addenda and errata
Free
In the paper by Durruthy, Pomes, Fajardo & Dago [Acta Cryst. (1993). C49, 558-559], an NN hydrogen bond was incorrectly described as intermolecular. After refinement of the structural model, a weak intermolecular hydrogen bond between a CN group of one molecule and an NH group of an ajacent one was established with NN 3.113 (3), NH 2.389 (3) Å and N–HN 142.0 (1)°. The molecule crystallizes in the E configuration.