SELECTIVE CRYSTALLIZATION BETWEEN CUSO4-CENTER-DOT-5H(2)O AND NA2SO4-CENTER-DOT-7H(2)O UNDER A MONOLAYER

Two selections have been found to occur in the crystal growth induced by a monolayer of 9-(hexadecylimino)-4,5-diazafluorene. Between CuSO4 . 5H(2)O and Na2SO4 . 7H(2)O, although both were supersaturated, only the former was chosen to nucleate under the monolayer and the latter f ormed at the bottom of the container. Furthermore, among all of the cr ystal faces of CuSO4 . 5H(2)O the (010) face was selected by the monol ayer and the crystallization was oriented. In these processes, the mon olayer plays a very important role and acts as a template which can re cognize a certain crystal and a certain crystal face. This is due to s pecific molecular interactions between ions and the hydrophilic head g roups of the monolayer, and the influence of some factors including io n binding, lattice matching and structural complementarity. Using the principles of hard-soft acid-base theory, coordination theory and by c omputer simulation, it was found that the dimensions of the (010) face of CuSO4 . 5H(2)O match those of the monolayer very well.