Near-IR Electrochromism in Electrodeposited Thin Films of Cyclometalated Complexes

Homogeneous thin films of controlled thickness obtained from cyclometalated complexes of general formula [(C boolean AND N)M(O boolean AND N)], where M = Pd(II) or Pt(II), H(C boolean AND N) = 2-phenylpyridine and, respectively, 2-thienylpyridine and H(O boolean AND N) = a triphenylamine functionalized Schiff base, have been deposited by oxidative electropolymerization. The films have been electrochemically and morphologically characterized. The metallopolymeric thin films present stable reversible redox behavior and typical cauliflower-like textures in agreement with a nucleation growth electropolymerization mechanism However, the film growth is greatly influenced by the nature complexes to promote the 3D growth. Furthermore, a complete electrodeposited films showing near-IR absorption in the oxidized state, of the metal center, with a higher tendency of the Pt spectroelectrochernical study has been performed on electrodeposited films showing near-IR absorption in the oxidized state, high contrast ratios (up to 65%) and low response times.