Nucleation and crystal growth of molecular solvates with several conformations both in solution and in solid state; application to some hydrated copper(II) sulfoxinates

Abstract

The nucleation and growth of copper(II) 5-sulfonic-8-hydroxyquinolinates · nH 2O ( n = 2, 3 and 4) are examined. Modellization of the relations between water molecules acting as solvent and the complexes shows that the closer the molecular confirmations in solid state and in solution, the higher the nucleation rate of solids. This conclusion is valid within that range of temperature where the energy barrier between the conformations in solution is high enough to limit interconversion. The periodic bond chain (PBC) theory is examined in the case of several molecules in the asymmetric unit. Sub-slices and multi order slices are defined for particular orientations and are shown to have different growth rates. Generalization to other organic and organometallic compounds with independant molecules in the asymmetric unit is discussed. The rôle of sub-slices and second order slices in modifying the crystal surfaces and crystal growth mechanisms is envisaged for different parameters, mainly temperature, solvent and supersaturation.