Results 21 to 30 of about 1,896 (172)

From Berzelius to Hyperspace: Previously Unrecognized Network of Reactivity in Textbook Brominations

Angewandte Chemie, EarlyView.
Robotic scans across multidimensional condition spaces of classic bromination reactions uncover regions of previously unrecognized reactivity, yielding new major products and novel substitution patterns. Correlation and anticorrelation analyses of product distributions across these hyperspaces enable reconstruction of the underlying mechanistic ...
Yankai Jia, Wai‐Shing Wong, Yasemin Bilgi‐Gadina, Louis P. J.‐L. Gadina, King‐Lam Kwong, Yanqiu Jiang, Nikolaos Vagkidis, Benito Marazzi, Peter R. Schreiner, Bartosz A. Grzybowski   +9 more
wiley   +2 more sources

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 ...
openaire   +1 more source

Synthesis, Acidity Constants and Tautomeric Structure of the Diazonium Coupling Products of 2-(Benzylsulfanyl)-7H-purin-6-one in Its Ground and Excited States

Molecules, 2011
A series of new 8-arylhydrazono-2-(benzylsulfanyl)-7H-purin-6-ones 6 were synthesized, their electronic absorption spectra in different organic solvents of varying polarities were investigated and their acid dissociation constants in both the ground and ...
Hosam A. Saad, Farag M. Altalbawy, Elham S. Darwish, Mosselhi A. Mosselhi   +3 more
doaj   +1 more source

The kinetics of the reaction of 6-substituted nicotinic acids and some p-substituted benzoic acids with diazodiphenylmethane in various alcohols [PDF]

Journal of the Serbian Chemical Society, 2000
Rate constants have been determined for the reactions of diazodiphenylmethane with a number of 6-substituted nicotinic acids and p-substituted benzoic acids in twelve alcohols. A comparative study was used to evaluate and compare the Hammett r values and
MILICA M. MISIC-VUKOVIC, BRATISLAV Z. JOVANOVIC, SASA Z. DRMANIC   +2 more
doaj   +2 more sources

Theoretical Calculation of Hammett Constants for Benzoic Acid and Its Derivatives Using AM1-DFT Method

Tikrit Journal of Pure Science
The Hammett equation constants were calculated theoretically by statistically correlating the practical Hammett equation constants for these compounds with several theoretically calculated structural properties.
Abdullah Ramadan Ali, Faiz M. Hamid
doaj   +1 more source

Substituent effect on IR, 1H and 13C NMR spectral data in n-(substituted phenyl)-2-cyanoacetamides: A correlation study [PDF]

Chemical Industry and Chemical Engineering Quarterly, 2013
Linear free energy relationships (LFER) were applied to the IR, 1H and 13C NMR spectral data of N-(substituted phenyl)-2-cyanoacetamides. A variety of substituents were employed for phenyl substitution and fairly good correlations were obtained using ...
Marinković Aleksandar D., Brkić Dominik, Martinović Jelena S., Mijin Dušan Ž., Milčić Miloš, Petrović Slobodan D.   +5 more
doaj   +1 more source

Solvent free synthesis, spectral correlation and antimicrobial activities of some 2E 4′-nitrochalcones

Journal of Saudi Chemical Society, 2016
A series containing twelve substituted styryl 4′-nitrophenyl ketones have been synthesized using solvent free SiO2–H2SO4 catalysed aldol reaction under microwave condition. The yield of chalcones is found to be more than 80%.
Renganathan Arulkumaran, Rajasekaran Sundararajan, Sambandamoorthy Vijayakumar, S. Palanivel Sakthinathan, Ramamoorthy Suresh, Dakshnamoorthy Kamalakkannan, Kaliyaperumal Ranganathan, Ganesan Vanangamudi, Ganesamoorthy Thirunarayanan   +8 more
doaj   +1 more source

Synthesis, Electrochemistry and Density Functional Theory of Osmium(II) Containing Different 2,2′:6′,2″-Terpyridines

Molecules
In coordination chemistry, 2,2′:6′,2″-terpyridine is a versatile and extensively studied tridentate ligand. Terpyridine forms stable complexes with a variety of metal ions through coordination sites provided by the three nitrogen atoms in its pyridine ...
Nandisiwe G. S. Mateyise, Marrigje M. Conradie, Jeanet Conradie   +2 more
doaj   +1 more source

Dual‐Substrate Synergistic Photocatalysis: Exogenous Reagent‐Free Co‐Removal of Phenol and Cr(VI) via Electron‐Donor‐Mediated Redox Coupling over Modified Carbon Nitride

Advanced Science, EarlyView.
An exogenous reagent‐free dual‐substrate strategy harnesses phenol as an intrinsic electron donor to drive synchronous phenol degradation and Cr(VI) reduction over modified carbon nitride. π–π stacking and hydrogen bonding direct electron transfer to the catalyst, enriching photogenerated electrons and accelerating Cr(VI) reduction 6.4‐fold. This waste‐
Xiaoman Zhang, Qiyu Wang, Xiaodan Liu, Shuqi Wan, Cuiwei Du, Qilu Li, Chongfei Yu, Shuying Dong, Xianfa Su, Chun Hu   +9 more
wiley   +1 more source

Synthesis of some substituted pyrazole-1- carbothioamides and spectral correlations in 3-(2,4-dibromophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1- carbothioamides [PDF]

QScience Connect, 2013
Background: This study aims to synthesise a series of 1-thiocarbomyl pyrazolines, including 3-(2,4-dibromophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamides, using solvent-free fly-ash:PTS catalyzed cyclization between chalcones and
G. Thirunarayanan, K. G.Sekar
doaj   +1 more source