Cooperative CC–H ⋯ CC–H interactions: crystal structure of DL -prop-2-ynylglycine and database study of terminal alkynes

In the crystal structure of DL-prop-2-ynylglycine, the alkyne groups form a zigzag pattern with intermolecular H ⋯ C distances of 2.54 Å, which is suggestive of cooperative C–H ⋯ CC (C–H ⋯π) hydrogen bonding; alkyne–alkyne contacts with similar geometries are found in a number of other crystal structures.