Emissive cyanide-bridged bimetallic compounds as building blocks for polymeric antennae

Dalton Trans. 2013 Dec 28;42(48):16723-32. doi: 10.1039/c3dt51164b. Epub 2013 Sep 27.

Abstract

A series of cyanide-bridged bimetallic compounds of the general formula [Ru(L)(bpy)(μ-NC)(M)](2-/-/2+) (L = tpy, 2,2'-6',2''-terpyridine, or tpm, tris(1-pyrazolyl)methane, bpy = 2,2'-bipyridine, M = Ru(II)(CN)5, Os(III)(CN)5, Os(II)(CN)5, Ru(II)(py)4(CN), py = pyridine) have been synthesized and fully characterized. Most of them present MLCT emission (λ = 690-730 nm, Φ = 10(-3)-10(-4)) and their photophysical properties resemble the ones of the respective mononuclear Ru(L)(bpy) species. The exception is when M is Os(III)(CN)5, where an intramolecular electron transfer quenching mechanism is proposed. The conditions that should be met for avoiding the reductive or oxidative quenching of the excited state are also discussed.