Unique Type II Halogen···Halogen Interactions in Pentafluorophenyl-Appended 2,2′-Bithiazoles

Herein, we report the design and synthesis of 2,2′-bithiazole derivatives with efficient intermolecular halogen interactions. The single crystal X-ray diffraction studies revealed unique type-II halogen interactions in these derivatives. The shortest type-II F···F interactions within the distance of 2.67 Å, at an angle of 89.1° and 174.2°, was observed for the first time. The Gaussian calculations were performed to further establish predominant F···F interactions.