World Scientific
Skip main navigation

Cookies Notification

We use cookies on this site to enhance your user experience. By continuing to browse the site, you consent to the use of our cookies. Learn More
×

System Upgrade on Tue, May 28th, 2024 at 2am (EDT)

Existing users will be able to log into the site and access content. However, E-commerce and registration of new users may not be available for up to 12 hours.
For online purchase, please visit us again. Contact us at customercare@wspc.com for any enquiries.

Primary photoprocesses in cationic 5,10,15,20-meso-tetrakis(4-N-methylpyridiniumyl)porphyrin and its transition metal complexes bound with nucleic acids

    https://doi.org/10.1142/S108842460300094XCited by:20 (Source: Crossref)

    Photophysical properties of meso-tetrakis(4-N-methylpyridiniumyl)porphyrin (TMpyP4) and its metallocomplexes M(II)TMpyP4 (M = Zn, Cu, Ni, Co) bound to natural DNA and synthetic poly-, oligo- and mononucleotides are considered with a primary emphasis placed upon intermolecular interaction of the photoexcited porphyrins with the nearest environment. Quenching of the fluorescent S1 (but not triplet T1) state due to guanine to porphyrin electron transfer is observed for TMpyP4 intercalated between GC base pairs of the double-strand helixes, whereas in the case of TMpyP4 complexed with guanosine monophosphate (GMP) both S1 and T1 states of the porphyrin are quenched. Furthermore, a dependence of the efficiency of TMpyP4 triplet state quenching by the dissolved molecular oxygen from air on the porphyrin localization enables one to readily distinguish porphyrin groove binding mode from intercalation. Excited states of the TMpyP4 complexes with transition metals, in spite of their very short lifetimes, also interact with nucleic acid components by means of an axial ligand binding/release to/from the metal. A possible structure of the five-coordinate excited complex (“exciplex”) formed in case of CuTMpyP4 groove binding to some single- and double-strand polynucleotides is discussed.

    Most comprehensive & up-to-date research on PORPHYRINS
    Handbook of Porphyrin Science now available in 46 volumes