COMPLEXATION-MEDIATED CRYSTALLIZATION

Crown ether complexation solubilizes organic and inorganic salts in nonpolar media. Induction of crystallization from such solutions can result in crystallization of the free salt rather than the complex. This affords the opportunity to examine solvent effects on the crystallization of salts and other polar materials, leading to the modification of crystal shape and lattice. This approach, which we term complexation-mediated crystallization, has been applied to the crystallization of simple organic salts and to the formation of metal sulfides. The resulting crystal morphologies and structures are presented, as are the structures of an unusual potassium complex of 18-crown-6 and crown ether complexes of lead (II) acetate, hexaaquozinc(II), and aquo(trichloro)zinc(II).