Metal selective co-ordinative self-assembly of π-donors

Abstract

Metal selective co-ordinative nanostructures were constructed by the supramolecular co-assembly of pyridine appended TTF (TTF-Py) and pyrene (PYR-Py) derivatives in appropriate solvent composition mixtures with metal ions. Microscopic analyses show that TTF-Py shows distinctive morphology with either of these metal ions, forming I-D tapes with 1:1 Pb2 + complex and 2-D sheets with 1:2 Zn2 + complex. A rationale has been provided from molecular level packing for such hierarchical changes. In case of Cu2 + , we have observed an anomalous binding of metal ion to the core sulphur groups causing redox changes in the TTF core. PYR-Py on the other hand is shown to be a fluorescent sensor for Pb2 + , Zn2 + , Hg2 + and Ag + . With different fluorescent response for metal complexes, we essentially obtained similar 1-D assemblies suggesting similar binding modes for all of them. Supramolecular approach through which morphology of an electron donor moiety can be engineered by metal ions can be a new tool in nanoelectronics. Metal selective self-assembly of pyridine appended donors moieties of TTF and Pyrene, to various nanostructures is presented. The supramolecular morphology is greatly dependent on the metal ion and a direct correlation of binding mode with the nanostructures is observed.