Revisiting sp2 Dilithio Methandiides: From Geometric Curiosity to Simple Bonding Description

The reported tetracoordinate dilithio methandiide complex from Liddle and co‐workers (1) is investigated from a coordination chemistry perspective, to probe the origin of its intriguing geometry. Through the application of a variety of computational techniques, non‐covalent (steric, electrostatic) interactions are found to be dominant. Further, we arrive at a bonding description which emphasizes the tricoordinate sp2‐hybridized nature of the central methandiide carbon, differing somewhat from the original proposal. Thus, 1 is distinct from other dilithio methandiides since it contains only one C−Li σ‐bond, and is found to be comparable to a simple aryllithium compound, phenyllithium. The intriguing tetracoordinate geometry of a dilithio methandiide complex is probed from a coordination chemistry perspective, demonstrating the sp2‐hybridized nature of the methandiide carbon and the other (non‐covalent) interactions responsible for its planarity.