A "V"-shaped Hammett plot shows that resonance-assisted hydrogen bonding does not dictate the strength of the intramolecular hydrogen bond in the E isomers of hydrazone-based switches because it involves an aromatic pyridyl ring.

Substituent effects on the physical properties and pKa of phenol were studied using density functional theory [B3LYP /6-311G(d,p)] calculations. Substituents alter the physical properties of phenol such as the hydroxyl-group C-0 and 0-H bond lengths, the C-0-H bond angle, and the energy barrier to rotation about the C-0 bond, and also influence the hydroxyl-group pK •. Except for the rotational...

Linear free energy relationships (LFER) were applied to the IR, Hand C-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 the simple Hammett and the Hammett–Taft dual substituent parameter equations. The correlation results of the substituent induced C-NMR chemical shifts...

A series of molybdenum(vi) cis-dioxo complexes containing tetradentate salan ligands with different para-substitutions on the phenoxy group have been prepared. These complexes catalyse the oxygen atom transfer reaction between dimethylsulfoxide and triphenylphosphine. During oxo transfer catalysis, the complexes are resistant to formation of catalytically inactive oxo-bridged dimeric Mo(v) comp...

In an inorganic material, a measure of the Lewis basicity of a solvent is commonly provided by the optical basicity, i.e. the ability of the solvent molecules to donate their electrons to an acidic species. This quantity is known to vary with the polarizability of the Lewis base. In protic solvents, the Lewis definition of basicity is barely used; it is replaced by the more purpose-built Brønst...

Historically, Hammett constants have been extremely effective in describing the influence of substituents on chemical reactivity and other physical and chemical properties, whereas variables derived from quantum chemical calculations have generally been less effective. Taking the experimental pK(a)s of substituted anilines as a representative physicochemical property, five ab initio quantum che...

In order to find the susceptibility of the Claisen rearrangement and next proton shift reaction of ally) aryl etherto the substiment effects in pan position, the kinetic and the:rmodynamie parameters are calculated at The33 LTP level using 6-3110. b asis set. The calculated activation energies for the rearrangements and protonshift reactions are around 3133 kcaUmol and 52.16 kcal/mol, nap.. liv...