Mixed ligand complexes of AEE hexafluoroacetylacetonates with diglyme: Synthesis, crystal structure and thermal behavior

The novel mixed ligand complexes [Ca(hfa)2(diglyme)(H2O)] (I), [Sr(hfa)2(diglyme)(H2O)] (II) and [Ba(hfa)2(diglyme)2] (III) (Hhfa = 1,1,1,5,5,5-hexafluoropentane-2,4-dione, diglyme = 2,5,8-trioxanonane) were synthesized by the reactions of the alkaline earth element (AEE) carbonates in n-hexane with a mixture of Hhfa and diglyme, and they were characterized by elemental analysis, 1H and 13C NMR, and FTIR spectroscopy. The crystal structures of I–III, consisting of mononuclear isolated molecules, have been determined. The thermal behavior and composition of the vapor phase have been studied for I–III by thermal analysis at low pressure and mass spectrometry using a Knudsen cell. The stability of the mixed ligand complexes [M(hfa)2(diglyme)n] to the removal of diglyme molecules under heating decreases in the row I > II ≈ III, and only I evaporates as the mixed ligand complex after water removal.

Graphical abstractThe synthesis, crystal structures and thermal behavior of the novel mixed ligand complexes [Ca(hfa)2(diglyme)(H2O)] (I), [Sr(hfa)2(diglyme)(H2O)] (II), [Ba(hfa)2(diglyme)2] and (III) (Hhfa – 1,1,1,5,5,5-hexafluoropentane-2,4-dione, diglyme – 2,5,8-trioxa-nonane) are described.Figure optionsDownload full-size imageDownload as PowerPoint slide