Nature of Short Li...H-C Contact Interactions in Organolithium Compounds and Its Implication.

摘要

Our study shows that short Li ... H distances of intermolecular Li ... H-C contacts occur when the carbon atom bears at least one Li atom. Such an Li ... H-C contact interaction is strongly stabilizing, and the associated interaction energy is nearly half the binding energy of an isolated LiH. This finding provides a natural explanation for the observation that solid alkyllithium exists as oligomeric units containing lithium atom clusters, because formation of the lithium atom clusters leads to a large number of strongly stabilizing intermolecular Li ... H-C contacts involving the Li-bearing carbon atoms. The present work shows that a C-H bond can be lengthened significantly when it makes several Li ... H-C contacts close to right-angle arrangements.