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The effect of tetra-β-phenyl substitution on the acid-base properties of the porphyrazine macroring was studied by theoretical and experimental methods. [ABSTRACT FROM AUTHOR]

Indium complex of 13,17-dibutyl-2,3,7,8,12,18-hexamethyl-5-azaporphyrin (Cl)InMAP was synthesized, and acid-base interactions of themeso-nitrogen atoms in (Cl)InMAP and its diaza analog (Cl)InDAP with acetic and trifluoroacetic acids were studied by1H NMR and electronic spectroscopy. Depending on the medium, the complexes and proton-donor species HA give rise to acid solvates>N···(HA)n which are converted to final acid-base interaction products, H-complexes>N···H+···A-(HA)m or ionic associates>NH+···A-(HA)l , as the acidity of the medium rises. In acetic acid solution, the acid solvates derived from more basic (Cl)InMAP exist in equilibrium with the H-associates (pKa1 = 4.45±0.03). From (Cl)InDAP, the corresponding H-associates are formed only in the presence of H2SO4 (pKa1 = 2.10±0.03). In more polar media (solutions of trifluoroacetic acid in methylene chloride), ionic associates are formed, which involve one [(Cl)InMAP, pK1 = 2.46±0.02] or twomeso-nitrogen atoms [(Cl)InDAP, pK1 = 2.11±0.03, pK2 = 0.41±0.04). [ABSTRACT FROM AUTHOR]

Stability constants were determined for acid forms of octa(4-chloromethylphenyl)-, octa(4-bromophenyl)-, and octa(4-nitrophenyl)tetraazaporphyrins, formed by acid-base interactions in H2SO4-CH3COOH mixtures. The probability of formation of each form depends not only on the electronic structure of the molecule, but also on the composition and properties of the medium. [ABSTRACT FROM AUTHOR]

The article focuses on a study related to examining the acid-base properties, deselenation and synthesis of 5,6,8,9,11,12-Hexakis(4-tert-butylphenyl)[1,2,5]selenadiazolo[3,4-b]porphyrazine, a macrocyclic compound, published in a 2013 issue of the "Russian Journal of Organic Chemistry."