Quinolin-6-ol at 100 K.

The title compound, C(9)H(7)NO, has two symmetry-independent molecules in the asymmetric unit, which have different conformations of the hydroxy group with respect to the quinoline ring. One of the molecules adopts a cis conformation, while the other shows a trans conformation. Each type of independent molecule links into a separate infinite O-H...N hydrogen-bonded chain with the graph-set notation C(7). These chains are perpendicular in the unit cell, one extended in the a-axis direction and the other in the b-axis direction. There is also a weak C-H...O hydrogen bond with graph-set notation D(2), which runs in the c-axis direction and joins the two separate O-H...N chains. The significance of this study lies in the comparison drawn between the experimental and calculated data of the crystal structure of the title compound and the data of several other derivatives possessing the hydroxy group or the quinoline ring. The correlation between the IR spectrum of this compound and the hydrogen-bond energy is also discussed.