Redox isomerism in the lanthanide complex [(dpp-Bian)Yb(DME)(mu-Br)]2 (dpp-Bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene).

Ytterbium reacts with 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (1, dpp-Bian) in 1,2-dimethoxyethane (DME) to give complex (dpp-Bian)Yb(DME)(2) (2). Oxidation of 2 with an 0.5 mol equivalent of dibromostilbene affords dimeric compound [(dpp-Bian)Yb(DME)(mu-Br)](2) (3). Molecular structures of 2 and 3 were determined by single-crystal X-ray analysis. In complex 3 in a DME solution, a temperature-dependent reversible intramolecular electron transfer between the ligand and the metal takes place.