The rigid C-1-bridged dilithiobis(cyclopentadienide) 4, prepared by means of a fulvene route, cannot attain the usual linear (LiCp)(2) structure because of the angular Cp-Li-Cp confinement. Consequently, a cyclotetrameric [Li-2(Cp-R-Cp)]4 supramolecular structure is observed of 4 tmeda by X-ray diffraction, the essential structural subunits of which are very well reproduced by quantum chemical calculations.