INVESTIGATION OF COORDINATION PROPERTIES OF 5,10,15,20-TETRA(4-OH-PHENYL) PORPHYRIN IN ACETONITRILE AND DIMETHYLFORMAMIDE

In the present work the reactions of basic interaction of 5,10,15,20-tetra(4-OH-phenyl) porphyrin in acetonitrile with the perchloric acid are studied by the method of spectrophotometric titration. And the chemical kinetics of ligand with zinc acetate in the dimethylformamide was carried out. The constant of the basic dissociation of the protonated acids of 5,10,15,20-tetra(4-OH-phenyl) porphyrin and kinetic parameters of the reaction of the formation of the zinc complex was obtained. The comparative analysis of our own obtained data and literature data according to the basic and coordination properties of 5,10,15,20-tetra(4-OH-phenyl) porphyrin and 5,10,15,20-tetrapheny porphyrin in acetonitrile and dimetilforamide in the range of 298-333K was carried out, which made it possible to draw a number of the interesting conclusions, which are concerned with the stabilization of the ionic forms of ligand in the acetonitrile and the dimethylformamide and the influence of solvent on the depth of the protonation of ligand and the kinetic rate of the formation of the corresponding zinc complexes. It is shown that the stabilization of the ionic forms of ligand upon transfer from the acetonitrile to dimethylformamide reduces the depth of the protonation of ligand, which is reflected in the decrease of the values of the dissociation constants of the cation forms of porphyrin, and the kinetic rate and the corresponding power expenditures for the reaction of the formation of ZnT(4-OH-Ph)P. It is shown that reactivity of ligand in the dipolar proton-free medium can be regulated by a change in the properties of this medium, which makes it possible to forecast the processes of the synthesis of compounds with the assigned properties.Forcitation:Plotnikova A.O., Ivanova Yu.B., Mamardashvili N.Zh. Investigation of coordination properties of 5,10,15,20-tetra(4-OH-phenyl) porphyrin in acetonitrile and dimethylformamide. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 6. P. 65-71.

Thermodynamic parameters for the basic ionization of some cyclic amines in water

The thermodynamic parameters defining the basic dissociation in water of diethylamine, cyclohexylamine, piperidine, and quinuclidine have been determined by a dilution method based on conductance measurements. The values of ΔSa0 and ΔCpa0 for the acid ionization of the corresponding ammonium ions at 25 °C are ΔSa0 −8.08, −1.24, −8.51, −13.65 cal deg−1 mol−1 and ΔCpa0 13.9, −2.7, 18.0, 4.2 cal deg−1 mol−1. The relation between these derived values and solvation changes are discussed, the apparent anomalous values of ΔCpa0 for cyclohexylamine and quinuclidine being noted, but not rationalized.

The Dissociation Constants and Conductivities of Mono-, Di- and Triethylamine in Aqueous Solution

The conductances of the mono-, di-, and triethylamines, and their hydrochlorides, in aqueous solution, have been determined. Corrections for the formation of amine carbonates and hydrolysis of the halides were made. By using the Kohlrausch law and the method of Shedlovsky and Kay, basic dissociation constants for the amines have been computed. The basic strength of this series has been found to conform to the usual trend for other series of aliphatic amines.

Basic dissociation constant for ethylamine by a convenient conductance method

A dilution technique is described which permits a determination of the ionization constant of amines by a conductance method, in a closed system. Small amounts (5–6 g) of the amine salt are required, making the method useful in studying isotope effects. Values of Ki for ethylamine over the temperature range 1.5–45.3 °C led to calculated values at 25 °C of ΔG = 4528.3 ± 0.8 cal/mole, ΔH = −266 ± 12 cal/mole, ΔS = −16.08 ± 0.04 cal/mole deg, ΔCp = −62.2 ± 1.8 cal/mole deg.