[2‐(1H‐Inden‐3‐yl)­ethyl]­di­phenyl­phos­phine–borane

The title compound, C₂₃H₂₄BP, crystallizes in the centrosymmetric space group P2₁/c, with one mol­ecule in the asymmetric unit. The indene moiety is essentially planar. The P—B bond length is 1.923 (3) Å, which is within the expected range.