Synthesis and characterization of the heavy alkaline earth aryloxide congeners

A series of the heavier alkaline earth (AE) aryloxides were synthesized from the reaction of the metal (AE°) or the ‘AE(ONep)2’ (ONep = neo-pentoxide) precursor with a series of 2,6-di-alkyl phenols (alkyl = methyl (H-DMP), iso-propyl (H-DIP), tert-butyl (H-DBP)). These products were crystallographically characterized as: [(py)3(DMP)Sr(μ-DMP)]2·py (1), [Sr(DIP)2(py)4] (2), [Sr(DBP)2(py)3] (3), [(py)3Ba(μ-DMP)3Ba(DMP)(py)2][Ba[(μ-DMP)3Ba(py)3]2] (4), and [Ba(OAr)2(py)n] where OAr = DIP, n = 4 (5), DBP, n = 3 (6). In some instances AE-oxide alkoxides were crystallographically identified and have been preliminarily identified by single crystal X-ray diffraction. NMR data showed a single set of resonances for 1–6, which argues for monomeric species to exist in solution.

Graphical abstractA series of the heavier alkaline earth (AE) aryloxides were synthesized from the reaction of the AE° with a series of 2,6-di-alkyl phenols in pyridine at reflux conditions. All products were solvated, with the majority adopting mononuclear species but dinuclear (shown) and trinuclear were observed.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Sr and Ba aryloxides synthesized from reaction of metal and alcohol at reflux pyridine temperatures. ► Sr(OAr)2: [(py)3(DMP)Sr(μ-DMP)]2·py, [Sr(DIP)2(py)4], [Sr(DBP)2(py)3]. ► Ba(OAr)2: [(py)5Ba2(μ-DMP)3(DMP)][Ba3(μ-DMP)6(py)6], [Ba(OAr)2(py)n] OAr = DIP; DBP.