Pyropheophorbide-Fullerene Dyad: Synthesis and Photochemical Properties

Abstract

The methylpyropheophorbide-fullerene[60] dyad was synthesized by 1,3-dipolar cycloadditions of the corresponding azomethine ylide to C 60 (Prato reaction). Using the mass spectrometric method with soft matrix-activated ionization it was possible to achieve a significant reduction in fragmentation processes by the retro-Diels-Alder reaction, which allows to reliably detect the presence of polyadducts of azomethine ylide cycloadditions to fullerene. The use of gel permeation chromatography under conditions of weakening of the intermolecular π-π interaction between methylpyropheophorbide and fullerene moieties makes it possible to effectively separate mixed products with ~ 1.5 fold difference in molecular weight. It has been shown that the fluorescence of the dyad is quenched more than 5000 times (compared to the native dye). The singlet oxygen quantum yield of the dyad is 360 times less than that for the native methylpyropheophorbide a, however, its efficiency of superoxide generation increases by 18.5 times. The obtained result agrees well with the previously reported mechanism of relaxation of the excited state of the dyad through a charge-separated state, which can lead to the formation of superoxide. The observed effects indicate a change in the mechanism of photodynamic activity from type II (generation of singlet oxygen) for the native dye to type I (generation of superoxide) for the dyad, which shows a promising method of creation of highly efficient photosensitizers based on similar dye-fullerene[60] dyads.

Chlorophylls in thin-film photovoltaic cells, a critical review

“…[8][9][10][11] Such protocols serve to adapt the target product to the practical applications in various elds of medicine, biochemistry or optoelectronics. 13 Molecular structures of some chlorophyll dyes that are used as functional components of PVC are shown in Fig. 1.…”

An overview of biological applications and fundamentals of newinletandvacuumionization technologies

“…76 Rybkin et al (Institute of Problems of Chemical Physics, Chernogolovka, Russia) modified the MAI approach by guiding the matrix:analyte sample on a wire into the sub-AP region of the mass spectrometer where the ionization proceeds to characterize dyes. 77 Murray's group (Louisiana State University, Baton Rouge, LA, USA) measured particle sizes after laser ablation of LSI and other matrices, 78,79 introduced a pulsed valve ionization method in which one of the MAI matrices is knocked off a surface in close proximity to the heated mass spectrometer inlet, 80 and used MAI matrices as co-matrix for tissue analyses. 81 Halvorsen et al (University of Oslo, Oslo, Norway) demonstrated the utility of single reaction monitoring for quantitative proteomics using MAI on a triple quadrupole mass spectrometer.…”

“…Wilkins et al (University of Arkansas, Fayetteville, AR, USA) used MAI and LSI for FTICR measurements 65 and applied MAI to bacterial analyses in both positive and negative ion detection mode 76 . Rybkin et al (Institute of Problems of Chemical Physics, Chernogolovka, Russia) modified the MAI approach by guiding the matrix:analyte sample on a wire into the sub‐AP region of the mass spectrometer where the ionization proceeds to characterize dyes 77 . Murray's group (Louisiana State University, Baton Rouge, LA, USA) measured particle sizes after laser ablation of LSI and other matrices, 78,79 introduced a pulsed valve ionization method in which one of the MAI matrices is knocked off a surface in close proximity to the heated mass spectrometer inlet, 80 and used MAI matrices as co‐matrix for tissue analyses 81 .…”

Using matrix-assisted ionization method for mass spectral identification of fullerene-dye conjugates

“…Gel permeation chromatography in pyridine led to a quantitative separation of the reaction mass (with the concentration of the reaction mass of 1 mg/ml) into three main fractions: product M 3 , product M 2 , and unsubstituted fullerene with "traces" of pyropheophorbide. 8 First, the products of this reaction were analyzed using MALDI. MALDI-TOF mass spectra were taken on a Bruker Autoflex II mass spectrometer (nitrogen laser with k ¼ 337 nm, TOF resolution -18000 (FWHM)) with pyridine as the solvent and a-cyano-4-hydroxycinnamic acid (CHCA) as the matrix.…”

“…Gel permeation chromatography in pyridine led to a quantitative separation of the reaction mass (with the concentration of the reaction mass of 1 mg/ml) into three main fractions: product M 3 , product M 2 , and unsubstituted fullerene with “traces” of pyropheophorbide. 8…”