A second polymorph of bis­(triphenyl-λ⁵-phosphanyl­idene)ammonium chloride–boric acid adduct

The title crystal structure is a new triclinic polymorph of [(Ph₃P)₂N]Cl·(B(OH)₃) or C₃₆H₃₀NP₂⁺·Cl⁻·BH₃O₃. The crystal structure of the ortho­rhom­bic polymorph was reported by [Andrews et al. (1983). Acta Cryst. C39, 880–882]. In the crystal, the [(Ph₃P)₂N]⁺ cations have no significant contacts to the chloride ions nor to the boric acid mol­ecules. This is indicated by the P—N—P angle of 137.28 (8)°, which is in the expected range for a free [(Ph₃P)₂N]⁺ cation. The boric acid mol­ecules form inversion dimers via pairs of O—H...O hydrogen bonds, and each boric acid mol­ecule forms two additional O—H...Cl hydrogen bonds to one chloride anion. These entities fill channels, created by the [(Ph₃P)₂N]⁺ cations, along the c-axis direction.