X-Ray crystal structure of [{o-C6H4(CHPh)2}{Li(tmeda)}2](tmedaMe2NCH2CH2NMe2). Unsymmetrical lithium bridging and (E,E)-conformation of the phenyl groups

Abstract

The lithium atoms in the title compound are shown by X-ray analysis to prefer quite different locations, in contrast to the symmetrical double bridging exhibited by other 1,4-dilithium compounds, but in agreement with model MNDO calculations; furthermore, the (E,E) conformation of the two phenyl groups differs from the (E,Z) conformation reported in methyltetrahydrofuran solution.