What can only occur in supramolecular systems; first solid-state conversion of micro to nanostructures without any treatment in environmental conditions

The sonochemical reaction between lead acetate and 5-chloro-8-hydroxyquinoline resulted in formation of one-dimensional pencil shaped [Pb2(5-Clq-8-ol)2(OAc)2]n (1) supramolecular polymer microrods. After three months, these crystalline microrods convert to amorphous nanoparticles of 1 without any treatment in environmental conditions. In the absence of ultrasonic waves, bulk sample of 1 with microrods morphology was obtained again. Surprisingly, these microrods convert to nanorods of 1 with more crystalline structure after three months. It seems that the sonochemical prepared sample of 1 has less crystalline stability than the bulk sample. Although conversion of bulk to nanostructures is very rare in other materials, existence of weak secondary interactions in supramolecular systems, become it possible.