A new triclinic polymorph of 4-n-hexyloxybenzoic acid

The title new triclinic polymorph of 4-n-hexyloxybenzoic acid, C13H18O3, crystallizes with six independent molecules in the asymmetric unit. Four of these have the hydroxyl group arranged cis to the methylene group attached to the ether O atom, whereas in two molecules the carbonyl group is cis to the methylene group at the ether O atom. All molecules form hydrogen-bonded dimers through the carboxylic acid functionalities. The cell parameters for what appears to be the title polymorph had been originally inaccurately determined as monoclinic [a = 14.5 angstrom, b = 33.0 angstrom, c = 8.0 angstrom, alpha = 90.0 degrees, beta = 93.0 degrees and gamma = 90.0 degrees; Bryan (1960). J. Chem. Soc. pp. 2517-2519]; no space group was given and no atomic coordinates were available. The other polymorph known for the title compound is a Z' = 1 phase crystallizing in P2(1)/c [Bryan et al. (1980). Mol. Cryst. Liq. Cryst. 62, 311-326].