A rare earth alloy as a synthetic reagent: contrasting homometallic rare earth and heterobimetallic outcomes

摘要

Reaction of LaNi5 with 2,2-dipyridylamine (HNpy(2)) at 170 degrees C under vacuum gave crystals of dimeric [La(Npy(2))(3)](2) as a previously unknown eight-coordinate isomer (1a) (two mu-eta(2):eta(2) and two terminal chelating (N-amide,N-py) Npy(2) ligands), which reverts to the known ten coordinate isomer (1b) on recrystallisation from THF/PhMe, thereby establishing linkage isomerism of a [Ln(Npy(2))(3)](2) complex for the first time. Reaction of 8-hydroxyquinoline (HOQ) with excess LaNi5 alloy at 190 degrees C resulted in extraction of both metals and the formation of heterobimetallic [Ni2La(OQ)(7)] (2). The trinuclear complex has two terminal, fac-octahedral nickel(II) sites, each bound to three chelating 8-quinolinolate anions which bridge through the oxygen atoms to the lanthanum(III) centre. The eight-coordinate lanthanum environment is completed by a chelating OQ ligand.