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Journal articles on the topic 'Hammett equation'

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Published: 4 June 2021

Last updated: 25 July 2025

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1

Liu, Lei, Yao Fu, Rui Liu, Rui-Qiong Li, and Qing-Xiang Guo. "Hammett Equation and Generalized Pauling's Electronegativity Equation." Journal of Chemical Information and Computer Sciences 44, no. 2 (2004): 652–57. http://dx.doi.org/10.1021/ci0342122.

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2

Reis, Jo�o Carlos R., Manuel A. P. Segurado, and Jaime D. Gomes De Oliveira. "Plurilinear improvement of the Hammett equation." Journal of Physical Organic Chemistry 8, no. 10 (1995): 671–88. http://dx.doi.org/10.1002/poc.610081006.

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3

P., K. BISWAS, and C. LAHIRI S. "Correlation of the Hammett Equation with the Solubility and Dissociation Constants of Benzoic Acid in Aquo-ethanolic Solutions." Journal of Indian Chemical Society Vol. 71, Sep 1994 (1994): 551–55. https://doi.org/10.5281/zenodo.5896208.

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Department of Chemistry, University of Kalyani, Kalyani-741 235 <em>Manuscript received 18 February 1993, accepted 29 July 1993</em> The correlation of solubility and the dissociation constants of benzoic acids with Hammett equation in aquo-ethanolic solutions has been attempted. The poor correlation of the solubilities with the Hammett equation arises from the difference in the factors responsible for solubilisation processes. The dissociation constants in aquo-ethanolic mixtures can be well correlated with the Hammett equation and p is found to vary linearly with the percentage of the organi

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4

Linert, W., R. Schmid, and AB Kudrjawtsev. "Concerning the Problem of the Isokinetic Relationship. III. The Temperature-Dependance of the hammett Equation." Australian Journal of Chemistry 38, no. 5 (1985): 677. http://dx.doi.org/10.1071/ch9850677.

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It is shown that the temperature-dependence of the Hammett equation is, in contrast to tradition, both physically and experimentally better described by means of temperature-dependent σ and temperature- independent ρ (termed ρo). The relationship between ρo and the customary (temperature dependent) ρ is ρT = ρo(1/T-1/Tbiso)/(1/T-1/Tbiso) where Tbiso , is the isoequilibrium temperature of the benzoic acid ionization, for which the present analysis suggests a value of -255 K, and T is 298 K. In these terms, the temperature variation of the Hammett equation can be evaluated by supplying merely E(

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5

Vandanapu, Jagannadham, та Sanjeev Rachuru. "Effect of Hetero Atom on the Hammett’s Reaction Constant (ρ) from the Physical Basis of Dissociation Equilibriums of (Dithio) Benzoic Acids and (Thio) Phenols and Its Application to Solvolysis Reactions and Some Free Radical Reactions". Advances in Physical Chemistry 2012 (3 липня 2012): 1–4. http://dx.doi.org/10.1155/2012/598243.

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The emergence of putative Hammett equation in mid 1930s was a boon to physical-organic chemists to elucidate the reaction mechanisms of several organic reactions. Based on the concept of this equation several hundreds of papers have emerged in chemical literature in the last century on the effect of structure, on reactivity, and very few on thermodynamic stability and kinetic reactivity of intermediates. In this article an attempt is made to explain the effect of hetero atom on Hammett’s reaction constant (ρ) taking the dissociation equilibriums of benzoic acids, dithiobenzoic acids, phenols,

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6

Bartoletti, Antonella, Simona Bartolini, Raimondo Germani, Gianfranco Savelli, and Clifford A. Bunton. "Hammett equation and micellar effects upon deacylation." Journal of the Chemical Society, Perkin Transactions 2, no. 4 (1994): 723. http://dx.doi.org/10.1039/p29940000723.

