Coordination Compounds of Strontium: Syntheses, Characterizations, and Crystal Structures of [Sr(μ-ONc)2(HONc)4]2 and Sr5(μ4-O)(μ3-ONep)4(μ-ONep)4(HONep)(solv)4 (ONc = O2CCH2CMe3; Nep = CH2CMe3; solv = Tetrahydrofuran or 1-Methyl-Imidazole)

We have synthesized and characterized two novel Sr compounds: [Sr(μ-ONc)2(HONc)4]2 (1, ONc ˭ O2CCH2CMe3), and Sr5(μ−O)(μ3˭ONep)4(μ˭ONep)4(HONep)(solv)4 [ONep ˭ OCH2CMe3, solv = tetrahydrofuran (THF), 2a; 1-methyl-imidazole (Melm), 2b], that demonstrate increased solubility in comparison to the commercially available Sr precursors. The two metal centers of 1 share four unidentate bridging μ-ONc ligands and complete their octahedral geometry through coordination of four monodentate terminal HONc ligands. The structural arrangement of the central core of 2a and 2b are identical, wherein four octahedral Sr atoms are arranged in a square geometry around a μ4-O ligand. An additional seven-coordinated Sr atom sits directly atop the μ4-O to form a square-pyramidal arrangement of the Sr atoms, but the apical Sr-O distance is too long to be considered a bond. In solution, compound 1 is disrupted forming a monomer but 2a and 2b retain their structures.