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.

A 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 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.