Expanding the Series of [RE2Ca(OQ)8] Structures: New Heterobimetallic Rare Earth/Alkaline Earth 8‐Quinolinolate Complexes

Abstract

AbstractAbstract. A series of heterobimetallic complexes [RE2Ca(OQ)8]·nHOQ(RE = Sm, Gd, Tb, Ho, Tm, Yb, Lu, Y, Sc) and the isostructural [Gd2Mg(OQ)8] were synthesised and structurally characterised. They were mainly obtained after direct reactions of the elemental rare earth metals with calcium metal in the presence of 8‐hydroxyquinoline (HOQ) and a 1, 3, 5‐tri‐tert‐butyl‐benzene (tBuB) flux, and some complexes were synthesised by pseudo solid‐state rearrangement reactions between powdered RE(OQ)3 and AE(OQ)2 (AE = Mg, Ca) in a 1, 2, 4, 5‐tetramethylbenzene (TMB) flux, at elevated temperatures. The linear trinuclear [RE2Ca(OQ)8] moieties show a six‐coordinate central calcium atom flanked by two eight‐coordinate rare earth atoms surrounded by six chelating‐bridging OQ and two terminal chelating OQ ligands. The structurally novel [Sc2Ca(OQ)8] has a bent Sc‐Ca‐Sc backbone and exhibits an eight‐coordinate central calcium and two seven‐coordinate scandium ions.