Near-infrared room temperature emission from a novel class of Ru(ii) heteroleptic complexes with quinonoid organometallic linker

Abstract

A novel class of luminescent octahedral ruthenium complexes 2-4 displaying a π-bonded quinonoid ligand is described. Remarkably, the presence of this organometallic ligand affects their UV-vis properties and transforms them into panchromatic absorbers. Furthermore, it turns on room temperature NIR emissions.

A Convenient Approach to Luminescent Cyclometalated Platinum(II) Complexes with Organometallic π‐Bonded Benzenedithiolate

“…More recently we have reported the synthesis of organometallic π‐bonded quinones [Cp*M(η‐C 6 H 4 O 2 )] n (M = Ru, n = –1; M = Rh, Ir, n = 0) and their usage as organometallic ligands for the preparation of a unique type of supramolecular assemblies with useful luminescence properties . Since this metal‐based‐ligand approach proved to be very effective in the modulation of electronic properties of the Ru(polypyridyl), Pt(terpy) and Pt(bpy) chromophores, we sought to prepare the related π‐bonded benzenedithiolate complex [Cp*Ru(η‐C 6 H 4 S 2 )] – ( 1 ) and use it as a tuned sulfur‐containing ligand towards square planar platinum chromophore, which, according to Pearson's HSAB concept, is considered as a soft metal ion preferring coordination by soft ligand such as 1 . The presence of the Cp*Ru moiety at the arene ring of the benzenedithiolate allows also a fine tuning of the electronic donating properties of the sulfur centers which stabilizes the HOMO levels , .…”

Functionalized o-Quinones: Concepts, Achievements and Prospects

“…From this point of view a topology of ligand that provides an opportunity for synthesis of coordination polymers or an ordering of the molecules in the crystal phase may be very useful. o-Quinone itself might be a bridging ligand in case of binding of metal ions both by dioxolene site and by π-complexation with diene system [5][6][7][8][9][10]. The chemistry of o-quinones is immensely rich and diverse, so there are many ways to functionalize an o-quinone molecule.…”

“…These data correlate well with the electrochemical properties of pdon and phen-Q: the oxidation capacity of 1,10-phenanthroline-5,6-dione is higher than that of 9,10-phenanthrenequinone. Cr(CO) 6 and Mo(CO) 6 react with pdon towards the dioxolene site to give corresponding tris(o-semiquinonate) complexes [27]. Reaction of pdon with bis(arene)titanium and vanadium complexes also proceeds as an oxidative addition to the dioxolene site.…”

Aggregation and Supramolecular Self-Assembly of Low-Energy Red Luminescent Alkynylplatinum(II) Complexes for RNA Detection, Nucleolus Imaging, and RNA Synthesis Inhibitor Screening

“…Low-energy red to near-infrared (NIR) luminescent materials have extensive applications in chemistry and biology and are especially attractive for application in biological imaging. − In the past few decades, the supramolecular self-assembly characteristics of d 8 platinum­(II) complexes with square-planar molecular geometry have attracted tremendous attention. − Such distinctive characteristics are associated with noncovalent Pt­(II)···Pt­(II) and π–π stacking interactions between adjacent complex molecules. − As the supramolecular self-assembly of platinum­(II) complexes leads to interesting spectral features with low-energy red to NIR emission enhancement, water-soluble alkynylplatinum­(II) complexes can serve as a biological probe as well as an imaging agent to investigate the activity of biological analytes and to stain organelles selectively in the low-energy red to NIR region, which coincides with the tissue-transparent spectral window. − Unfortunately, at present, a number of commercially available fluorescent dyes only exhibit blue to green fluorescence with small Stokes shifts and short fluorescence lifetimes. Because of the strong interference associated with autofluorescence from cells and various biological substrates in this optical window, confocal images are apt to suffer from false-positive signals which will affect the accuracy of medical diagnosis.…”