New conductive molecular composites: aniline derivatives as guest molecules encapsulated and polymerized within the channels of the host 3D-coordination polymers [(Me3E)3Fe(CN)6]∞ where E=Sn or Pb

Abstract

New conductive molecular composites have been prepared by chemical oxidation of polyanilines within the expandable wide channels of the 3D-coordination polymers [(Me₃E)₃Fe(CN)₆ ]_∞ where E=Sn or Pb, in the presence and absence of HCl. The UV and visible absorption spectra of the protonated and deprotonated molecular composites are compared with those of polyanilines, polyemeraldine and nigrosine. The protonated molecular composites exhibit conductivities higher than the deprotonated ones. Also, polymerization of some aniline derivatives within the channels of the 3D-polymers, in absence of HCl, leads to vast improvement in conductivity owing to self protonation of the polyemeraldine base. The dramatic shift in optical response of the molecular composite containing polyemeraldine base with change in pH could be used as an optical pH sensor over the pH range investigated.