title: 1,1'-Binaphthalene-2,2'-diyl hydrogen phosphate.
abstract: The title compound, racemic bnppa, C(20)H(13)O(4)P, crystallizes with four mol-ecules in the asymmetric unit. Two independent centrosymmetric O-H⋯O hydrogen-bonded tetra-mers, each involving two of the symmetry-independent mol-ecules in the asymmetric unit generate the packing motif in the crystal structure. The hydro-phobic parts of the tetra-mers connect to their neighbours via C-H⋯π and π-π inter-actions [3.899 (2), 3.895 (2) and 3.803 (2) Å within the symmetric unit, 3.851 (2), 4.000 (2), 3.988 (2) and 3.905 (2) Å across centres of symmetry].
authors.forename: Susanta K
authors.initials: SK
authors.lastname: Nayak
authors.forename: S
authors.initials: S
authors.lastname: Chandrasekhar
authors.forename: T N Guru
authors.initials: TN
authors.lastname: Row