Supra-molecular architecture in a co-crystal of the N(7)-H tautomeric form of N (6)-benzoyl-adenine with adipic acid (1/0.5)

Abstract

The asymmetric unit of the title co-crystal, C12H9N5O·0.5C6H10O4, consists of one mol-ecule of N (6)-benzoyl-adenine (BA) and one half-mol-ecule of adipic acid (AA), the other half being generated by inversion symmetry. The dihedral angle between the adenine and phenyl ring planes is 26.71 (7)°. The N (6)-benzoyl-adenine mol-ecule crystallizes in the N(7)-H tautomeric form with three non-protonated N atoms. This tautomeric form is stabilized by intra-molecular N-H⋯O hydrogen bonding between the carbonyl (C=O) group and the N(7)-H hydrogen atom on the Hoogsteen face of the purine ring, forming an S(7) ring motif. The two carboxyl groups of adipic acid inter-act with the Watson-Crick face of the BA mol-ecules through O-H⋯N and N-H⋯O hydrogen bonds, generating an R 2 (2)(8) ring motif. The latter units are linked by N-H⋯N hydrogen bonds, forming layers parallel to (10-5). A weak C-H⋯O hydrogen bond is also present, linking adipic acid mol-ecules in neighbouring layers, enclosing R (2) 2(10) ring motifs and forming a three-dimensional structure. C=O⋯π and C-H⋯π inter-actions are also present in the structure.

Keywords: N6-benzoyl­adenine; adipic acid; co-crystal; crystal structure; hydrogen bond; supra­molecular sheet; π–π stacking.

Figure 1

A Mercury (Macrae et al., 2008 ▸) view of the title compound (I), showing the atom-numbering scheme. Disordered oxygen atoms are omitted for clarity. H atoms not involved in hydrogen bonding have been omitted for clarity. Unlabelled atoms are related by the symmetry operation 1 − x, 1 − y, −z.

Figure 2

A view of the sheet-like supra­molecular architecture generated via C19—H19B⋯O3A hydrogen bonds (black dotted lines). Phenyl rings are indicated as yellow balls. H atoms not involved in hydrogen bonding have been omitted for clarity. Symmetry codes are as given in Table 1 ▸.

Figure 3

(a) A view of the C—H⋯π inter­action in compound (I). Cg3 is the centroid of the phenyl ring of the BA mol­ecule (symmetry code: x, −1 + y, z). (b) A view of the C=O⋯π inter­action. Cg2 is the centroid of the pyrimidine ring of the BA mol­ecule (symmetry code: 1 − x,  + y,  − z).