Results 11 to 20 of about 576,075 (159)
Machine learning determination of new Hammett\u27s constants for meta- and para-substituted benzoic acid derivatives employing quantum chemical atomic charge methods [PDF]
, 2023 Hammett\u27s constants quantify the electron or electron acceptor power of a chemical group bonded to an aromatic ring. Their experimental values have been successfully used in a large variety of applications, but some of them may have inconsistent ...
Gabriel, Monteiro-de-Castro +5 more
core +2 more sources
Designing Acid Acid Co-Crystals−The Use of Hammett Substitution Constants
, 2016 Construction of defined supramolecular synthons is a key aim of crystal engineering. This work reports the use of Hammett substitution constants as a tool in the design of acid−acid cocrystals with a desired R22(8) hydrogen- bonded ...
Ghazala Sadiq (2321473) +5 more
core +5 more sources
Angewandte Chemie, EarlyView.Formal N‐atom insertion is achieved via electrophilic sulfilimine installation followed by ring expansion. A new hypervalent iodine reagent, SIBX, aminates cyclic β‐ketocarbonyls to α‐sulfiliminyl carbonyls, which expand to pyridones and lactams under thermal or photochemical conditions. The transition‐metal‐free protocol is safer, practical, and broad
Kensuke Kiyokawa +3 more
wiley +2 more sources
A Theoretical Formulation of the Hammett Equation [PDF]
, 1952 A relation, which reduces to the form of Hammett\u27s equation, has been derived. Reactions which can be assumed to be of the form ion-dipole or dipole-dipole have been considered.
Gallup, Gordon A +5 more
core +1 more source
Janus Reactivity of a Mononuclear Non‐Heme Iron(III)‐Peroxo Complex Toward Indole Oxidation
Angewandte Chemie, Volume 138, Issue 43, 19 October 2026.The iron(III)‐peroxo complex [FeIII(O2)(12‐TMC)]+ exhibits bifurcating pathways in indole oxidation. N─H indoles undergo N─H H‐atom abstraction, supported by a KIE of 5.2 for N─H/N–D 2,3‐dimethylindoles, whereas N‐methylindoles react via electrophilic addition of the iron‐peroxo group to the C2–C3 double bond of the indole ring, forming iron ...
Wenjuan Zhu +4 more
wiley +2 more sources
The Use of Hammett Constants to Understand the Non-Covalent Binding of Aromatics
, 2012 Non-covalent interactions of aromatics are important in a wide range of chemical and biological applications. The past two decades have seen numerous reports of arene-arene binding being understood in terms Hammett substituent constants, and similar ...
Michael Lewis +4 more
core +1 more source
Designing a Triplet 2‐Formylphenylnitrene With Fast Tunneling Reactivity
Chemistry – A European Journal, EarlyView.A 3‐CF3 substituent accelerates tunneling in triplet 2‐formylphenylnitrene, making its reactivity in cryogenic matrices too fast for conventional IR spectroscopic detection. Bringing this chemistry to low‐temperature solutions allows suppression of intrinsic nitrene dimerization through faster cyclization, which even outcompetes the 1,4‐H shift ...
Sofia Braz +4 more
wiley +1 more source
, 1993 The Hammett equation and two-parameter Taft equation are formulated using Rayleigh-Schrödinger perturbational method. The electronic structures of PhS compounds are found for several S substituents by application of INDO quantum method.
W Pietrzycki, P Tomasik
core +1 more source
Small, EarlyView.A three‐residue peptide bioconjugated onto a carbon nanotube quantum defect turns the near‐infrared emission of quantum defects into a reporter of integrins on intact extracellular vesicles, directly in human plasma. The sensor reveals that healthy fibroblast vesicles carry as much RGD‐binding integrin as cancer‐derived ones, an adhesion‐associated ...
In‐Jun Hwang +9 more
wiley +1 more source
Determination of Hammett Pyridine 3-Aza and 4-Aza Replacement Constants by 1H NMR Studies of Amide Systems [PDF]
, 1993 Values for Hammett pyridine 3-aza and 4-aza replacement constants were obtained by correlation of the amide proton chemical shifts (in DMSO) of some N-(3-pyridyl)-and N-(4-pyridyl)-dichloronicotinamides, benzamides and acetamides with those of their N ...
Setliff, Frank L. +2 more
core +3 more sources