Benzene-1,2,4,5-tetrol

Abstract

The crystal structure of the title compound was determined at 120 K. It crystallizes in the triclinic space group P with four independent mol-ecules in the asymmetric unit. In the crystal, each symmetry-unique mol-ecule forms π-π stacks on itself, giving four unique π-π stacking inter-actions. Inter-molecular hydrogen bonding is observed between each pair of independent mol-ecules, where each hy-droxy group can act as a hydrogen-bond donor and acceptor.

Keywords: benzene-1,2,4,5-tetrol; covalent organic framework; crystal structure; hydrogen bonds; hydrox­yl.

Figure 1

The asymmetric unit of the title compound showing the atom labelling with 50% probability displacement ellipsoids. Unlabelled atoms are related to labelled atoms by the symmetry operations −x, −y + 2, −z for mol­ecule A, −x + 1, −y + 1, −z for mol­ecule B, −x + 1, −y, −z + 1 for mol­ecule C and −x + 2, −y + 1, −z + 1 for mol­ecule D.

Figure 2

(a) View of unit cell along the crystallographic a-axis. Dashed lines represent hydrogen bonding between mol­ecules. (14) rings are indicated with purple and green polygons; hydrogen bonds not lying on the indicated rings form the same class of ring with mol­ecules not rendered in this diagram. (b) View approximately along the (001) axis, showing how mol­ecules form π–π stacks. Some mol­ecules have been removed for clarity.