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7

Pytela, Oldřich, Jiří Kulhánek, Miroslav Ludwig, and Václav Říha. "Chemometrical Analysis of Substituent Effects. III. Additivity of Substituent Effects in Dissociation of 3,4-Disubstituted Benzoic Acids in Organic Solvents." Collection of Czechoslovak Chemical Communications 59, no. 3 (1994): 627–38. http://dx.doi.org/10.1135/cccc19940627.

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Sixteen 3,4-disubstituted benzoic acids (with all combinations of CH3O, CH3, Cl/Br, and NO2 substituents) have been synthesized and their dissociation constants measured in seven organic solvents (methanol, acetone, dimethyl sulfoxide, dimethylformamide, acetonitrile, pyridine, 1,2-dichloroethane). The effect of disubstitution and the validity of additive correlation relationships based on the Hammett equation have been analyzed by means of the analysis of variance, comparison of overall residual standard deviations of correlation equations of additive and additive multiplicative type, and app

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8

Alunni, Sergio, Sergio Clementi, Cynthia Ebert, et al. "Use of the Hammett equation in substituted thiophenes." J. Chem. Soc., Perkin Trans. 2, no. 4 (1985): 485–90. http://dx.doi.org/10.1039/p29850000485.

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9

Schwan, Adrian L. "Do our students really understand the Hammett equation?" Journal of Chemical Education 70, no. 12 (1993): 1001. http://dx.doi.org/10.1021/ed070p1001.

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10

Shorter, John. "ChemInform Abstract: The Prehistory of the Hammett Equation." ChemInform 31, no. 33 (2010): no. http://dx.doi.org/10.1002/chin.200033287.

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11

Weingartz, Thea, Sven Nagorny, Jörg Adams та ін. "Bis(thienyl)ethenes with α-methoxymethyl groups. Syntheses, spectroscopic Hammett plots, and stabilities in PMMA films". RSC Advances 13, № 37 (2023): 25704–16. http://dx.doi.org/10.1039/d3ra04444k.

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12

Schoustra, Sybren K., Joshua A. Dijksman, Han Zuilhof, and Maarten M. J. Smulders. "Molecular control over vitrimer-like mechanics – tuneable dynamic motifs based on the Hammett equation in polyimine materials." Chemical Science 12, no. 1 (2021): 293–302. http://dx.doi.org/10.1039/d0sc05458e.

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13

Waisser, Karel, Miloš Macháček, Jean Lebvoua, Jiří Hrbata, and Jaroslav Dršata. "Quantitative relations between chemical structure and hepatotoxicity of thiobenzamides." Collection of Czechoslovak Chemical Communications 53, no. 11 (1988): 2957–61. http://dx.doi.org/10.1135/cccc19882957.

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1H NMR chemical shifts of thioamide protons have been determined for a group of thiobenzamides, and the values obtained have been correlated with the Hammett constants. From the relations found the σm and σp values of thioamide group and some other σ constants describing the total effect of two substituents in the phenyl group have been calculated. The relation between the hepatotoxicity for rats (expressed as log ALT) and the Hammett constants is described by equation of parabola.

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14

Du, Juan, Changwei Wang, Shiwei Yin, Wenliang Wang та Yirong Mo. "Resonance-assisted/impaired anion–π interaction: towards the design of novel anion receptors". RSC Advances 10, № 59 (2020): 36181–91. http://dx.doi.org/10.1039/d0ra07877h.

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15

Domingo, Luis R., Patricia Pérez та Renato Contreras. "Electronic Contributions to the σpParameter of the Hammett Equation". Journal of Organic Chemistry 68, № 15 (2003): 6060–62. http://dx.doi.org/10.1021/jo030072j.

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16

Marrs, Peter S. "Class Projects in Physical Organic Chemistry: The Hammett Equation." Journal of Chemical Education 78, no. 4 (2001): 527. http://dx.doi.org/10.1021/ed078p527.

