E0006

Hexagonal Tiling of Tetrachloro-dicyanobenzene Isomers. Doyle Britton, Dept of Chemistry, Univ. of Minnesota, Minneapolis, MN 55455-0431

Seven 1/1 crystal complexes of the various isomers of tetrachlorodicyanobenzene, TDB, and hexamethylbenzene, HMB, have been prepared. One complex of o-TDB and HMB, two polymorphic complexes of m-TDB and HMB, and four polymorphic complexes of p-TDB and HMB have been found. All of the complexes involve layers of two-dimensional arrays, and in six of the complexes the layers are homogeneous, alternate layers being entirely TDB or entirely HMB. The layers can be described in terms of an hexagonal tiling and in five of the homogeneous layers the TDB are ordered so that one CN and two Cl come together at each corner of the tiles. This can be thought of as the Lewis acid, CN, in a bifurcated interaction with two Lewis acids, Cl.