Ruthenium(II) and Osmium(II) Mixed Chelates Based on Pyrenyl-Pyridylimidazole and 2,2 '-Bipyridine Ligands as Efficient DNA Intercalators and Anion Sensors

Mardanya, S; Karmakar, S; Maity, D; Baitalik, S

HERO ID

3124068

Reference Type

Journal Article

Year

2015

Language

English

PMID

25539402

HERO ID 3124068
In Press No
Year 2015
Title Ruthenium(II) and Osmium(II) Mixed Chelates Based on Pyrenyl-Pyridylimidazole and 2,2 '-Bipyridine Ligands as Efficient DNA Intercalators and Anion Sensors
Authors Mardanya, S; Karmakar, S; Maity, D; Baitalik, S
Journal Inorganic Chemistry
Volume 54
Issue 2
Page Numbers 513-526
Abstract We report herein the synthesis and characterization of two monometallic ruthenium(II) and osmium(II) complexes of composition [(bpy)2M(HImzPPy)] (ClO4)2 derived from pyrenylimidazole-10-pyridin-2-yl-9H-9,11-diazacyclopenta[e]pyrene (HImzPPy) and 2,2'-bipyridine (bpy) ligands. X-ray crystallographic study shows that both crystals belong to the triclinic system having space group P1̅. The photophysical properties of 1 and 2 in acetonitrile indicate that the metal-to-ligand charge-transfer excited state is mainly centered in the [M(bpy)2](2+) moiety of the complexes and slightly affected by the extended conjugation of the pyrenylimidazole moiety. Both complexes display one-electron reversible metal-centered oxidative processes and a number of quasi-reversible reductive processes. The binding affinities of the complexes toward calf-thymus DNA (CT-DNA) were thoroughly studied through different methods such as absorption, emission, excited-state lifetime, circular dichroism, and thermal denaturation of DNA and a relative DNA binding study using ethidium bromide. All of these experiments account for the intercalative nature of both 1 and 2 toward CT-DNA as well as their light-switch behavior. The anion recognition study through different spectroscopic techniques reveals that both complexes act as "turn-on" luminescence sensors for H2PO4(-) and "turn-off" sensors toward F(-) and AcO(-). The imidazole N-H proton of the receptors gets deprotonated with the excessive addition of F(-) and AcO(-), while it interacts with H2PO4(-) through hydrogen-bonding interaction. Theoretical calculations (DFT and TD-DFT) were also performed to understand the photophysical properties of the metalloreceptors.
Doi 10.1021/ic502271k
Pmid 25539402
Wosid WOS:000348333400017
Is Certified Translation No
Dupe Override No
Comments Scopus URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921485350&doi=10.1021%2fic502271k&partnerID=40&md5=ca4d82cc03136f64c32098512ba93d0e
Is Public Yes
Language Text English