Electrochromic Bis(terpyridine)metal Complex Nanosheets

A series of electrochromic metal
complex nanosheets comprising
1,3,5-tris­(4-(2,2′:6′,2″-terpyridyl)­phenyl)­benzene
or 1,3,5-tris­((2,2′:6′,2″-terpyridyl)­ethynyl)­benzene
and Fe2+ or Co2+ was synthesized. The preparation
of multilayered nanosheets was achieved by liquid/liquid interfacial
synthesis using an organic ligand solution and an aqueous metal–ion
solution. The resultant nanosheet had a flat, smooth morphology and
was several hundreds of nanometers thick. Upon its deposition on an
indium tin oxide (ITO) electrode, the nanosheet underwent a reversible
and robust redox reaction (Fe3+/Fe2+ or Co2+/Co+) accompanied by a distinctive color change.
Electrochromism was achieved in a solidified device composed of the
nanosheet, a pair of ITO electrodes, and a polymer-supported electrolyte.
The combination of Fe2+ and Co2+ nanosheets
in one devicedeposited on each ITO electrodedemonstrated
dual-electrochromic behavior.