CRYSTAL-STRUCTURE OF N-CYANO-N-PROP-2-YNYL-ANILINE AND STRUCTURAL DATA ON UIVALENT-TO-C-H-CENTER-DOT-CENTER-DOT-CENTER-DOT-N HYDROGEN-BONDS

In the crystal structure of N-cyano-N-prop-2-ynyl-aniline, the propyny l group does nor form the expected dominant intermolecular interaction , but only a very long and distorted contact to the cyano acceptor. De spite the long H ... N separation of 2.75 Angstrom, the infrared absor ption spectrum indicates weakly hydrogen bonding nature of this contac t. A short database analysis on hydrogen bonds from terminal alkynes t o N accepters is also performed, showing that the hydrogen bond in the title compound is the longest of this kind observed as yet. (C) 1998 Elsevier Science B.V. All rights reserved.