S. A. Zdanovich

Chromium(III) and Chromium(IV) Tetraphenylporphine Complexes

Stable chromium complex (AcO)CrTPP was synthesized through the reaction of meso-tetraphenylporphine with chromium(III) acetate in boiling phenol. Coordination properties of chromium porphyrin in reaction with imidazole and pyridine in o-xylene were studied by electronic absorption spectroscopy and computer modeling. A single-electron oxidation of chromium(III) complex was found to be affected by peroxide compounds. The stability of an extra complex depends on the basic properties of the extra ligand and oxidation number of the central metal atom. The complex stability correlates with the calculated energy of formation of the metal–extra ligand bond. The geometrical structure and energy parameters of hexacoordinated chromium porphyrins were calculated using the quantum-chemical method. The effect of the cis and trans position of ligands in the composition of a macrocyclic compound was established to be significant only in the extra complexes (AcO)CrTPP.

Synthesis and coordination properties of the zinc complex of dimeric porphyrin in reactions with imidazole, 2-methylimidazole, and the pyridine in benzene

Dimeric porphyrin(2,6-bis[15′-(3″,5″-di-tert-butylphenol)-3′,7′,13′,17′-tetramethyl-2′,8′,12′,18-tetraethylporphin-5′-yl]-4-tert-buthylphenol) and its binuclear zinc complex were obtained from 4,4′-dimethyl-3,3′-diethyldipyrrolylmethane, 2,6-diformyl-4-tert-butylphenol and 3,5-di-tert-buthylbenzaldehyde. Coordina-tion properties of dimeric zincporphyrin in the intermolecular reaction with nitrogen-containing bases (imidazole, 2-methylimidazole, and pyridine) in benzene were studied. Geometry and electronic structure of the zincporphyrin and its molecular complexes were calculated by a quantum-chemical method. Energy characteristics of the intermolecular reaction of the dimeric zincporphyrin with bases were determined. The calculated energies of the central metal atom interaction with the nitrogen atom of an extra-ligand agree well with the stability of the Zn-porphyrin molecular complexes. The influence of the deformation distortions of the porphyrin ligand on the strength of the metal-extra-ligand σ-bond was established.

Complexes of zinc 5,15-di(ortho-methoxyphenyl)octaalkylporphyrinate with nitrogen-containing bases

The formation of molecular complexes of zinc 5,15-di(ortho-methoxyphenyl)-2,8,12,18-tetramethyl-3,7,13,17-tetrabutylporphyrinate (ZnP) with nitrogen-containing bases L (L is imidazole, 2-methylimidazole, pyridine, 3,5-dimethylpyrazole, or dimethylformamide) in benzene is studied by spectrophotometry and computer simulation. The nature of an additional molecular ligand affects the stability of the macrocyclic complex (L)ZnP. The stability constant of this complex increases linearly with an increase in the basicity of the extra ligand and is proportional to the shift of the main absorption bands in the electronic spectra (Q(0–1), B (Soret band)). The molecular structures of zinc porphyrinate and its extra complexes are optimized by the PM3 quantum-chemical method. Their geometric and energy parameters are calculated. Correlations between the calculated energies of interaction of the central metal atom with the nitrogen atom of the extra ligand and the stability of (L)ZnP are found. The dependence of the zinc-extra ligand bond strength on the basicity of the additional molecular ligand is determined on the basis of the experimental and calculated data. The coordination properties of the compound under study are found to be affected by steric strains.

Coordination Properties of Sterically Stressed Zincporphyrins

AbstractSpectrophotometric titration and computer simulation were used to study how the nature of porphyrin and extra ligand affect the formation of extra complexes of zincporphyrins in o-xylene. The compounds under study were zincporphyrins (ZnP) with different substituents and phenyl radicals in meso-positions (zinc-5,15-(p-butyloxyphenyl)-2,8,12,18-tetramethyl-3,7,13,17-tetraethylporphyrin (ZnP1), zinc-5,15-(p-butyloxyphenyl)-2,8,12,18-tetramethyl-3,7,13,17-tetrabutylporphyrin (ZnP2), zinctetraphenylporphine (ZnP3), and zinc complexes with overlapped porphyrin (ZnP4). N-Methylimidazole, imidazole, pyridine, 3,5-dimethylpyrazole, and dimethylformamide were used as extra ligands (L). The strength of Zn–L bonding was found to decrease in extra complexes (L)ZnP in the series of ZnP as follows: ZnP4> ZnP1> ZnP2> ZnP3. It was established that the stability constant (logKst) for sterically nonstressed complexes (L)ZnP4linearly increases with growth in the extra ligand basicity (log

Reactions of (Hydroxo)(tetrakis(3,5-dicarboxy)-and (Hydroxo)(tetrakis(4,5-dicarboxy)phthalocyaninato)aluminum(III) with Sulfuric Acid: Simulation and Kinetic Experiments

K_{BH^ + }

Reaction of μ-carbido-dimeric iron(IV) octapropyltetraazaporphyrinate with dicumene peroxide and tert-butyl peroxide in benzene

) and is proportional to the shift of the main absorption bands (Δλ) in the electronic spectra of extra complexes of zinctetraphenylporphine. For spatially distorted (L)ZnP1, (L)ZnP2, and (L)ZnP3, the values of logKstand log

Intermolecular interactions of (5,15-diphenyl-3,7,13,17-tetramethyl-2,8,12,18-tetrabutylporphyrinato)manganese acetate with small organic molecules

K_{BH^ + }