Triethyl-ammonium 1,1'-binaphthyl-2,2'-diyl phosphate.

In the crystal structure of the title compound, C(6)H(16)N(+)·C(20)H(12)O(4)P(-), an N-H⋯O inter-action links the cation to the anion. The N atom in the triethyl-ammonium cation exhibits a trigonal-bipyramidal coordination geometry and forms an N-H⋯O inter-action with one phosphate O atom of the 1,1'-binaphthyl-2,2'-diyl phosphate ligand. A bifurcated C-H⋯O inter-action with the other phosphate O atom links molecules along the a axis. The dihedral angle between the two naphthyl ring systems is 58.92†(3)°. The refined Flack parameter value of 0.50†(10) indicates inversion twinning.