyanate and 4-aminobenzonitrile. The structure of the prepared compounds was characterized by elementary analysis and FT-IR, 1H, 13C NMR spectroscopic methods. Cyclic voltammetric (CV) experiments were performed with glassy carbon electrode. The reduction potential values of different functional group such as nitro, cyano in title compounds were investigated using CV curves.

Theoretical study of intramolecular hydrogen bonding and molecular geometry of 2-trifluoromethylphenol

10.1002/jcc.2 ◽  
1996 ◽  
Vol 17 (16) ◽  
pp. 1804-1819 ◽  
Author(s):  
Attila Kov�cs ◽  
Istv�n Kolossv�ry ◽  
G�bor I. Csonka ◽  
Istv�n Hargittai
Keyword(s):  
Hydrogen Bonding ◽  
Theoretical Study ◽  
Molecular Geometry ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Hydrogen
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