A triclinic polymorph of octa-tert-butoxy-tetralithiumtetrasodium

The title compound, tetra-mu(3)-tert-butoxy-tetra-mu(4)-tert-butoxytetralithiumtetrasodium, [Li4Na4 (C4H9O)(8)], has been obtained in a second, triclinic, modification, with three crystallographically independent molecules in the asymmetric unit. All three molecules, as well as the two independent molecules of a previously reported monoclinic polymorph, have essentially the same structure, in which the tert-butoxy ligands are either triply or quadruply bridging, Li+ cations have trigonal pyramidal coordination, and Na+ cations have irregular fourfold coordination. The molecules have no crystallographic symmetry, but approximate to (4) over bar 2m (D-2d) symmetry.