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17

Bragato, Marco, Guido Falk von Rudorff, and O. Anatole von Lilienfeld. "Data enhanced Hammett-equation: reaction barriers in chemical space." Chemical Science 11, no. 43 (2020): 11859–68. http://dx.doi.org/10.1039/d0sc04235h.

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18

van Beek, L. K. H. "A relationship between dipole moments and the Hammett equation." Recueil des Travaux Chimiques des Pays-Bas 76, no. 9 (2010): 729–32. http://dx.doi.org/10.1002/recl.19570760908.

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19

Huang, Jin, and H. Brian Dunford. "Oxidation of substituted anilines by horseradish peroxidase compound II." Canadian Journal of Chemistry 68, no. 12 (1990): 2159–63. http://dx.doi.org/10.1139/v90-331.

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The kinetics of oxidation of eight monosubstituted anilines catalyzed by horseradish peroxidase compound II has been studied at pH 7.00 and 7.60. With p-toluidine the rates of oxidation by compound II have been measured at 21 pH values between 3.60 and 10.25. The rate–pH profile indicates that an acidic form of compound II and the electrically neutral, unprotonated form of p-toluidine are reactive. The correlation of rate constants for the substituted anilines with the substituent constant σ in the Hammett equation suggests that the aromatic amine donates an electron to compound II in the rate

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20

S., S. S. Kushwaha, and Gupta Sandhya. "Kinetics of substitution reactions of hexacoordinate cobalt(III) complexes with phenoxyacetic acid herbicides." Journal of Indian Chemical Society Vol. 84, Mar 2007 (2007): 273–79. https://doi.org/10.5281/zenodo.5816490.

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Chemical Laboratories, P. P. N. College Campus (C. S. J. M. University), Kanpur-208 001, Uttar Pradesh, India <em>E-mail</em> : ssskushwaha4l@rediffmail.com <em>Fax</em> : 91-512-2239080 <em>Manuscript received 18 August 2006, revised 22 January 2007, accepted 29 January 2007</em> Phenoxy herbicides are proved to be potential chelating agents in the metal complexation showing substitutionreactions following second order kinetics. The reactions of <em>cis</em>-[Co(en)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>)<sup>3+</sup> with a series of substitutedphenoxyacetic acids proved to be biomolecular

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21

Urosevic, Jovica, Sasa Drmanic, Jasmina Nikolic, Ivan Juranic, and Bratislav Jovanovic. "Structure-reactivity correlation for the kinetics of the reaction of substituted 4-phenyl-1,4-dihydropyridines formation." Journal of the Serbian Chemical Society 78, no. 12 (2013): 1963–73. http://dx.doi.org/10.2298/jsc131120139u.

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Quantitative structure-reactivity correlations for the kinetics of the Hantzsch's synthesis of substituted 4-phenyl-1,4-dihydropyridines in the reaction between ethyl m- and p-substituted benzylidene acetoacetate and enamine has been studied. The reaction kinetics was followed using spectrophotometric measurements. It was found that the reaction correspond to the second-order kinetics. Quantitative structure-reactivity correlations of log k with the corresponding substituent constants (s,s+,sI and sR+) using Hammett and extended Hammett equation (DSP equation). They show linear relationship wi

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22

Ikeda, Glenn K., Karen Jang, Scott O. C. Mundle, and Andrew P. Dicks. "The Hammett Equation: Probing the Mechanism of Aromatic Semicarbazone Formation." Journal of Chemical Education 83, no. 9 (2006): 1341. http://dx.doi.org/10.1021/ed083p1341.

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23

Umarani, R., and G. Radhakrishnan. "Structure–reactivity correlations of substituted 2-phenylthiazolidines." Canadian Journal of Chemistry 70, no. 7 (1992): 2009–14. http://dx.doi.org/10.1139/v92-252.

