Geminal Charge-Assisted Tetrel Bonds in Bis-Pyridinium Methylene Salts

C(sp3) atoms are known to act as electrophilic sites in self assembly processes, and in all cases reported till now, they form only one interaction with nucleophiles; that is, they function as monodentate tetrel bond donors. This manuscript reports experimental (X-ray structural analysis) and theoretical evidence (DFT calculations), proving that the methylene carbon in bis-pyridinium methylene salts establishes two short and directional C(sp3)center dot center dot center dot anion interactions; that is, they function as bidentate tetrel bond donors