Dimers of thf-solvated lithium anilide and lithium pentafluoroanilide: basic building blocks of lithium amide ladder structures

Representing the elementary constituents in the dis-assembling process of lithium amide ladder arrangements, the tetrasolvated dimers [C6H5H(H)Li·2thf]2 and [C6F5N(H)Li·2thf]2 are isolated and cryo-crystallographically characterised, which, based on the unexpected geometries in the solid-state structures, lead to the unaccustomed classification of nitrogen tending to sp2 hybridisation in the planar (LiN)2 four-membered rings.