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Systematic investigations of the kinetics of the reactions of ethyl bromoacetate (EBA) and of picryl bromide (PB) with 2-phenylthiazolidines (PT) in 100% ethanol were undertaken at 30, 35, 40, and 45 °C. The most incisive information concerning the Hammett equation comes from the extensive studies on the substituted 2-phenylthiazolidines, establishing linear Hammett plots with negative ρ values. The kinetic data, plotted in a Brønsted fashion against pKa of the corresponding thiazolidinium ions, yield linear relationships. The activation parameters were computed. The linear relationships betwe

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24

Sanjeev, Rachuru, Ramavath Ravi, Vandanapu Jagannadham, and Adam A. Skelton. "Experimental and Quantum Mechanical Study of Nucleophilic Substitution Reactions of meta- and para-Substituted Benzyl Bromides with Benzylamine in Methanol: Synergy Between Experiment and Theory." Australian Journal of Chemistry 70, no. 1 (2017): 90. http://dx.doi.org/10.1071/ch16061.

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This work involves the experimental and theoretical study of the nucleophilic substitution of meta- and para-substituted benzyl bromides with benzylamine. Conductometric rate experiments confirm the applicability of the Hammett linear free-energy relationship to this system. To gain a deep understanding of the physical chemistry at play, a quantum mechanical study of the reaction is also conducted. The quantum mechanical calculations not only reproduce the experimental free energy of activation, but also provide greater insights at the molecular and atomic level. Isolation of the calculated tr

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25

Shawali, Ahmad S., Mosselhi A. N. Mosselhi, and Thoraya A. Farghaly. "Synthesis and Tautomeric Structure of 2-arylazo-4H-imidazo[2,1-b][1,3,4]thiadiazines." Journal of Chemical Research 2007, no. 8 (2007): 479–83. http://dx.doi.org/10.3184/030823407x237885.

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Two series of the title compounds were prepared via reaction of N-aryl 2-oxohydrazonoyl halides with 1-amino-4-phenylimidazoline-2-thione. Their tautomeric structure was elucidated by spectral analysis, and the correlation of their acid dissociation constants with the Hammett equation, to be as the hydrazone form.

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26

Böhm, Stanislav, Patrik Paŕík, and Otto Exner. "Range of validity of the Hammett equation: acidity of substituted ethynylbenzenes." New Journal of Chemistry 30, no. 3 (2006): 384. http://dx.doi.org/10.1039/b512698c.

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27

Dargó, Gergő, Adrienn Bölcskei, Alajos Grün, et al. "Proton dissociation properties of arylphosphonates: Determination of accurate Hammett equation parameters." Journal of Pharmaceutical and Biomedical Analysis 143 (September 2017): 101–9. http://dx.doi.org/10.1016/j.jpba.2017.05.038.

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28

K., K. MAJUMDAR, and C. LAHIRI S. "Molecular Complexes between Chloranil and Benzoic Acids in different Solvents and Application of the Hammett Equation." Journal of Indian Chemical Society Vol. 73, Apr-May 1996 (1996): 163–67. https://doi.org/10.5281/zenodo.5883788.

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Department of Chemistry, F. C. College, Diamond Harbour-743 311 Department of Chemistry, Kalyani University, Kalyani-741 235 <em>Manuscript received 20 December 1993, revised 22 July 1994, accepted 27 July 1994</em> Stability constants for the molecular complexes of chloranil with benzoic acid and substituted benzoic acids in aliphatic hydrogen bonded solvent CHCI<sub>3</sub> and aromatic aprotic solvent C<sub>6</sub>H<sub>6</sub> have been determined. The stability constants of the substituted benzoic acid complexes have been found to be greater in CHCl<sub>3</sub> compared to those in C<sub>

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29

Elguero, José, Manuel Gil, Nerea Iza, Carmen Pardo, and Mar Ramos. "FT-IR and 13C-NMR Correlations for Some N-Substituted Azoles and Benzazoles." Applied Spectroscopy 49, no. 8 (1995): 1111–19. http://dx.doi.org/10.1366/0003702953965029.

