Crystal structure of bis-[tetra-kis-(tetra-hydro-furan-κ O )lithium] bis[μ-2,2',2''-methanetriyltris(4,6-di- tert -butylphenolato)-κ 4 O , O ': O ', O '']-dimagnesiate.

The title ion-association metal complex, [Li(C4H8O)4]2[Mg2(C43H61O3)2], has been synthesized from the tridentate phenolic ligand tris­(3,5-di-tert-butyl-2-hy­droxy­phen­yl)methane in tetra­hydro­furan (THF). The aryl­oxo magnesiate complex anion is binuclear with each Mg2O4 complex unit inversion-related and bridged through the two tridentate chelating phenolate O-donors of the ligand. The complex centres have a distorted tetra­hedral stereochemistry [Mg—O range 1.8796 (17)–2.0005 (16) A] and an Mg⋯Mg separation of 2.9430 (14) A]. The LiO4 coodination sphere of the cation comprises four THF O-donor atoms and has a slightly distorted tetra­hedral conformation [Li—O range 1.899 (5)– 1.953 (5) A]. In the crystal, a number of stabilizing intra-anion C—H⋯O hydrogen-bonding inter­actions are present but no inter-species associations are found.