Electrochemical Properties and Electrochromism of 6-Aryl-1,3-bis(trimethylsilyl)fulvenes and Their Derivatives.

In this study, we have disclosed intriguing electrochromic properties of 6-aryl-1,3-bissilylfulvenes. The electrolyte solutions (0.1 M n-Bu4NClO4 in acetonitrile or dichloromethane) of some 6-aryl-1,3-bissilylfulvenes showed notable color changes when superimposed negative voltages were applied to the solutions. Investigation of the substituents at position 6 revealed that the solution of 1,3-bissilyl-6-anthracenylfulvene exhibited chromic changes under both applied superimposed negative and positive voltages and exhibited a three-color electrochromism. Electrochromic properties of 1,6-diarylfulvenes derived from 6-aryl-1,3-bissilylfulvenes were also investigated. The aryl group at position 1 also contributed to the electrochromism of fulvenes.