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The FT-IR (in carbon tetrachloride) and 13C-NMR (in deuterochloroform) spectra of six p-substituted aniline derivatives, as reference compounds, and nine 1- p-aminophenyl-azoles and benzazoles were recorded. The measured spectral parameters from FT-IR were symmetric, vs(NH2), and antisymmetric, vas(NH2), stretching fundamentals and their band intensity ratio, A( vas)/ A( vs), while the corresponding 13C-NMR parameters were C-1 to C-4 chemical shifts of 1- p-aminophenyl carbons. Different IR and 13C-NMR spectral parameters and Hammett constants σp (or σp-) were correlated, and statistic analysi

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30

Pytela, Oldřich. "Chemometric Analysis of Substituent Effects. II. Relation Between Hammett Substituent Constants σm and σp and a New Model for Quantitative Description of Substituent Effects". Collection of Czechoslovak Chemical Communications 59, № 2 (1994): 381–90. http://dx.doi.org/10.1135/cccc19940381.

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The paper presents values of 25 substituent constants σi obtained by optimizing 46 data series of dissociation constants of substituted benzoic acids in various media. The constants σi fulfil the general relation between the substituent constants of the Hammett type in meta and para positions enabling the description of substituent effects from both positions at the same time by a single constant. The Hammett substituent constants are interpreted by means of the σi constants with an accuracy better than 0.03 units. In addition to it, the validity of general relationship between σp and σm was v

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31

Stankovičová, Mária, and Jozef Čižmárik. "Kinetics of alkaline hydrolysis and correlation studies of m- and p-substituted piperidinoethyl phenylcarbamates." Collection of Czechoslovak Chemical Communications 54, no. 7 (1989): 1846–53. http://dx.doi.org/10.1135/cccc19891846.

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Kinetics of alkaline hydrolysis have been studied with a series of 15 m- and p-substituted piperidinoethyl phenylcarbamates. The rate constants have been determined at 70, 60, 50, and 40 °C and the activation parameters have been calculated. These values have been correlated with the substituent constants σ, F, R, F, R, π. Validity of the Hammett equation and the Swain-Lupton equation has been confirmed in the series studied and for the p-derivatives, respectively. The lipophilicity parameter π does not correlate with the values found.

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32

Noto, Renato, Michelangelo Gruttadauria, Paolo Lo Meo, and Domenico Spinelli. "Protonation of Some 5-Substituted Di(2-thienyl) Ketones in Sulfuric Acid. A Comparison with Other 2-Thienyl and Phenyl Ketones." Collection of Czechoslovak Chemical Communications 64, no. 11 (1999): 1893–901. http://dx.doi.org/10.1135/cccc19991893.

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Protonation equilibria of some 5-substituted di(2-thienyl) ketones have been investigated spectrophotometrically in aqueous solutions of sulfuric acid at 298 K. The experimental pKBH+ values have been analyzed by means of the Hammett equation. The calculated ρ as well as the pKBH+ and m* values have been compared with those for substituted 2-acetyl- thiophenes and phenyl 2-thienyl ketones.

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33

Palát Jr., Karel, Stanislav Böhm, Gabriela Braunerová, Karel Waisser, and Otto Exner. "Reaction series not obeying the Hammett equation: conformational equilibria of substituted thiobenzanilides." New Journal of Chemistry 26, no. 7 (2002): 861–66. http://dx.doi.org/10.1039/b111156f.

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34

Zhang, Hongchang, та H. Brian Dunford. "Hammett pσ correlation for reactions of lactoperoxidase compound II with phenols". Canadian Journal of Chemistry 71, № 12 (1993): 1990–94. http://dx.doi.org/10.1139/v93-248.

