were cleanly obtained in spectroscopically quantitative yields, as in the case of their symmetrical congeners Li2 [3] and Li2 [4]. Both showed the same SSIP character in THF solution at room temperature and were fully characterised by NMR spectroscopy and high-resolution mass spectrometry (Figures ). Likely as a result of their reduced symmetry (time-averaged D2d), the homobimetallic dilithium salts remained fully soluble at 10 -2 M concentration in THF for several months at room temperature. Interestingly, both 5 and 6 displayed a distinct chemical shift difference of 0.06 ppm for their respective wingtip protons H 2 and H 5 , indicative of a different polarisation of the two fivemembered rings of the pentalenide core.