Structure, acidic properties and the coordination ability of sapphyrin with an unsymmetric substitution system

Abstract

Synthesis of unsymmetrically substituted 2,3,7,13,16,17,22,23-octamethyl-8,12-di-[Formula: see text]-butylsapphyrin dichloride (H5P[Formula: see text]Cl[Formula: see text] was carried out. The synthesized compound was identified by electron absorption, 1H NMR spectroscopy, and mass spectrometry. The stability of the anionic complex and the acidic properties of H5P[Formula: see text]Cl2 were studied by spectrophotometric titration. The parameters of the electronic absorption spectra and the concentration range for the existence of deprotonated forms, as well as their acid dissociation constants, are determined. The geometric structure and electronic structure of the molecular and ionic forms of the resulting sapphyrin were calculated in terms of the density functional theory (B3LYP/Def2TZVPP with an empirical correction for GD3 dispersion). The calculations showed good agreement with the experimental data.