2,2â²-Biquinoline is an organic compound with the formula (C<sub>9</sub>H<sub>6</sub>N)<sub>2</sub>. It is one of several biquinolines. It is prepared by reductive coupling of 2-chloroquinoline. It is a colorimetric indicator for organolithium compounds.
2,2â²-Biquinoline is a bidentate ligand. Unlike the related complexes of 2,2â²-bipyridine, the metal does not typically occupy the plane of the biquinoline.