I. P. Kalashnikova

New tetra- and octa-functionalized phthalocyanines: Methods of synthesis and physicochemical properties in aqueous solutions and on solid substrates. Review

Methods of synthesis of a number of new functionalized phthalocyanines, as well as MgII, CoII, CuII, ZnII, and NiII phthalocyaninates, that involve benzo-15-crown-5-, phosphoryl-, or pyridine-containing fragments as peripheral substituents, which were developed and tested in IPCE RAS in the last five years, are reviewed and systematized. Methods of synthesis of the original phthalogens, which involve substituents of diverse composition, are considered. Results of an investigation of the aggregate states of the compounds in water and aqueous solutions of salts are generalized. The possibilities of electrostatic immobilization of the synthesized phthalocyanines in the form of self-assembled systems composed of ultrathin ionic layers on quartz and conductive glasses are considered. Based on the spectral, electrochemical, and electrocatalytic properties, the role of noncovalent interactions in the synthesis and operation of the composite systems is clarified.

Extraction of rare earths and scandium by 2-phosphorylphenoxyacetic acid amides in the presence of ionic liquids

The distribution of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Sc between aqueous solutions of their salts and solutions of 2-phosphorylphenoxy acid amides in dichloroethane containing an ionic liquid (1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide) have been studied. Metal ion extraction has been found to increase considerably in the presence of this ionic liquid in the organic phase. The stoichiometries of extractable complexes have been determined. The influence of aqueous HNO3 concentration and of the nature of extractant and ionic liquid on the efficiency of REE(III) and scandium(III) recovery to the organic phase has been considered.

Magnesium Octa(benzo-15-crown-5)phthalocyaninate in the Sodium Dodecyl Sulfate Solutions: A Study Using Electron and 1 H NMR Spectroscopy

The behavior of magnesium octa(benzo-15-crown-5)phthalocyaninate in water medium in the presence of sodium dodecyl sulfate was studied using both electronic and 1H NMR spectroscopy, including the method of two-dimensional 1H-1H correlation NOESY. In the microheterogeneous environment of the CH3(CH2)11OSO3Na solutions at the concentrations of the latter close to the CMC the phthalocyanine is in monomeric form, while at the concentration less than the critical micelle-formation concentration it becomes a dimer or even more aggregated. The results of the NMR spectroscopic investigation indicate that magnesium octa(benzo-15-crown-5)phthalocyaninate preferrably binds to the CH3(CH2)11OSO3Na micelle in the hydrophobic region of the latter.

Octa- and tetra-(benzo-15-crown-5)phthalocyanines in surfactant-containing solutions

The behavior of octa-(benzo-15-crown-5)phthalocyanine (H2cr8Pc), as well as cobalt octa- and tetra-(benzo-15-crown-5)phthalocyaninates (Cocr8Pc and Cocr4Pc), in aqueous solutions containing cationic or anionic surfactants, such as cetyl trimethylammonium bromide (CTAB), sodium carboxymethyl cellulose (Na-CMC), and sodium dodecyl sulfate (SDS), is studied using electronic spectroscopy. The presence of eight benzo-15-crown-5 ether fragments on the periphery of the phthalocyanine ring is shown to facilitate the dissolution of Pc in an aqueous environment. The interactions between CTAB and crown-containing Pc promotes the dissolution of H2cr8Pc; Cocr8Pc; and, to a lesser degree, Cocr4Pc, which is accompanied by the appearance of molecular aggregates, including heteronuclear cofacial dimers. The presence of a metal in the ring is not the necessary condition of the process. In microscopically heterogeneous medium, such as an aqueous SDS-containing solution, H2cr8Pc is present in monomeric form at SDS concentrations close to Ccr and in dimeric form at SDS content below Ccr. Under similar conditions (environment, surfactant), Cocr4Pc can exist in monomeric form at SDS concentrations much high than Ccr. The effect of the size of cation on the form of the crown-containing Pc in an aqueous solution is illustrated by an example of H2cr8Pc. Na-CMC promotes the dissolution of Pc and enables one to produce K+/Mcr8Pc-modified films from aqueous solutions.

