Interaction Studies between Photochromic Spiropyrans and Transition Metal Cations: The Curious Case of Copper

Abstract

A series of four spiropyrans bearing different substituents on the indolic nitrogen were synthesized and their capability of binding mono and bivalent transition metal cations in solution was assessed via UV-visible absorption spectroscopy. All the compounds responded selectively to the presence of Cu(ii) ions producing intense absorption bands in the visible region of their spectra. Bidimensional 1H-NMR and MALDI-TOF MS spectroscopies revealed the formation of SP dimers mediated by Cu(ii). This is the first example of cross-coupling mediated by copper(ii) in mild conditions causing the symmetric dimerization of spiropyran dyes. © The Royal Society of Chemistry 2012.

Silvia Giordani

Full Professor Chair of Nanomaterials

My research interests are in the design, synthesis, and characterization of hybrid smart nanomaterials for biomedical, energy and environmental applications