Results 11 to 20 of about 67,257 (300)

Mutual Relations between Substituent Effect, Hydrogen Bonding, and Aromaticity in Adenine-Uracil and Adenine-Adenine Base Pairs [PDF]

Molecules, 2020
The electronic structure of substituted molecules is governed, to a significant extent, by the substituent effect (SE). In this paper, SEs in selected nucleic acid base pairs (Watson-Crick, Hoogsteen, adenine-adenine) are analyzed, with special emphasis ...
Paweł A. Wieczorkiewicz, Halina Szatylowicz, Tadeusz M. Krygowski   +2 more
doaj   +2 more sources

Vibronic Effects Analysis of the Substituent Effect on the Spectral Properties of the EMI and CPL of Three [7]Helicene Derivatives [PDF]

Molecules
The substituent effect has a significant influence on the optical properties of spectral shape, width, and wavelength, and the intensities of the maximum peaks of emission (EMI) and circularly polarized luminescence (CPL).
Qiushuang Xu, Meishan Wang, Yanli Liu
doaj   +2 more sources

Substituent Effect versus Aromaticity─A Curious Case of Fulvene Derivatives. [PDF]

J Org Chem, 2023
A computational study on amino- and nitro-substituted penta- and heptafulvenes reveals the interplay between the aromaticity and the substituent effect (SE).
Wieczorkiewicz PA, Zborowski KK, Krygowski TM, Szatylowicz H.   +3 more
europepmc   +3 more sources

Substituent Effect in the Cation Radicals of Monosubstituted Benzenes. [PDF]

Int J Mol Sci, 2021
In 30 monosubstituted benzene cation radicals, studied at the ωB97XD/aug-cc-pVTZ level, the phenyl rings usually adopt a compressed form, but a differently compressed form—equivalent to an elongated one—may coexist.
Dobrowolski JC, Dudek WM, Karpińska G, Baraniak A.   +3 more
europepmc   +2 more sources

Energetic and Geometric Characteristics of the Substituents: Part 2: The Case of NO₂, Cl, and NH₂ Groups in Their Mono-Substituted Derivatives of Simple Nitrogen Heterocycles

Molecules, 2021
Variously substituted N-heterocyclic compounds are widespread across bio- and medicinal chemistry. The work aims to computationally evaluate the influence of the type of N-heterocyclic compound and the substitution position on the properties of three ...
Paweł A. Wieczorkiewicz, Halina Szatylowicz, Tadeusz M. Krygowski   +2 more
doaj   +1 more source

Transmission of dipolar substituent effects: ionization of a series 3-(7-substituted-1-naphthyl) propynoic acid (E)-3-(7-substituted-1-naphthyl) propenoic acids and their Esterification with Diazodiphenylmethane

Al-Kitab Journal for Pure Sciences, 2023
Alkaline hydrolysis rates coefficients for the series of methyl 3-(7-substituted-1-naphthyl) propynoate was calculated in 70%v/v dimethylsulphoxide-water at various temperatures (25,30,40, and 50̊ C).
Khalaf D. F. Ghadir, Sameerah Saadoon Mustafa, Ghaidaa Neamah Kadhim, Hadeel Ahmed Hasan   +3 more
doaj   +1 more source

Naphthalene vs. Benzene as a Transmitting Moiety: Towards the More Sensitive Trifluoromethylated Molecular Probes for the Substituent Effects

Molecules, 2022
The application of DFT computational method (B3LYP/6-311++G(d,p)) to mono- and poly(CF3)substituted naphthalene derivatives helps to study changes in the electronic properties of these compounds under the influence of 11 substituents (-Br, -CF3, -CH3 ...
Adam Sokół, Henryk Koroniak, Marcin Hoffmann, Tomasz Siodła   +3 more
doaj   +1 more source

Bathochromic Shift of Fluorescence Peak in Dipyrrolo[1,2-a:2′,1′-c]quinoxaline by Introducing Each of Electron-Donating and Electron-Withdrawing Substituent

Molecules, 2023
Development of organic fluorophore is an important theme. Especially, the fluorophores with longer fluorescence peaks are useful to biological probes. One of the methods to change the fluorescence peak is the introduction of substituents.
Shoji Matsumoto, Makoto Takamori, Motohiro Akazome   +2 more
doaj   +1 more source

Influence of the Solvent on the Stability of Aminopurine Tautomers and Properties of the Amino Group

Molecules, 2023
Amino derivatives of purine (2-, 6-, 8-, and N-NH2) have found many applications in biochemistry. This paper presents the results of a systematic computational study of the substituent and solvent effects in these systems.
Anna Jezuita, Paweł A. Wieczorkiewicz, Tadeusz M. Krygowski, Halina Szatylowicz   +3 more
doaj   +1 more source

Origin of Enantioreversal in the Rhodium-Catalyzed Asymmetric Hydrogenation of Prochiral Enamides and the Effect of the α-Substituent

, 2016
The enantioselectivity of prochiral enamide hydrogenation depends on the structure of the enamide, with particular sensitivity to the nature of the α-substituent. Recently, Burk has reported a spectacular example of structure sensitivity for [Rh(DuPHOS)]+
Steven Feldgus (2401402), Clark R. Landis (1486096)   +1 more
core   +3 more sources