Jump to main content
Jump to site search


The influence of intermolecular coupling on electron and ion transport in differently substituted phthalocyanine thin films as electrochromic materials: a chemistry application of the Goldilocks principle

Author affiliations

Abstract

The transport of both electrons and ions in organic mixed ionic and electronic conductors such as phthalocyanines, is essential to allow redox reactions of entire films and, hence, to impart electrochromism. Thin films of a new type, tetrakis-perfluoroisopropyl-perfluoro phthalocyanine, F40PcCu of different thicknesses were obtained via vapor deposition. The extent of the intermolecular coupling within the F40PcCu films established by van der Waals interactions was investigated by in situ optical spectroscopy during film growth. The transfer of electrons and diffusion of counter cations in these films, as well as their electrochromic performance were characterized by electrochemical and spectroelectrochemical measurements with an aqueous solution of KCl as electrolyte. A moderate degree of intermolecular interaction of the F40PcCu molecules in the solid state was observed, compared to non-fluoroalkylated perfluoro phthalocyanine, F16PcCu and octakis-perfluoroisopropyl-perfluorophthalocyanine, F64PcCu, which exhibit stronger and weaker coupling, respectively. The replacement of F by perfluoroisopropyl is, thereby, established as a valuable approach to tune this coupling of chromophores and, hence, the transport coefficients of electrons and ions in the solid films. Reversible changes of the films upon reduction and intercalation of K+ counter ions and re-oxidation and expulsion of the counter ions were confirmed by simultaneously measured optical absorption spectra. Thin films of F40PcCu showed a well-balanced, equally fast transport of electrons and ions. The films provided a fast and reversible switching process over at least 200 cycles indicating the stability of these materials.

Graphical abstract: The influence of intermolecular coupling on electron and ion transport in differently substituted phthalocyanine thin films as electrochromic materials: a chemistry application of the Goldilocks principle

Back to tab navigation

Supplementary files

Article information


Submitted
12 Dec 2019
Accepted
26 Feb 2020
First published
26 Feb 2020

Phys. Chem. Chem. Phys., 2020, Advance Article
Article type
Paper

The influence of intermolecular coupling on electron and ion transport in differently substituted phthalocyanine thin films as electrochromic materials: a chemistry application of the Goldilocks principle

T. H. Q. Nguyen, M. Pelmuş, C. Colomier, S. M. Gorun and D. Schlettwein, Phys. Chem. Chem. Phys., 2020, Advance Article , DOI: 10.1039/C9CP06709D

Social activity

Search articles by author

Spotlight

Advertisements