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A stopped-flow kinetic study shows that the reaction rates of lactoperoxidase compound II with substituted phenols are greatly dependent upon the substituent on the benzene ring. Of the 15 phenols studied, it has been possible to relate the reaction rate constants with the ionization constants of 11 phenols by a linear Hammett free-energy relationship: (log (kX/kH) = ρσ) at pH 7.0 and 25.0 °C. The 11 m-and p-substituted phenols yield a ρ value of −2.7 ± 0.2. The data do not correlate with σ+ values using the Brown–Okamoto equation. These results can be explained by a mechanism in which the sub

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35

Ludwig, Miroslav, Oldřich Pytela, Helena Javůrková, and Miroslav Večeřa. "Analysis of substituent and solvent effects on dissociation of N-phenylbenzenesulphonamides." Collection of Czechoslovak Chemical Communications 52, no. 12 (1987): 2900–2908. http://dx.doi.org/10.1135/cccc19872900.

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The potentiometric titration in water, methanol, dimethyl sulphoxide, dimethylformamide, and acetonitrile has been used for determination of pK values of 13 N-arylbenzenesulphonamides. The validity of the Hammett and Yukawa-Tsuno models using several sets of substituent constants has been evaluated by the test to check adequacy of the regression function and by the factor analysis. It has been found that the substituent effects in solvents must be interpreted with regard to the experimental method used, solvent, set of the substituent constants, as well as the model equation ETR. The dependenc

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36

Bartnicka, H., I. Bojanowska, and MK Kalinowski. "Solvent Effect on the Hammett Reaction Constant of Substituted Benzoic Acids." Australian Journal of Chemistry 46, no. 1 (1993): 31. http://dx.doi.org/10.1071/ch9930031.

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Potentiometric titration has been used to measure dissociation constants of 13 monosubstituted benzoic acids in nitromethane, benzonitrile , acetonitrile , propylene carbonate, acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol and formamide. The reaction constants of the Hammett equation were found to depend on the solvent acidity and basicity expressed by the α and β parameters of Kamlet and Taft. The p values determined earlier in water and ethanol also obey this rule.

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37

Pytela, Oldřich, Martin Kaska, Miroslav Ludwig, and Miroslav Večeřa. "Solvolysis kinetics and mechanism of substituted 3-acetyl-1,3-diphenyltriazenes in acid medium; Kinetic acidity function." Collection of Czechoslovak Chemical Communications 52, no. 9 (1987): 2212–16. http://dx.doi.org/10.1135/cccc19872212.

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The decomposition kinetics has been measured of fourteen 3-acetyl-1,3-bis(subst. phenyl)triazenes in 40% (v/v) ethanol and sulphuric acid. The kinetic acidity function and catalytic rate constants have been determined from the rate constants observed. Mechanism has been suggested for the general acid-catalyzed solvolysis from comparison of the course of the kinetic acidity function and H0 function and from the reaction constant of the Hammett equation.

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38

Agrawal, Yadvendra K., and Nirmalya Sinha. "Thermodynamic proton-ligand stability constants of hydroxamic acids and applicability of Hammett equation." Journal of Chemical & Engineering Data 33, no. 2 (1988): 90–92. http://dx.doi.org/10.1021/je00052a007.

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39

Ludwig, Miroslav, Václav Baron, Karel Kalfus, Oldřich Pytela, and Miroslav Večeřa. "Dissociation constants of substituted benzoic acids in water and in organic solvents." Collection of Czechoslovak Chemical Communications 51, no. 10 (1986): 2135–42. http://dx.doi.org/10.1135/cccc19862135.

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Potentiometric titration has been used to measure dissociation constants of 38 monosubstituted benzoic acids in water and in 6 organic solvents (methanol, ethanol, dimethylformamide, acetonitrile, sulfolane, acetone). The results have been analyzed and interpreted from the point of view of substituent and solvent effects on the dissociation of the title substrates. It has been proved that solvents affect not only the reaction constant but also the substituent constant of the Hammett equation.

