Studies of the packing of cocrystals of alkynoic acids with amine and pyridine acceptors

We have been successful in generating and determining the crystal structure of a new type of carboxylic acid cocrystal with a pyridine-based acceptor. In order to extend our work on the solid-state reactivity and crystal engineering of pyridine- or amine : carboxylic acid cocrystals, it seemed worthwhile to attempt to generate two-dimensional layer structures with van der Waals spacings between the layers. We decided to use an "extended" planar acceptor, viz., trans-1,2-bis(4-pyridyl)ethylene 1, with the expectation that the extended conjugation would promote the formation of planar arrays when cocrystals were synthesized with carboxylic acids.


We have synthesized a cocrystal with 4-pentynoic acid 2, and have just completed an X-ray structure determination. As can be seen, planar arrays indeed are formed!




Is this part of a bigger picture? We think so....when we synthesized cocrystals of 1 and 2-butynoic acid, CHCCOOH, it happened again:




Stay tuned for further developments.

This material is based upon work supported by the National Science Foundation under Grant No. DMR-0089257. Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation (NSF).


Send content and research comments to Bruce Foxman ( foxman1@brandeis.edu)

Bruce Foxman ( foxman1@brandeis.edu)