Determination of Hammett Sigma Constants by Intramolecular Hydrogen Bonding [PDF]
Nature, 1958 THE extensive literature that exists concerning Hammett's σ-constants has been subjected to several recent reviews, including a compilation and examination of available data1, a discussion of the significance and limitations of the concepts involved2, and an attempt to deduce best values and probable errors for the σ-values3.
A T Shulgin
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Donor Strengths Determination of Pnictogen and Chalcogen Ligands by the Huynh Electronic Parameter and Its Correlation to Sigma Hammett Constants [PDF]
Chemistry - A European Journal, 2019 AbstractThe suitability and accuracy of the Huynh electronic parameter (HEP) was further tested to reveal remote substituent effects in pyridines, which are located five or six bonds away from the reporter probe. These values show an excellent correlation to Hammett σ‐constants of the respective substituents with coefficients of R2=0.9856 (σm) and R2=0.
Qiaoqiao Teng, Han Vinh Huynh
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DFT study, and natural bond orbital (NBO) population analysis of 2-(2-Hydroxyphenyl)-1-azaazulene tautomers and their mercapto analouges [PDF]
Scientific ReportsTheoretical research on the keto-enol tautomerization of 2-(2-Hydroxyphenyl)-1-aza azulene (2HPhAZ) and its thiol-thione (2MPhAZ) analouge has been performed using the density functional B3LYP method with the 6–311 + + G(2d,2p) basis set in gas and ...
Shimaa Abdel Halim +3 more
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Resonance Effect in Hammett Relationship. II. Sigma Constants in Electrophilic Reactions and their Intercorrelation [PDF]
Bulletin of the Chemical Society of Japan, 1959 Yasuhide Yukawa, Yuho Tsuno
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Determination and structural correlation of pKBH+ for meta- and para- substituted benzamides in sulfuric acid solutions [PDF]
Journal of the Serbian Chemical Society, 2006 The protonation of some meta and para substituted benzamides in sulfuric acid solutions was studied by UV spectroscopy in the 190–350 nm region. Principal component analysis was applied to separate the effect of protonation from the medium effect.
EMIL POPOVSKI, GORAN STOJKOVIC
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A Web Tool for Calculating Substituent Descriptors Compatible with Hammett Sigma Constants [PDF]
Chemistry–Methods, 2021 Electron donating or accepting power of organic substituents is an important parameter affecting many properties of parent molecules, most notably their reactivity and pKa of ionizable groups. These substituent properties are usually described by Hammett sigma constants obtained by measuring ionization of substituted benzoic acids ...
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The Substituent Effect on the Radical Scavenging Activity of Apigenin
Molecules, 2018 Flavonoids widely found in natural foods are excellent free radical scavengers. The relationship between the substituent and antioxidative activity of flavonoids has not yet been completely elucidated. In this work, the antioxidative activity of apigenin
Yan-Zhen Zheng +3 more
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Synthesis, IR and NMR spectral correlations in some symmetrical diimines
Bulletin of the Chemical Society of Ethiopia, 2014 A series of diimines have been synthesized by coupling of diamine with substituted benzaldehydes. The purities of these diimines were checked by their analytical and spectroscopic data. The spectral frequencies νCN (cm-1), NMR chemical shifts (δ, ppm) of
G. Thirunarayanan
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Combining Hammett σ constants for Δ-machine learning and catalyst discovery
Digital DiscoveryWe present a simple and fast linear model for discovering organometallic catalysts for the Suzuki–Miyaura cross-coupling reaction, using a combinatorial approach.
V. Diana Rakotonirina +3 more
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New Fluorescent Probes, Their Spectroscopic Properties, and an Iterative Analysis of Their Complexation with Cyclodextrins. [PDF]
J Phys Chem BTopa-Skwarczyńska M +5 more
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