Multinuclear rare-earth metal complexes supported by chalcogen-based 1,2,3-triazole

Abstract

The reaction of MCp3 (M=Y, Nd, Sm, Gd) with the 4,5-bis(diphenylselenophosphoranyl)-1,2,3-triazole (LH) (1) in the presence of stoichiometric amounts of H2O afforded the trinuclear rare-earth metal complexes [(MCp)3(μ3-O)L4] [M=Y (3), Nd (4), Sm (5), Gd (4)]. The unforeseen formation of these multimetallic systems stems from the protonolysis reactions of the intermediate dicyclopentadienyl rare-earth complexes MCp2L with H2O. This was confirmed by the transformation of YCp2L (2) to (YCp)3(μ3-O)L4 (3) under controlled conditions. X-ray diffraction studies reveal that 3–6 possess a trinuclear [M3(μ3-O)] core with M–Se contacts featuring M⋯M interactions. The magnitude of the M⋯M separations is controlled by the constrictions imposed on the planar [M3(μ3-O)] core by the surrounding M2ON2 and M2ON ring systems. DFT calculations were performed on 3 which was used as a model compound for the heavier rare-earth metals providing insight into the nature of the Y–Se and Y–N contacts around the M3(μ3-O) core.