Mutual influence between conventional and unconventional lithium bonds.

The interplay between conventional and unconventional lithium bonds interactions in NCLi⋯NCLi⋯XCCX and CNLi⋯CNLi⋯XCCX (X=H, F, Cl, Br, OH, CH3, and OCH3) complexes is studied by ab initio calculations. Cooperative effects are observed when Li⋯N(C) and Li⋯π bonds coexist in the same complex. These effects are analyzed in terms of geometric, energetic and electron charge density properties of the complexes.