Directional preferences of ether O-atoms towards alkali and alkaline earth cations

Abstract

An analysis of the environments of alkali and alkaline earth cations complexed to ethers has been made with the Cambridge Structural Database. The cations invariably lie close to the bisecting plane through the O-atoms. The larger cations show an apparent preference to approach the ether group along a tetrahedral lone pair direction, whereas Li⁺ cations tend to be found along the C-O-C bisector, i.e., along the trigonal lone pair direction. These observations are discussed in relation to recent theoretical and experimental findings.