title: Crystal structure of (E)-4-{2-[4-(all-yloxy)phen-yl]diazen-yl}benzoic acid.
abstract: The title compound, C16H14N2O3, has an E conformation about the azo-benzene [-N=N- = 1.2481 (16) Å] linkage. The benzene rings are almost coplanar [dihedral angle = 1.36 (7)°]. The O atoms of the carb-oxy-lic acid group are disordered over two sets of sites and were refined with an occupancy ratio of 0.5:0.5. The two disordered components of the carb-oxy-lic acid group make dihedral angles of 1.5 (14) and 3.8 (12)° with the benzene ring to which they are attached. In the crystal, mol-ecules are linked via pairs of O-H⋯O hydrogen bonds, forming inversion dimers. The dimers are connected via C-H⋯O hydrogen bonds, forming ribbons lying parallel to [120]. These ribbons are linked via C-H⋯π inter-actions, forming slabs parallel to (001).
authors.affiliation: University Malaysia Pahang, Faculty of Industrial Sciences and Technology, 26300 Gambang, Kuantan, Pahang, Malaysia.
authors.forename: Md Lutfor
authors.initials: ML
authors.lastname: Rahman
authors.affiliation: University Malaysia Pahang, Faculty of Industrial Sciences and Technology, 26300 Gambang, Kuantan, Pahang, Malaysia.
authors.forename: Mashitah
authors.initials: M
authors.lastname: Mohd Yusoff
authors.affiliation: University Malaysia Pahang, Faculty of Industrial Sciences and Technology, 26300 Gambang, Kuantan, Pahang, Malaysia.
authors.forename: Jamil
authors.initials: J
authors.lastname: Ismail
authors.affiliation: School of Chemical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
authors.forename: Huey Chong
authors.initials: HC
authors.lastname: Kwong
authors.affiliation: X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
authors.forename: Ching Kheng
authors.initials: CK
authors.lastname: Quah
keywords: azo­benzene; benzoic acid; crystal structure; liquid crystal; nematic phase