Herringbone array of hydrogen-bonded ribbons in 2-ethoxybenzamide from high-resolution X-ray powder diffraction

In 2-ethoxybenzamide, C9H11NO2, the amide substituents are linked into centrosymmetric head-to-head hydrogen-bonded dimers. Additional hydrogen bonds between adjacent dimers give rise to ribbon-like packing motifs, which extend along the c axis and possess a third dimension caused by twisting of the 2-ethoxyphenyl substituent with respect to the hydrogen-bonded amide groups. The ribbons are arranged in a T-shaped herringbone pattern and cohesion between them is achieved by van der Waals forces.