title: 4,4'-Bipyridine-pyroglutamic acid (1/2).
abstract: In the title co-crystal, C(10)H(8)N(2)·2C(5)H(7)NO(3), the 4,4'-bipyridine mol-ecule [dihedral angle between the pyridine rings = 36.33 (11)°] accepts O-H⋯N hydrogen bonds from the two pyroglutamic (pga) acid mol-ecules. The pga mol-ecules at each end of the trimeric aggregate self-associate via centrosymmetric eight-membered amide {⋯HNCO}(2) synthons, so that the crystal structure comprises one-dimensional supra-molecular chains propagating in [13]. C-H⋯O and π-π stacking inter-actions [centroid-centroid separation = 3.590 (2) Å] consolidate the structure.
authors.forename: Hadi D
authors.initials: HD
authors.lastname: Arman
authors.forename: Trupta
authors.initials: T
authors.lastname: Kaulgud
authors.forename: Edward R T
authors.initials: ER
authors.lastname: Tiekink