title: 2-[(E)-(5-tert-Butyl-2-hydroxy-phen-yl)-diazen-yl]benzoic acid.
abstract: The title compound, C(17)H(18)N(2)O(3), is approximately planar, owing in part to an intra-molecular bifurcated O-H⋯(N,O) hydrogen bond; the dihedral angle between the two aromatic rings is 23.86 (9)°. In the crystal struture, centrosymmetrically related mol-ecules associate into dimers via the eight-membered carboxyl-ate {⋯H-O-C=O}(2) synthon.
authors.forename: Tushar S
authors.initials: TS
authors.lastname: Basu Baul
authors.forename: Anup
authors.initials: A
authors.lastname: Paul
authors.forename: Hadi D
authors.initials: HD
authors.lastname: Arman
authors.forename: Edward R T
authors.initials: ER
authors.lastname: Tiekink