Enhancing redox functionality in dinuclear europium complexes

Abstract

Europium stands out amongst the lanthanoid elements because of its accessibility in the divalent state, in addition to the more common trivalent state. To explore europium-based redox chemistry in the presence of redox-active ligands, we have synthesised a series of dinuclear europium complexes with different redox-active bridging ligands containing oxygen and nitrogen donor atoms. Here, we report three new dinuclear europium complexes containing different redox-active bridging ligands: [{EuII(i)2(tpa)}2(μ-bpym)] (1), [{EuIII(i)2(tpa)}2(μ-bptz˙−)][I] (2), and [{EuIII(tpa)2}(μ-Br4cat)3] (3) (tpa = tris(2-pyridylmethyl)amine; bpym = 2,2′-bipyrimidine; bptz = 3,6-bis(2-pyridyl)-1,2,4,5-tetrazin..