The Preparation and Characterization of Novel Organic Solids

1. The Preparation and Characterization of Novel Organic Solids William H. Ojala, Department of Chemistry, University of St. Thomas St. Paul, MN 55105-1079 Bridge-Flipped Isomers: Our designation for pairs of chemically different molecules with the same numbers and kinds of atoms (isomeric molecules) in which two major parts of the molecule are joined by a bridge of atoms, the exchange of atoms between positions in the bridge relating one isomer to the other We aim to prepare new materials by co-crystallizing bridge-flipped isomeric compounds such as benzylideneanilines and phenylhydrazones; this is facilitated by the isomers’ similarity in size and shape. For co-crystallization to succeed, the isomers should have the same molecular packing arrangements in their respective crystals. We have now identified our first pair of isostructural isomers (at left and below) by single-crystal X-ray diffraction. Our next goal will be to prepare a new solid material by growing crystals containing both bridge-flipped isomers.