Electronic effects of substituents on the stability of the iridanaphthalene compound [IrCp*{C(OMe)CHC(o-C6H4)(Ph)}(PMe3)]PF6

2014 ◽  
Vol 43 (46) ◽  
pp. 17366-17374 ◽  
Author(s):  
M. Talavera ◽  
J. Bravo ◽  
J. Castro ◽  
S. García-Fontán ◽  
J. M. Hermida-Ramón ◽  
...  
Keyword(s):  
Electronic Effects ◽  
Electronic Effects Of Substituents ◽  
The Stability

How do the substituents on the naphthalene skeleton affect the stability of the iridanaphthalene complex [IrCp*{C(OMe)CHC(o-C6H4)(Ph)}(PMe3)]PF6?

The stability of η2-H2borane complexes – a theoretical investigation

2014 ◽  
Vol 43 (36) ◽  
pp. 13571-13577 ◽  
Author(s):  
László Könczöl ◽  
Gábor Turczel ◽  
Tamás Szpisjak ◽  
Dénes Szieberth
Keyword(s):  
Electronic Structure ◽  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Nbo Analysis ◽  
Electronic Effects ◽  
Electronic Effects Of Substituents ◽  
New Type ◽  
The Stability ◽  
Mo Theory

A comprehensive quantum chemical study reveals the electronic structure and stability of novel η2-H2BR3complexes. The electronic effects of substituents are investigated using NBO analysis and MO theory. A new type of natural pentavalent borane compound is also presented.

scholarly journals Tautomerism of Guanine Analogues

Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 170
Author(s):  
Jakub Radek Štoček ◽  
Martin Dračínský
Keyword(s):  
Density Functional ◽  
Theoretical Calculations ◽  
Variable Temperature ◽  
Structural Fragment ◽  
Electronic Effects ◽  
Functional Theory ◽  
Electronic Effects Of Substituents ◽  
Guanine Derivatives ◽  
The Stability ◽  
Rare Tautomers

Tautomerism of nucleic acid (NA) bases is a crucial factor for the maintenance and translation of genetic information in organisms. Only canonical tautomers of NA bases can form hydrogen-bonded complexes with their natural counterparts. On the other hand, rare tautomers of nucleobases have been proposed to be involved in processes catalysed by NA enzymes. Isocytosine, which can be considered as a structural fragment of guanine, is known to have two stable tautomers both in solution and solid states. The tautomer equilibrium of isocytosine contrasts with the remarkable stability of the canonical tautomer of guanine. This paper investigates the factors contributing to the stability of the canonical tautomer of guanine by a combination of NMR experiments and theoretical calculations. The electronic effects of substituents on the stability of the rare tautomers of isocytosine and guanine derivatives are studied by density functional theory (DFT) calculations. Selected derivatives are studied by variable-temperature NMR spectroscopy. Rare tautomers can be stabilised in solution by intermolecular hydrogen-bonding interactions with suitable partners. These intermolecular interactions give rise to characteristic signals in proton NMR spectra, which make it possible to undoubtedly confirm the presence of a rare tautomer.

scholarly journals An Electrochemical Evaluation of Novel Ferrocene Derivatives for Glutamate and Liver Biomarker Biosensing

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 254
Author(s):  
Geok Hong Soon ◽  
Mary Deasy ◽  
Eithne Dempsey
Keyword(s):  
Film Studies ◽  
Redox Potentials ◽  
Signal Loss ◽  
Electronic Effects ◽  
Ferrocene Derivatives ◽  
Electroactive Films ◽  
Glutamate Oxidase ◽  
Electronic Effects Of Substituents ◽  
Glutamyl Transpeptidase

Here, we present an evaluation of two new monosubstituted ferrocene (Fc) derivatives, 3-(1H-pyrrol-1-yl)propanamidoferrocene and 1-hydroxy-2-[2-(thiophen-3-yl)-ethylamino]ethylferrocene, as glutamate oxidase mediators, together with their preparation and characterisation. Taking into consideration the influence of the electronic effects of substituents on the redox potentials of the Fc species, two candidates with pyrrole or thiophene moieties were proposed for investigation. Film studies involved potential sweeping in the presence of pyrrole or 3,4-ethylenedioxythiophene monomers resulting in stable electroactive films with % signal loss upon cycling ranging from 1 to 7.82% and surface coverage (Γ) 0.47–1.15 × 10−9 mol/cm2 for films formed under optimal conditions. Construction of a glutamate oxidase modified electrode resulted in second-generation biosensing with the aid of both cyclic voltammetry and hydrodynamic amperometry, resulting in glutamate sensitivity of 0.86–1.28 μA/mM and Km (app) values over the range 3.67–5.01 mM. A follow-up enzyme assay for liver biomarker γ-glutamyl transpeptidase realised unmediated and mediated measurement establishing reaction and incubation time investigations and a realising response over <100 U/L γ-glutamyl transpeptidase with a sensitivity of 5 nA/UL−1.

Correlation of structural parameters with antituberculotic activity in a group of 2-benzamidobenzothiazoles

1991 ◽  
Vol 56 (12) ◽  
pp. 2978-2985 ◽  
Author(s):  
Karel Waisser ◽  
Jiří Kuneš ◽  
Želmíra Odlerová
Keyword(s):  
Structural Parameters ◽  
Regression Equations ◽  
Electronic Effects ◽  
Active Compounds ◽  
Qsar Analysis ◽  
Active Structures ◽  
Benzoyl Group ◽  
Electronic Effects Of Substituents

Fourteen 2-benzamidobenzothiazole derivatives substituted in the benzoyl group and 2-cinnamamidobenzothiazole have been synthesized. The prediction of active structures by the method by Topliss gives incorrect results but, as shown on the basis of the Hansch QSAR analysis, the 2-(4-dimethylaminobenzamido)benzothiazole synthesized on the basis of the QSAR procedure by Topliss behaves anomalously also in the procedure by Hansch. Regression equations of the Hansch type have been found in which the antituberculotic activity is interpreted by lipophilicity and electronic effects of substituents. When tested in vitro, the most active compounds are comparable with ethionamide.

Transmission of the electronic effects of substituents by the thiophene ring

1974 ◽  
Vol 10 (7) ◽  
pp. 801-805 ◽  
Author(s):  
L. P. Pivovarevich ◽  
L. A. Kutulya ◽  
Yu. N. Surov ◽  
S. V. Tsukerman ◽  
V. F. Lavrushin
Keyword(s):  
Thiophene Ring ◽  
Electronic Effects ◽  
Electronic Effects Of Substituents
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