Addition of anionic donors to the manganese(V)-oxo corrolazine complex Mn(V)(O)(TBP8Cz) has a dramatic influence on oxygen-atom transfer (OAT) reactivity with thioether substrates. The six-coordinate anionic [Mn(V)(O)(TBP8Cz)(X)](-) complexes (X = F(-), N3(-), OCN(-)) exhibit a ∼5 cm(-1) downshift of the Mn-O vibrational mode relative to the parent Mn(V)(O)(TBP8Cz) complex as seen by resonance ...

Quantification is essential to fairly compare between synthetic reactions in chemistry. Here we propose two new parameters called “adapted sensitivity constant” (ρadap) and “substrate electronics adaptability” (SEA), easily obtainable from Hammett plots, assess the ability of a (catalytic) reaction transform substrates with opposing electronics. These allow one list reactions, catalyzed or not,...

Introduced here is a quick, simple, robust method to measure acidity in ionic liquid (IL) systems by the use of the NMR-probe mesityl oxide. Acidity corresponding to a Hammett acidity of -1 to -9 can be measured reliably using this technique, a range that vastly exceeds that of any single UV-vis probe.

UiO-66-X (X = H, NH2, NO2, Br) have been successfully synthesized and tested for their photocatalytic activity in water treatment. Results show that electronic effect of the ligand substituents greatly affects the photocatalytic activity of UiO-66. The rates obtained by different substituents are linearly correlated with their Hammett coefficients.

[reaction: see text] The relative quantum yields and chemical efficiencies of crystalline p,p'-disubstituted 1,3-diphenyl-2-propanones with 4-MeO, 4-Me, 4-F, 4-CF3, and 3,4-diMeO groups were determined by parallel irradiation of polycrystalline samples. Variations in quantum yields that span a factor of 4 are analyzed in terms of the effects of substituents on the stability of the benzylic radi...

An account is given of some recent developments in the chemistry of solutions in highly associated strong protonic acid solvents, including sulphuric acid and oleums, fluorosuiphuric acid and hydrogen fluoride. Topics discussed include solvent—solute interactions, super-acid systems, Hammett acidity functions and polyatomic cations of the elements of Groups VI and VII.

The kinetics of oxidation of a number of metaand para-substituted N,α-diphenylnitrones (nitrone) by dichloramine-T (DCT) was investigated in the presence of alkali in aqueous acetonitrile medium. The order with respect to DCT was one and to OHan inverse fractional order. The reaction was first order with respect to nitrone. Both electron releasing and withdrawing substituents suppress the react...

The relative rate constants for the Rh(II)-catalyzed insertion of diazoacetone into the O-H bond have been measured through intermolecular competitions. The kinetic data were subjected to Hammett correlation analysis, and mechanistic implication of the results with respect to a stepwise vs a concerted O-H insertion pathway is discussed.

Divalent silver is stabilized in concentrated sulphuric acid and oleums. The formal redox potential of the Ag(II)/Ag(I) redox pair is markedly dependent on the Hammett acidity function and it reaches +2.90 V vs. NHE in 33% oleum thus rivalling E° for the F2/2F(-) redox pair (+2.87 V).