Crystallization Behavior of Coordination Polymers. 2. Surface Micro-Morphology and Growth Mechanisms of [Cu(bpp)3Cl2]·2H2O by in Situ Atomic Force Microscopy

Crystal growth of the one-dimensional coordination polymer [Cu(1,3-bis(4-pyridyl)propane)3Cl2]·2H2O was investigated in aqueous solutions by in situ atomic force microscopy. Details about the growth mechanisms of the {001} form at low supersaturation were obtained. In particular, growth hillocks due to simple and complex dislocation sources were observed as the only active mechanism. The thinnest steps observed on {001} faces and delimiting growth hillocks were d002 layers, in accordance with the elementary growth layer expected from the systematic extinction conditions of space group I2/a and hence from Bravais−Friedel−Donnay−Harker rules and Hartman and Perdok periodic bond chains theory. This feature of the {001} faces suggests that small oligomeric species can be involved in the crystal growth processes. The effects of unknown impurities in the organic ligand upon the growth of crystals of the title compound were also studied.