Near-infrared electrochromism of multilayer films of a cyclometalated diruthenium complex prepared by layer-by-layer deposition on metal oxide substrates

• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2019,（12）
• 页码范围: 1675-1685
• 页数: 11页
• 语种: 英文

摘要

A cyclometalated diruthenium complex 2 bridged by 1,2,4,5-tetra(pyrid-2-yl)benzene with six carboxylic acid groups at two ends was synthesized.Monolayer and multilayer films FTO/TiO2/(2)n(Zr) (n=1,2) and FTO/SnO2∶Sb/(2)n(Zr) (n=1-4) have been prepared via interfacial layer-by-layer coordination assembly of 2 with zirconium(Ⅳ) ions.All films show two consecutive redox couples in the potential range between 0 and +1.0 V vs.Ag/AgC1.These films exhibit reversible near-infrared electrochromism upon switching ofredox potential.The response time of the films on SnO2∶Sb is around a few seconds,while that on TiO2 is around a few tens of seconds.The film deposition cycles were found to have a great impact on the electrochromic performance.Among six films examined,the two-layered film on SnO2∶Sb displays the best balanced performance with a contrast ratio of 56％ at 1,150 nm and good cyclic stability (9％ loss of contrast ratio after 1,000 continuous double-potentialswitching cycles),which is superior to that of the previously reported electropolymerized films of a related diruthenium complex with the same bridging ligand.In addition,the X-ray photoelectron spectroscopy,scanning electron microscopy,and electron transfer mechanism of these films have been investigated.