S. G. Pukhovskaya

Self-Association of Sulfo Derivatives of Cobalt Phthalocyanine in Aqueous Solution

Sulfo derivatives of cobalt phthalocyanine containing naphthalene fragments have been synthesized, and their self-association and molecular complexation with pyridine in aqueous solution have been studied by spectrophotometry. The dissociation constants of the dimeric associates have been determined. The effects of the number of functional groups in the peripheral substituents and of the axial ligand on the phthalocyanine dimerization process have been revealed.

Catalytic properties of polymer matrix-immobilized cobalt complexes with sulfonated phthalocyanines

Enhancement of the catalytic activity of phthalocyanine catalysts by their immobilizing on polymer matrices has been studied. It has been found that the immobilization of sulfonated cobalt phthalocyanines on polymers enhances their catalytic activity in the oxidation of sodium diethyldithiocarbamate with air oxygen under mild conditions.

Kinetics of the formation of copper β-octaphenylporphyrin complexes in pyridine and acetic acid

The formation kinetics of copper β-octaphenylporphyrin complexes in pyridine and acetic acid is reported and is compared with that of copper β-octamethylporphyrin and dodecaphenylporphyrin complexes. The introduction of electron-donating or electron-withdrawing substituents in the β-positions of the porphyrin macrocycle change the rate of the complexation reaction by at most one order of magnitude. On passing from the planar porphyrin macrocycle to the heavily distorted one, the rate of the reaction in pyridine (electron donor solvent) and acetic acid (electron acceptor solvent) increases and decreases, respectively, by several orders of magnitude.

Catalytic properties of cobalt complexes with tetrapyrazino porphyrazine and phthalocyanine derivatives

The catalytic activity of cobalt complexes with octaphenyltetrapyrazinoporphyrazine and phthalocyanine derivatives containing branched peripheral substituents is studied in heterogeneous catalysis of the oxidation of sodium diethyldithiocarbamate (SDC) with atmospheric oxygen. Cobalt phthalocyanines are shown to display higher catalytic activity than cobalt complexes with octaphenyltetrapyrazinoporphyrazine. The highest efficiency of heterogeneous catalysts is attained at temperatures of 298–303 K.

Self-association of sulfo derivatives of cobalt phthalocyaninates in the presence of 1,4-diazabicyclo[2.2.2]octane

Complex formation between water-soluble cobalt(II) phthalocyaninates and 1,4-diazabicyclo[2.2.2]-octane has been studied. The formation of the 1: 1 molecular complex and the 2: 1 sandwich-type dimers has been confirmed. The sandwich-type dimers and the J-aggregates involving the peripheral groups of the macrocycle are formed in ethanol medium. Stability constants of the molecular complexes have been determined, and the effect of size of the peripheral substituents on the dimeric structures stability has been elucidated.

Coordination properties of molecular and anionic forms of 5,10,15,20,21-pentaphenyl-2,3,7,8,12,13,17,18-octaethylporphyrin in acetonitrile

Acid and coordination properties of 5,10,15,20,21-pentaphenyl-2,3,7,8,12,13,17,18-octaethylporphine in 1,8-diazabicyclo[5.4.0]undec-7-ene–acetonitrile system at 298 K have been studied by spectrophotometric titration. It has been found that titration causes deprotonation of nitrogen atom of the pyrrole ring to produce monodeprotonated form. Acid dissociation constant of the compound in 1,8-diazabicyclo[5.4.0]undec-7-ene–acetonitrile system at 298 K has been determined. Complexation of molecular and deprotonated forms of the ligand with silver nitrate has been studied, kinetic parameters of the corresponding reactions have been obtained. Kinetics of silver complexation with the studied ligand by ionic and molecular mechanism has been analyzed.

Investigation of Kinetics of Coordination of meso-Nitro-Substituted Derivatives of 5-Phenyl-β-octaalkylporphine with Palladium Acetate

Kinetics of the formation reactions of palladium complexes of meso-nitro-substituted 5-phenyl-β- octaalkylporphine derivatives in the Pd(OAc)2–acetonitrile system at 303–323 K was studied by spectrophotometry. The kinetic parameters of the formation reaction of complexes of porphyrins under study with palladium and zinc previously prepared, as well as their corresponding fluorescence spectra, were subjected to a comparative analysis. The parameters of electron absorption spectra of all palladium porphyrinates obtained were determined.

Porphyrin acidity and metal ion coordination revisited: electronic substitution effects

Macrocycle acidity and Zn2+ ion coordination are reported for three porphyrin derivatives which differ in both steric and electronic substitution effects on the macrocycle π-conjugated system. The role of the electronic substitution effects in the macrocycle deprotonation and metal ion chelating was found to be dominating whereas the macrocycle nonplanar distortions contribute to the acidity and metal chelation rate of the studied porphyrins in less extent. The contributions of both resonance and inductive electronic substitution effects have been distinguished based on the relationship between the weighted sum of resonance and inductive Hammett constants and the acidity and metal ion chelation rate.

Surfactant-modified polypropylene as a catalyst for oxidation of mercaptans

Surface modification of polypropylene by soluble metallophthalocyanine was performed. The effect of pretreatment of polypropylene on the degree of surface anchoring of the macrocycle was shown. The catalytic activity of the hybrid materials produced in the oxidation reaction of sodium diethyldithiocarbamate was determined.