Jump to main content
Jump to site search

Issue 50, 2014
Previous Article Next Article

Fluorescent cyclodextrin carriers for a water soluble ZnII pyrazinoporphyrazine octacation with photosensitizer potential

Author affiliations

Abstract

A nitro-benzofurazan-triazolyl carboxymethylated β-cyclodextrin (NBFT-CMβCyD) and an oligomer of carboxymethyl β-cyclodextrin (sodium salt), crosslinked with epichlorohydrin and labeled with rhodaminyl groups (pβCyD-Rh), exhibit very high affinity in aqueous solution for octacationic photosensitizer [(CH3)8LZn]8+ neutralized by I ions (L = tetrakis-2,3-[5,6-di(2-(pyridiniumyl)pyrazino]porphyrazinato dianion). The photosensitizer (PS) forms complexes with 1 : 2 and 2 : 2 CyD:PS stoichiometry, which were characterized as binding constants and UV-Vis absorption and fluorescence properties. The self-association tendency of [(CH3)8LZn]8+, leading to a monomer–dimer equilibrium shift towards the dimer even at very low concentrations (≈10−6 M), is not contrasted by either NBFT-CMβCyD or the pβCyD-Rh oligomer, both of which completely convert the [(CH3)8LZn]8+ monomer fraction to the dimer form in the bound state. Quenching of fluorescence observed in [(CH3)8LZn]8+ upon binding with either hosts is consistent with the conversion of the monomer to the negligibly fluorescent dimer. The complexes formed with the CMβCyD units of the pβCyD-Rh oligomer have average association constants, which are larger by 6–7 orders of magnitude than those with the CMβCyD monomer in the NBFT-labeled derivative.

Graphical abstract: Fluorescent cyclodextrin carriers for a water soluble ZnII pyrazinoporphyrazine octacation with photosensitizer potential

Back to tab navigation

Supplementary files

Publication details

The article was received on 26 Nov 2013, accepted on 20 May 2014 and first published on 20 May 2014


Article type: Paper
DOI: 10.1039/C3RA47034B
Citation: RSC Adv., 2014,4, 26359-26367
  •   Request permissions

    Fluorescent cyclodextrin carriers for a water soluble ZnII pyrazinoporphyrazine octacation with photosensitizer potential

    R. Anand, F. Manoli, I. Manet, M. P. Donzello, E. Viola, M. Malanga, L. Jicsinszky, E. Fenyvesi and S. Monti, RSC Adv., 2014, 4, 26359
    DOI: 10.1039/C3RA47034B

Search articles by author

Spotlight

Advertisements