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40

Dyall, LK, and GJ Karpa. "Pyrolysis of Aryl Azides. VIII. Hammett Correlations of Rates of Pyrolysis of Substituted 2-Azidobenzophenones." Australian Journal of Chemistry 41, no. 8 (1988): 1231. http://dx.doi.org/10.1071/ch9881231.

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Eight 2-azidobenzophenones with 4- or 5-substituents have been pyrolysed in decalin solution to yield 3-phenyl-2,1-benzisoxazoles. Rate values at 100° are correlated with the Hammett substituent constants, with respect to both the azido (A) and benzoyl (B) reaction centres , and yield the equation log k = -4.38 + 2.08σ-/A -1.52σB. There is a similar equation for rates measured at 120°. Although nitro and benzoyl differ considerably in their neighbouring group abilities in azide pyrolyses, it is concluded that they exert their effects through the same mechanism. The results are consistent with

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41

Kulič, Jiří, and Aleš Ptáček. "Catalyzed Alkaline Hydrolysis of Substituted Phenyl Acetates." Collection of Czechoslovak Chemical Communications 58, no. 8 (1993): 1798–802. http://dx.doi.org/10.1135/cccc19931798.

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2-Iodosobenzoic acid forming strong nucleophile in alkaline medium - 1-oxido-1,2-benziodoxol-3(1H)-one, was used as a catalyst of alkaline hydrolysis of substituted phenyl acetates (4-NO2, 3-NO2, 3-Cl, 4-Br, H, 4-CH3, 3-CH3, 4-OCH3, 3-OCH3) in the presence of hexadecyltrimethylammonium bromide as a micellar agent. It was found that the observed first-order rate constants kobs can be correlated by the Hammett equation: log kobs = (-3.29 ± 0.03) + (1.77 ± 0.001) σ.

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42

Kulič, Jiří, Jiří Sussenbek, and Aleš Ptáček. "Alkaline Hydrolysis of Substituted Phenyl Acetates Catalyzed by Quaternary Ammonium Salts." Collection of Czechoslovak Chemical Communications 58, no. 12 (1993): 2891–95. http://dx.doi.org/10.1135/cccc19932891.

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Alkaline hydrolysis if the phenyl acetates CH3COOC6H4X (X = 4-NO2, 3-NO2, 3-Cl, H, 4-CH3, 3-CH3, and 4-OCH3) in the presence of hexadecyltris(2-hydroxyethyl)ammonium chloride, bis(2-hydroxyethyl)hexadecyl(methyl)ammonium bromide, and hexadecyltrimethylammonium bromide has been studied. Comparison of the rates of the hydrolysis for the above tenzides showed that the most efficient catalyst is the hexadecyltris(2-hydroxyethyl)ammonium chloride. In all cases, the rate data correlated well with structure effects by the Hammett equation.

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43

Milart, Piotr, та Tadeusz M. Krygowski. "Analysis of solvent and substituent effects on uv and visible spectra of N-(α-methylarylidene)-p-(N′,N′-dimethylamino)-anilines". Canadian Journal of Chemistry 63, № 11 (1985): 3256–57. http://dx.doi.org/10.1139/v85-538.

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Substituent effect on the long wave band in uv/vis spectra of p-substituted N-(α-methylarylidene)-p-(N′,N′-dimethylamino)-anilines (X = CH3O, CH3, H, Cl, and NO2) measured in eight solvents follows well the Hammett equation. Solvent effect on this band depends well on ET only for Cl- and NO2-substituted species. Both these findings support the conclusion that the long-wave band is in fact intramolecular charge transfer form the basicity center [Formula: see text] towards substituents.

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44

Keenan, Sheue L., Karl P. Peterson, Kelly Peterson, and Kyle Jacobson. "Determination of Hammett Equation Rho Constant for the Hydrolysis of p-Nitrophenyl Benzoate Esters." Journal of Chemical Education 85, no. 4 (2008): 558. http://dx.doi.org/10.1021/ed085p558.

