Chernonosov A.A.,Russian Academy of Sciences |
Ermilov E.A.,Humboldt University of Berlin |
Roder B.,Humboldt University of Berlin |
Solovyova L.I.,Institute of Organic Intermediates and Dyes |
Fedorova O.S.,Russian Academy of Sciences
Bioinorganic Chemistry and Applications | Year: 2014
Water solubility of phthalocyanines (Pcs) usually increases by the introduction of charged or carboxy substituents in the peripheral positions of the macrocycle. As a result, such structural changes influence their photophysical and photochemical properties as photosensitizers. Phthalocyanines substituted with four or eight terminal carboxyl groups and having in some cases additional eight positive charges (water soluble phthalocyanines) were studied in order to evaluate the spectroscopic and photophysical effects of these side residues on the chromophore properties. The quantum yield of singlet oxygen (O 1 2) generation, the triplet-triplet absorption, and the transient absorption spectra were measured and linked to the structure of the substituents. It was shown that charged substituents did not change the quantum yields of O 1 2 generation but decrease its lifetimes. The introduction of the charged substituents not only increases the water solubility but also significantly changes absorption, fluorescence, and transient absorption spectra of water soluble Pcs. © 2014 A. A. Chernonosov et al.
Nemykin V.N.,University of Minnesota |
Makarova E.A.,University of Minnesota |
Makarova E.A.,Institute of Organic Intermediates and Dyes |
Grosland J.O.,University of Minnesota |
And 4 more authors.
Journal of Porphyrins and Phthalocyanines | Year: 2014
Magnesium 2(3),7(8),12(13),17(18)-tetraferrocenyl-5,10,15,20-tetraazaporphyrin (3), and magnesium 2(3),7(8),12(13),17(18)-tetracyano-3(2),8(7),13(12),18(17)-tetraferrocenyl-5,10,15,20-tetraazaporphyrin (4) complexes were prepared using template condensation reaction between magnesium butoxide and (Z)-dicyanovinylferrocene (1) and tricyanovinylferrocene (2), respectively. Redox and unusual optical properties of macrocyclic compounds 3 and 4 were investigated in details using UV-vis, MCD, electro-, and spectroelectrochemical methods as well as DFT and TDDFT calculations. It was shown that the HOMO in both compounds resembles Goutermans' a1u orbital (D4h symmetry), which is different from meso-ferrocenyl containing porphyrins. In both macrocycles 3 and 4 overlapping oxidation waves for ferrocene substituents were observed in electrochemical and spectroelectrochemical experiments. Electrochemically observed oxidation waves are rather broad because of the presence of positional isomers and span only ∼300 mV range in DCM/0.05 M TBAF system. Based on the excellent agreement between experimental UV-vis spectra and TDDFT predicted excitation energies, it was suggested that the low-energy NIR and visible regions are predominantly composed by the MLCT transitions with a signifcant π-π∗ mixing. Copyright © 2014 World Scientific Publishing Company.
Chernonosov A.A.,Novosibirsk State University |
Solov'eva L.I.,Institute of Organic Intermediates and Dyes |
Luk'yanets E.A.,Institute of Organic Intermediates and Dyes |
Knorre D.G.,Institute of Chemical Biology and Fundamental Medicine |
Fedorova O.S.,Novosibirsk State University
Macroheterocycles | Year: 2011
The complexes of FeII and CoII with phthalocyanines are extremely good catalysts for oxidation of organic compounds with molecular oxygen and hydrogen peroxide. Their solubility and reactivity are increased by conjugation with oligonucleotides and by formation of dimeric complexes between negatively and positively charged phthalocyanines. In our work such complexes were formed directly on single-stranded DNA through interaction between negatively charged CoII phthalocyanine in conjugate and positively charged FeII phthalocyanine in solution. The resulting oppositely charged phthalocyanine complexes showed significant increase of catalytic activity compared with monomeric forms of phthalocyanines FeII. The site-directed modification of single- and double-stranded DNA by H2O2 in the presence of dimeric complexes of negatively charged CoII and positively charged FeII phthalocyanines was detected. These complexes catalyzed the DNA oxidation with high efficacy and led to direct DNA strand cleavage. © ISUCT Publishing.