Loading…

Improving the Photosensitizing Properties of Ruthenium Polypyridyl Complexes Using 4‑Methyl-2,2′-bipyridine-4′-carbonitrile as an Auxiliary Ligand

We report in this work the synthesis and spectroscopic, electrochemical, spectroelectrochemical, and photophysical characterization of a novel series of ruthenium polypyridyl complexes with 4-methyl-2,2′-bipyridine-4′-carbonitrile (Mebpy-CN) as an auxiliary ligand of general formula [Ru(bpy)3–x (Meb...

Full description

Saved in:
Bibliographic Details
Published in:Inorganic chemistry 2013-05, Vol.52 (9), p.4950-4962
Main Authors: Ortiz, Juan H. Mecchia, Vega, Nadia, Comedi, David, Tirado, Mónica, Romero, Isabel, Fontrodona, Xavier, Parella, Teodor, Vieyra, F. Eduardo Morán, Borsarelli, Claudio D, Katz, Néstor E
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We report in this work the synthesis and spectroscopic, electrochemical, spectroelectrochemical, and photophysical characterization of a novel series of ruthenium polypyridyl complexes with 4-methyl-2,2′-bipyridine-4′-carbonitrile (Mebpy-CN) as an auxiliary ligand of general formula [Ru(bpy)3–x (Mebpy-CN) x ](PF6)2 (x = 1–3) (with bpy = 2,2′-bipyridine). A significant increase in the lifetime and quantum yield of emission of the lowest 3MLCT excited state is disclosed when going from x = 1 to x = 3, evidencing an improvement of the photosensitizing properties with respect to [Ru(bpy)3](PF6)2. Furthermore, quenching by molecular oxygen of 3MLCT excited states of the three complexes produced singlet molecular oxygen (1O2) with quantum yield values higher than that of [Ru(bpy)3]2+ in CH3CN. The structure of the complex with x = 1 has been determined by X-ray diffraction. The photoconductivity of ZnO nanowires covered with this same complex is increased by an order of magnitude, pointing to its feasibility as a component of a DSSC. A new dinuclear complex with Mebpy-CN as a bridging ligand has also been prepared and characterized by physicochemical techniques. The derived mixed-valent species of formula [(bpy)2RuII(Mebpy-CN)RuIII(NH3)5]5+ displays a considerable metal–metal electronic coupling due to the delocalization effect of a nitrile group in the 4′ position of the bpy ring.
ISSN:0020-1669
1520-510X
DOI:10.1021/ic302594b