Журнал "Макрогетероциклы"

Vladimir P. Andreev,^a Pavel S. Sobolev,^a@ and Ekaterina A. Larkina^b

^aPetrozavodsk State University, 185910 Petrozavodsk, Russian Federation

^bMIREA – Russian Technological University, 119454 Moscow, Russian Federation

^@Corresponding author E-mail: 16862.10.ns@gmail.com

DOI: 10.6060/mhc200813s

Macroheterocycles 2021 14(2) 135-139

Based on the data on the coordination of primary, secondary and tertiary amines, as well as primary alcohols with Zn-tetraphenylporphyrin in chloroform, an increased stability of the complexes with ligands containing n-octyl groups is shown. Regularities in changes of the stability constants of complexes and thermodynamic characteristics (ΔS⁰ and ΔH⁰) (parallel to the values of lgP, which characterize the ratio of solubility of compounds in octanol and water) indicate that for primary alcohols and amines up to butanol-1 and n-butylamine, the main factor that determines the strength of the coordination interaction N→Zn is the inductive effect of the radical. However, since σ* is a constant for alkyl groups of unbranched structure containing more than three carbon atoms, further complex changes in these values indicate the action of not only electronic and steric, but also other (for example, solvation) factors. X-Ray diffraction analysis has shown that in Zn-tetraphenylporphyrin crystals with n-octylamine and di-n-octylamine of 1:1 composition, ligand molecules, bound by nitrogen atoms of amino groups to the zinc atom of one metalloporphyrin molecule. orient the hydrocarbon substituents in the space between the phenyl rings of porphyrin macrocycles of neighboring metalloporphyrin molecules. The stability constants of complexes of tertiary amines with Zn-tetraphenylporphyrin in chloroform and the reaction rate constants of pheophorbide a with n-butyl-, n-heptyl-, n-octyl-, n-nonyl-amine in chloroform and a mixture of DMF with chloroform at 30 °C were obtained by electron spectroscopy. The structure of the reaction products of the disclosure of the exocycle of pheophorbide a were proven by method of ¹H NMR spectroscopy. In chloroform, the maximum rate of opening of the exocycle of pheophorbide a is observed for n-octylamine, while in a mixture of chloroform–DMF (2:1), this amine has the lowest reactivity.

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