(μ-1,4,7,10-Tetraoxacyclododecane)bis[(1,4,7,10-tetraoxacyclododecane)lithium] bis(perchlorate)

Abstract

12-Crown-4 ether (12C4) and LiClO4 combine to form the ionic title compound, [Li2(C8H16O4)3](ClO4)2, which is composed of discrete Li/12C4 cations and perchlorate anions. In the [Li2(12C4)3]2+ cation there are two peripheral 12C4 ligands, which each form four Li—O bonds with only one Li+ atom. Additionally there is a central 12C4 in which diagonal O atoms form one Li—O bond each with both Li+ atoms. Therefore each Li+ atom is pentacoordinated in a distorted square-pyramidal geometry, forming four longer bonds to the O atoms on the peripheral 12C4 and one shorter bond to an O atom of the central 12C4. The cation occupies a crystallographic inversion centre located at the center of the ring of the central 12C4 ligand. The Li+ atom lies above the cavity of the peripheral 12C4 by 0.815 (2) Å because it is too large to fit in the cavity.