Theoretical characters and nature of the intermolecular lithium bonded interactions B⋯LiCN/LiNC (B = pyridine, furan and thiophene)

The characters (geometries, interaction energies, and electronic properties, etc.) of the intermolecular interactions between heteroaromatic rings (C5H5N, C4H4O and C4H4S) and Lewis acids (LiCN, LiNC) have been studied at the MP2/aug-cc-pVTZ level. Two types of interactions are observed: N/O⋯Li (type I) and π⋯Li (type II) bonded interactions. The calculated interaction energies show that type I structures are more stable. The nature of the intermolecular interactions has been also investigated by natural bond orbital (NBO), atoms in molecules (AIMs) and symmetry adapted perturbation theory (SAPT) methods, and the results demonstrate that the type I interactions are predominantly electrostatic in nature, while the induction forces dominate the type II interactions.