Cyclometalated complexes of ruthenium. 3. Spectral, electrochemical and two-dimensional proton NMR of [Ru(bpy)2(cyclometalating ligand)]+

Sticking and patching: tuning and anchoring cyclometallated ruthenium(ii) complexes

“…The tris-chelate [Ru(bpy) 2 (ppy)] + (bpy = 2,2'-bipyridine, Hppy = 2-phenylpyridine) is an archetype cyclometallated analogue 1,2 of [Ru(bpy) 3 ] 2+ . Over the last few years, there has been a renewed interest in cyclometallated ruthenium(II) complexes in the context of their application in n-type dye-sensitized solar cells (DSCs).…”

“…7 Replacing thiocyanate by an anionic C^N ligand provides a means of tuning the HOMO-LUMO properties of the dyes. The HOMO of a [Ru(N^N) 2 (C^N)] + complex is localized on the metal and C^N ligand, 8 and therefore the energy of the HOMO can be altered by introducing electron-withdrawing or electrondonating substituents into the phenyl ring. This strategy has been successfully applied to tune orbital energies and emission properties of cyclometallated iridium(III) complexes in organic light-emitting diodes (OLEDs) and light-emitting electrochemical cells (LECs).…”

“…This strategy has been successfully applied to tune orbital energies and emission properties of cyclometallated iridium(III) complexes in organic light-emitting diodes (OLEDs) and light-emitting electrochemical cells (LECs). 9 An advantage of [Ru(N^N) 2 (C^N)] + dyes in DSCs is the significant red-shift in their absorption spectra yielding improved photoresponse. The potential for enhanced photon-to-current conversion efficiencies has prompted active exploration of cyclometallated ruthenium(II) sensitizers for n-type DSCs.…”

“…The potential for enhanced photon-to-current conversion efficiencies has prompted active exploration of cyclometallated ruthenium(II) sensitizers for n-type DSCs. 8,10,11 The effects of combining [Ru(N^N) 2 (C^N)] + sensitizers with the cobalt-based redox shuttle [Co(dmbpy) 3 ] 3+/2+ (dmbpy = 4,4'-dimethyl-2,2'-bipyridine) have also recently been reported. 12 In [Ru(N^N) 2 (C^N)] + dyes for n-type DSCs, the cyclometallating domain constitutes the ancillary ligand.…”

“…8,10,11 The effects of combining [Ru(N^N) 2 (C^N)] + sensitizers with the cobalt-based redox shuttle [Co(dmbpy) 3 ] 3+/2+ (dmbpy = 4,4'-dimethyl-2,2'-bipyridine) have also recently been reported. 12 In [Ru(N^N) 2 (C^N)] + dyes for n-type DSCs, the cyclometallating domain constitutes the ancillary ligand. However, the localization of the HOMO on the C^N ligand and ruthenium means that [Ru(N^N) 2 (C^N)] + complexes are of potential interest as sensitizers in either p-type or tandem DSCs.…”