Physicochemical properties of π-π complexes of zinctetraphenylporphyrin with aromatic molecules

Features of the solvation of zinctetraphenylporphyrin (ZnTPP) in benzene, toluene,ortho-, meta-, andpara-xylenes were studied by a thermogravimetric method. The temperature ranges of the stability and the compositions of the corresponding specific - complexes were determined from the results of the thermogravimetric investigation of the crystallosolvates of the metalloporphyrin with the solvent molecules, and the energy characteristics of the intermolecular metalloporphyrin—solvent interactions were calculated.Institute of the Chemistry of Nonaqueous Solutions, Russian Academy of Sciences, 153018 Ivanovo. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1545–1548, July, 1992.     

Effect of the complex forming ion on the physicochemical characteristics of solvation of tetraphenylporphine complexes

The enthalpies of dissolution, transfer, and axial coordination for the Cd(II), Co(II), Mn(III), Fe(III), and Cr(III) complexes of tetraphenylporphine, H₂(TPP), in nonpolar (C₆H₆, CCl₄) and electron-donating solvents (DMF, DMSO, Py,c-C₅H₁₀NH) have been determined calorimetrically at 298.15 K. On the basis of thermogravimetrical data for the corresponding crystallosolvates the composition, thermal stability, and energy of intermolecular interaction of the metal-porphine complexes with pyridine have been calculated. Complexing in noncoordinating solvents brings about no radical change in the physicochemical characteristics of axial coordination which depend critically on the electron structure of the complex-forming metal.Translated fromfzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 846–850, May, 1993.     

Electronic Absorption Spectra of Alkyl-Substituted Dipyrromethenes and Biladienes-a,c in Organic Solvents

3,3',5,5'-Tetramethyl-4,4'-dibutyldipyrromethene-2,2' and 1,3,7,13,17,19-hexamethyl-2,8,12,15-tetrabutylbiladiene-a,c hydrobromides undergo deprotonation in electron-donor solvents or in the presence of nucleophilic reagents. The rate and depth of the process depend on the electron-donor properties of the solvent, concentration, and degree of self-association of the chromophore molecules. Under analogous conditions, partial decomposition of the biladiene-a,c chromophore occurs.     

Direct Phenylamination of 6-Aminonaphthacenequinones Promoted by Metal Salts

6-Amino-5,12- and -5,11-naphthacenequinones react with aniline in the presence of cobalt, copper, and manganese salts, resulting in replacement of hydrogen in the peri-position with respect to the carbonyl group by phenylamino group and formation of 11- and 12-phenylamino-6-amino(phenylamino)-5,12- and -5,11-naphthacenequinones.     

Thermodynamics of Donor-Acceptor Interaction of Tetraphenylporphyrinatozinc with Amides and Dimethyl Sulfoxide

Thermodynamic parameters of complex formation of alkylamides and dimethyl sulfoxide with tetraphenylporphyrinatozinc in benzene and carbon tetrachloride were determined by calorimetric titration. The composition of the complexes was also determined. Correlations were found between thermodynamic stability parameters of the complexes and physical parameters of the ligands. The effect of the ligand and solvent nature on the thermodynamics of complex formation was analyzed.     

Some peculiarities of π—π interactions between tetraphenylporphine metal complexes and aromatic solvents

The — complexes of metal tetraphenylporphinates with benzene, toluene, and xylenes were characterized by means of thermogravimetry. The ability of metalloporphyrins to form — complexes with certain -donor molecules depends largely on the -acceptor capacity of the macroheterocycle, and on the peculiarities of the metal—porphyrin coordinative linkage. Stoichiometry, energy parameters, and thermal stability of the - complexes of metalloporphyrins with various aromatic ligands are determined to a great extent by the molecular structure of solvents.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp.850–853, May, 1993.     

Thermodynamics of Copper(II), Zinc(II), Cobalt(II), Mercury(II), and Nickel(II) Complexation with α,α-Dipyrrolylmethene in DMF

Thermodynamics of complexation reactions between Zn(II), Ni(II), Hg(II), Co(II), and Cu(II) acetates and 3,35,5-tetramethyl-4,4-dibutyldipyrrolylmethene in DMF at 298.15 K is studied by calorimetric and spectrophotometric methods. The replacement of Zn²⁺, Ni²⁺, and Hg²⁺ ions by Co²⁺ and Cu²⁺ ions was found to increase the equilibrium constants of reactions of complex formation with dipyrrolylmethene by more than two orders of magnitude. The role of solvation interactions in coordination of dipyrrolylmethene by d-metal ions is established.     

Synthesis and Acylation of peri-Amino Derivatives of Anthra[1,9-cd]pyrazol-6-one

Heating of 5- and 7-chloro-6H-anthra[1,9-cd]pyrazol-6-ones in butylamine and aniline gives the corresponding peri-amino-substituted anthrapyrazole derivatives. Acylation of the latter occurs at the N¹ atom of the heterocyclic fragment to afford monoacyl derivatives having an ana-quinonimine structure.