“…[2,12,13] Interestingly, planar pentacoordinate carbon atoms are often found in strained molecular clusters and solids, and they have been an active niche for theoretical predictions. [14][15][16][17][18][19][20][21][22][23][24] The search for pentacoordinate C atoms in organic molecules started in 1919 by Staudinger, [25] until, in 1999, the first such species having a strained anthracene backbone was prepared and characterized by X-ray diffraction. [1,3] Subsequently, such hypercoordinate carbon centers have been successfully prepared using ligands with various degrees of rigidity.…”