Results 11 to 20 of about 300,019 (196)
Combining Hammett σ constants for Δ-machine learning and catalyst discovery† [PDF]
Digital DiscoveryWe study the applicability of the Hammett-inspired product (HIP) Ansatz to model relative substrate binding within homogenous organometallic catalysis, assigning σ and ρ to ligands and metals, respectively.
V. Diana Rakotonirina +3 more
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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 ...
Peter Ertl, Ertl, Peter, Peter, Ertl
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The Hammett substituent constants and effects of medium
Collection of Czechoslovak Chemical Communications, 1986 The dissociation constants measured earlier for 35 substituted benzoic acids in seven solvents (water, methanol, ethanol, dimethylformamide, acetonitrile, sulfolane, and acetone) have been submitted to the principal components analysis and the factor analysis to produce sets of the Hammett substituent constants.
Oldřich Pytela +2 more
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Substituent Correlations Characterized by Hammett Constants in the Spiropyran–Merocyanine Transition
The Journal of Physical Chemistry A, 2017 The modification of molecular properties by the use of substituents is a versatile route for molecular design. Here we show for the example of multiresponsive spiropyrans that substituent effects and their correlations can be accurately described by Hammett constants, which in turn can be obtained directly from density functional theory calculations ...
Oliver Brügner +3 more
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Designing Acid Acid Co-Crystals−The Use of Hammett Substitution Constants
Crystal Growth & Design, 2009 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 R2 2(8) hydrogen-bonded heterodimer. © 2009 American Chemical Society.
Chadwick, Keith +5 more
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Quantum chemical topology (QCT) descriptors as substitutes for appropriate Hammett constants
Organic & Biomolecular Chemistry, 2005 A technique called quantum topological molecular similarity (QTMS) was recently proposed [J. Chem. Inf. Comput. Sci., 2001, 41, 764] in order to construct a variety of medicinal, ecological and physical organic QSAR/QSPRs, based on modern ab initio wave functions of geometry optimised molecules, in combination with quantum chemical topology (QCT).
Smith, P. J. +1 more
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Artificial Intelligence-Driven Inverse Design of Singlet Fission Candidates in the Acene family. [PDF]
Adv Sci (Weinh)In this work, we describe an AI‐driven inverse design platform predicting S1 and T1 energies across acenes with high accuracy. Using Hammett σ constants as descriptors and RNN models coupled with optimization algorithms, it efficiently explores ≈1014 structures, uncovering novel SF candidates from benzene to pentacene. Freely accessible at https://alba.
Uceda RG +9 more
europepmc +2 more sources
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 +4 more sources
Janus Reactivity of a Mononuclear Non-Heme Iron(III)-Peroxo Complex Toward Indole Oxidation. [PDF]
Angew Chem Int Ed EnglThe 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 ...
Zhu W, Wu P, Wang B, Ray K, Nam W.
europepmc +3 more sources