(3R,4S)-3-Methyl-4-phenyl-2-[(R)-1-phenyl­eth­yl]-3,4-di­hydro­isoquinolin-2-ium tetra­fluorido­borate

The title salt, C₂₄H₂₄N⁺·BF₄⁻, is one of two possible dias­tereoisomers having a different configuration of the asymmetric centre in the α-phenyl­ethyl substituent, whose absolute configuration was established to be R. The two phenyl substituents of the cation have a cofacial orientation, albeit with a long centroid–centroid separation of 4.129 (3) Å. The crystal structure exhibits numerous C—H...F contacts between counter-ions, with the tetra­fluorido­borate anion surrounded by five iminium cations.