Jump to main content
Jump to site search


Bimetallic Ru(II) and Os(II) complexes based on pyrene-bisimidazole spacer: synthesis, photophysics, electrochemistry and multisignalling DNA binding studies in the near infrared region

Abstract

We report in this paper the synthesis, characterization, photophysical, electrochemical and detailed DNA binding affinities of two homobimetallic Ru(II) and Os(II) complexes derived from a new bridging ligand consisting of two pyridyl-imidazole coordinating units rigidly coupled with central pyrene moiety. Structure of the diruthenium complex was confirmed by X-ray crystallography. Both complexes exhibit luminescence at room temperature with lifetimes τ1 = 12.6 ns and τ2 = 48.8 ns for Ru(II) complex (1), while τ1 = 23.7 ns for the Os(II) complex (2) from their 3MLCT state. For 2, the luminescence maximum stretches up to NIR region which is suitable for its probable biological application. Both complexes exhibit two successive one-electron reversible metal-centered oxidations in the positive potential window. Computational studies employing DFT and TD-DFT methods were also performed to assign the experimentally observed optical spectral band in the complexes. The binding affinities of the complexes towards DNA were thoroughly investigated through a variety of techniques, viz. absorption, luminescence, excited state lifetime, circular dichroism, thermal denaturation, viscosity measurement, and relative DNA binding study using ethidium bromide. Finally, molecular docking studies were also carried out to visualize the mode of interaction between the complexes and DNA.

Back to tab navigation

Supplementary files

Publication details

The article was received on 09 Sep 2017, accepted on 09 Nov 2017 and first published on 09 Nov 2017


Article type: Paper
DOI: 10.1039/C7DT03355A
Citation: Dalton Trans., 2017, Accepted Manuscript
  •   Request permissions

    Bimetallic Ru(II) and Os(II) complexes based on pyrene-bisimidazole spacer: synthesis, photophysics, electrochemistry and multisignalling DNA binding studies in the near infrared region

    S. Baitalik, S. Mardanya and D. Mondal, Dalton Trans., 2017, Accepted Manuscript , DOI: 10.1039/C7DT03355A

Search articles by author

Spotlight

Advertisements