The prtnonation constant values of tryptophan were studied at 25 C. different ionic strengths. 0.1-1.0 moldm", and various ionic media of NaCIO, and N4N01, using a combination of spectrophotometrie andpotentiometric techniques. The general vend for the two protonation con Slant Vai net of tryptophan is in theorder of NaC104 > NaNO3 in different ionic media. The dependence of protonation constan...

The protonation constants of alanine and alanine methyl ester were determined in different aqueous solutions of 1,4-dioxane containing (0-50% v/v), using a potentiometric method at 25o C and constant ionic strength 0.1 mol.L-1 (NaCl). The protonation constants were analyzed in terms of Kamlet, Abboud and Taft (KAT) parameters. The results show that the effect of β is higher in comparison with t...

In this research, the protonation constant value of tannic acid was determined at 25 °C and different ionic strengths (0.1 to 0.7 mol/dm3 NaCl) using potentiometric titration technique. The dependence of protonation constant on ionic strength was modeled and discussed by a Debye-Hückel type equation. Then, based on the obtained data from experiments, the minimizing Sum o...

the formation constants of the species formed in the systems h+ + cytidine 5
-monophosphate (cmp)and h+ + cytidine 5
-monophosphate + tl (i) ion have been determined in aqueous solution in a wideph range of 1.5 to 10.5 at 25 °c and different ionic strengths ranging from 0.1 to 1.5 moldm-3naclo4, nano3, and nacl using potentiometric-spectrophotometric technique. the composition ofthe complexes w...

The macro acidity constants valid for aqueous solutions of several adenine, guanine, and hypoxanthine derivatives are summarized. It is shown how the application of the corresponding constants, e.g., for 7,9-dimethyladenine, allows a quantification of the intrinsic acidic properties of the (N1)H0/+ and (N7)H+ sites via micro acidity constants, and how to use this information for the calculation...

To connect different scale models in the multi-scale problem of microwave use, equivalent material constants were researched numerically by a three-dimensional electromagnetic field, taking into account eddy current and displacement current. A volume averaged method and a standing wave method were used to introduce the equivalent material constants; water particles and aluminum particles are us...

Infrared multiple photon dissociation action spectra of the protonated forms of the cytidyl nucleosides, 2'-deoxycytidine, [dCyd+H](+), and cytidine, [Cyd+H](+), are acquired over the IR fingerprint and hydrogen-stretching regions. Electronic structure calculations are performed at the B3LYP/6-311+G(d,p) level to determine the stable low-energy tautomeric conformations of these species generate...