4-Fluoro-1H-indazole (also known as 4-Fluoroindazole), CAS number 341-23-1, a fluorinated indazole heterocyclic aromatic compound and a powerful chromophore unit, consists of a fluoride substituent at 4-position with the pyrazole fused to a benzene ring. 4-Fluoro-1H-indazole can readily be further functionalized via nucleophilic aromatic substitution reactions.
Pyrazoles and indazoles have been extensively used pharmaceutical industry with a variety of biological activities. Indazole is a highly conjugated molecule which expands its applications to dye-sensitized solar cells (DSSCs). Owing to the pyrazole moiety, 4-fluoro-1H-indazole can coordinate to metal center (such as Ir, Ln and Eu) to form either heteroleptic or homoleptic triplet photosensitizers that have an efficient ligand to metal energy transfer process. The fluorine group in the molecule is electron deficient and can be used to tune the energy gap of the molecule/complex. This fluorinated indazole enable the intermolecular interaction including π−π stacking and H−F hydrogen/halogen bonding.