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Makitra, R. G., and I. P. Polyuzhin. "Correlation Analysis of the Enthalpies of Vaporization of Isomers with the Hammett-Taft Equation." Russian Journal of General Chemistry 75, no. 5 (2005): 739–44. http://dx.doi.org/10.1007/s11176-005-0310-2.

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Schultz, David, and Jonathan R. Nitschke. "Designing Multistep Transformations Using the Hammett Equation: Imine Exchange on a Copper(I) Template." Journal of the American Chemical Society 128, no. 30 (2006): 9887–92. http://dx.doi.org/10.1021/ja061841u.

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Sipilä, Julius, Harri Nurmi, Ann Marie Kaukonen, Jouni Hirvonen, Jyrki Taskinen, and Jari Yli-Kauhaluoma. "A modification of the Hammett equation for predicting ionisation constants of p-vinyl phenols." European Journal of Pharmaceutical Sciences 25, no. 4-5 (2005): 417–25. http://dx.doi.org/10.1016/j.ejps.2005.04.002.

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48

Hájek, Milan, Přemysl Šilhavý, and Božena Špirková. "Reactivity of substituted styrenes in the catalytic addition reaction with the trichloromethyl radical." Collection of Czechoslovak Chemical Communications 55, no. 12 (1990): 2949–55. http://dx.doi.org/10.1135/cccc19902949.

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Abstract:

Relative reactivities have been investigated in the catalytic addition of tetrachloromethane to substituted styrenes by the competitive method. The polar effects of substituents on benzene ring were correlated with Hammett equation for a copper and ruthenium catalyst, giving ρ values equal to -0.39 and -0.18 respectively. The results indicate that in contrast to classical additions the catalytic addition of tetrachloromethane is not a free radical chain process but that the trichloromethyl radical, presumably coordinated, reacts with the carbon-carbon double bond via innersphere pathways.

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Wagnerczauderna, E., and MK Kalinowski. "Hammett-Streitwieser Reaction Constants for the Electroreduction of Diaryl Ketones in Aprotic Media." Australian Journal of Chemistry 49, no. 8 (1996): 901. http://dx.doi.org/10.1071/ch9960901.

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Cyclic voltammetry has been used to measure formal potentials of seven aromatic ketone/ketyl radical anion systems in benzonitrile, acetonitrile , propylene carbonate, acetone, N,N- dimethylformamide, N-methylpyrrolidin-2-one, dimethyl sulfoxide and hexamethylphosphoric triamide. The values measured in each solvent obey the Hammett- Streitwieser equation; the reaction constants were found to depend on the solvent acidity and basicity expressed by acceptor and donor numbers, respectively. The results are discussed in terms of the solvation of the products and reactants of the electrode reaction

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Darugar, Vahidreza, Mohammad Vakili, Sayyed Faramarz Tayyari, Fadhil Suleiman Kamounah, and Raheleh Afzali. "Application of Hammett equation to intramolecular hydrogen bond strength in para-substituted phenyl ring of trifluorobenzoylacetone and 1-aryl-1,3-diketone malonates." European Journal of Chemistry 9, no. 3 (2018): 213–21. http://dx.doi.org/10.5155/eurjchem.9.3.213-221.1713.

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The stability of two stable cis-enol forms in two categories of β-diketones, including para-substituted of trifluorobenzoylacetone (X-TFBA) and 1-aryl-1,3-diketone malonates (X-ADM, X: H, NO2, OCH3, CH3, OH, CF3, F, Cl, and NH2) has been obtained by different theoretical methods. According to our results, the energy difference between the mentioned stable chelated enol forms for the titled compounds is negligible. The theoretical equilibrium constants between the two stable cis-enol of the mentioned molecules are in excellent agreement with the reported experimental equilibrium constant. In ad

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