Discovery of species with adaptive aromaticity, being aromatic in both the lowest-lying singlet and triplet states (S0 and T1), is a significant challenge because cyclic conjugated complexes are commonly aromatic in one state only according to Hückel’s and Baird’s rules. On the other hand, the carbone ligands containing two lone pair electrons at the carbon(0) atom have attracted considerable attention from both theoretical and experimental chemists recently.
J. Phys. Org. Chem.
Journal of Physical Organic Chemistry