Group IIA metal β-diketonate complexes; the crystal structures of [Sr3(tmhd)6(Htmhd)]·C6H5Me·C5H12 and [Ba4(tmhd)8](Htmhd = 2,2,6,6-tetramethylheptane-3,5-dione)

Abstract

Hydrocarbon-soluble Group IIA metal ethoxides [{M(OEt)₂(EtOH)₄}_n](M = Sr or Ba) react with the β-diketonate 2,2,6,6-tetramethylheptane-3,5-dionate (Htmhd) to yield the volatile complexes [Sr₃(tmhd)₆(Htmhd)] and [Ba₄(tmhd)₈] in excellent yield. These materials have been studied by classical spectroscopic techniques, differential scanning calorimetry and thermogravimetric analysis. They have also been characterised by single-crystal X-ray diffraction at 150 K, and shown to exist as a trimer and tetramer respectively, the former also incorporating a neutral Htmhd ligand.