Biography
Biography: Yu-Wu Zhong
Abstract
Electro-active and electrochromic materials have received a wide range of applications. The incorporation of a metal ion gives rise to new functions that are not present in common organic materials. However, the applications of electro-active organometallic materials are often hampered by their high redox potentials and difficulty in film formation. Recently, we have been interested in the design and construction of electro-active systems with cyclometalated ruthenium and triarylamine as the charge-bearing sites. These materials show strong electronic coupling and multiple reversible redox processes in low positive potential window. After modified with vinyl or triphenyl units, these can be smoothly deposited onto ITO electrode surfaces by in situ electropolymerization. The obtained films exhibit multistate NIR electrochromism with long retention time, good contrast ratio, and low switching potential. The response is about a few seconds. Depending on the number of redox sites, 3 - 5 step redox switching were realized. These films have been used for the demonstrations of flip-flop or flip-flap-flop memory with electrochemical potentials as input signals and absorbance at different wavelengths as output signals. In addition to electropolymerized films, self-assembled monolayer films of these complexes were obtained and they are useful in molecular-scale NIR electrochromism and electrochemically-gated single molecular conductance.