4,4′-Bis(trifluoromethyl)-2,2′-bipyridine (CAS number 142946-79-0), also known as 4,4'-(CF3)2bpy, is a 2,2'-bipyridine derivative that has two anchoring trifluoromethyl groups. 2,2'-bipyridine is a popular ligand, as the nitrogen atoms and the metal center form a stable 5-membered ring. Homoleptic rare earth metal (terbium and dysprosium) complexes with 4,4′-bis(trifluoromethyl)-2,2′-bipyridine show quantum yield up to 0.9% and high relaxation rate of 99.5 Hz in 19F NMR (B = 5.87 T at 298 K). It exhibits a great potential to use in 19F MRI/optical imaging probes.
The trifluoromethyl anchoring groups in 4,4′-bis(trifluoromethyl)-2,2′-bipyridine improve the photoconversion efficiency (up to 34%) in dye-sensitive solar cells (DSSCs). The enhancement is owing to the stabilization of the highest occupied molecular orbital (HOMO) introduced by the fluorinated building blocks.