Cyclen-containing phosphonic acids as components of osteotropic 68Ga radiopharmaceuticals

The known methods of preparation of cyclen-containing phosphonic acids, promising components of radiopharmaceuticals, have been improved, and new approaches have been developed. Application of 31Р and 13С NMR spectroscopy for initial screening of complex formation between cyclen-containing phosphonic acids and Ga3+ in D2O has been demonstrated. The conditions of 68Ga complex formation with cyclencontaining phosphonic acids and estimation of their radiochemical yield in water by means of thin-layer chromatography have been elaborated. A correlation between the NMR and TLC data has been found. Biological distribution of the selected 68Ga radiopharmaceuticals has been determined in vivo from the positron emission tomography data. The obtained standardized uptake values point at the osteotropicity of the 68Ga compounds.

Magnesium octa[(4′-benzo-15-crown-5)oxy]phthalocyaninate in water micellar solutions of sodium deoxycholate

Aggregation of magnesium octa-[(4′-benzo-15-crown-5)oxy]phthalocyaninate (Mgcr8Pc) in solutions of biocompatible anionic surfactant, sodium deoxycholate (SDC), was studied. It was shown using the electron absorption spectra that formation of Mgcr8Pc monomers in micellar solutions of SDC is affected by both increased surfactant concentration and by changes in the ionic strength of solution after sodium chloride is added. The effect of the chemical structure of biocompatible anionic surfactant on monomerization of crown-containing phthalocyanines was identified; this fact opens new possibilities for using this family of compounds for fluorescent diagnosis and photodynamic therapy.

Azamacrocyclic complexes of Group VIII metals as catalysts for oxygen electroreduction in alkaline solutions

The kinetics of catalytic electroreduction of oxygen in a 1 N KOH solution was studied by the rotating disk electrode (RDE) method. Azamacrocyclic iron and ruthenium complexes of the porphyrin and phtalocyanine series were used as catalysts. The reduction of oxygen was also studied on both the individual complexes and the same complexes supported on carbon supports (XC72R and graphene). The catalytic activity and selectivity of the complex is determined, to a high extent, by the nature and electron-donor properties of the metal atom in the complex and, to a lesser extent, by the structure of the organic ligand.

Synthesis of tetra- and octaphosphoryl-containing phthalocyanines

Phthalonitriles containing diphenylphosphoryl substituents as peripheral fragments were synthesized and characterized for the first time. The method of template assembly on the corresponding metal cation was used to obtain tetra- and octaphosphoryl-containing phthalocyaninates of Mg2+, Cu2+, and Co2+. A description is given of the method of synthesis of tetra(diphenylphosphorylmethoxy)phthalocyanine and octa(diphenylphosphoryl)methylphthalocyanine by demetallization of lithium and magnesium phthalocyaninates. The synthesized compounds were characterized using the methods of UV-, IR-, NMR 1H, NMR 31P spectroscopy and MALDI-TOF mass spectrometry.

Extraction of U(VI), Th(IV), and REE(III) from Nitric Acid Solutions with 2,6-Bis(diphenylphosphorylmethyl)pyridine N-Oxide

The extraction of microamounts of U(VI), Th(IV), and REE(III) from HNO3 solutions in the form of complexes with 2,6-bis(diphenylphosphorylmethyl)pyridine N-oxide (I) was studied in relation to the kind of organic diluent and to the HNO3 concentration in the equilibrium aqueous phase. The stoichiometry of the extractable complexes was determined. With respect to the ability to extract Th(IV) and REE(III), compound I considerably surpasses tetraphenylmethylenediphosphine dioxide and tetraalkyl-substituted analogs of I.

Solubilization of Crown-Substituted Magnesium Phthalocyaninates in Solutions of Salts of Bile Acids

Crown-containing Pc Mg[(B15C5O)8Pc], Mg[(B15C5O)4Pc], and Mg[(15C5)4Pc] are in the monomolecular state in solutions of synthetic anionic surfactants: sodium dodecylsulfate and sodium dodecylbenzenesulfonate. In micellar solutions of bile-acid salts, molecular organization of crown-substituted Pc with different methods of introduction of crown groups into the macrocycle and their different numbers changes their state from predominantly monomeric for Mg[(B15C5O)8Pc] in the presence of NaCl to the aggregated one in the case of Mg[(15C5)4Pc)]. Magnesium phthalocyaninate with annulated (15-crown-5)-fragments, Mg[(15C5)4Pc], is characterized by the highest sensitivity to the structure of the micelle-forming biocompatible surfactant.