Room-Temperature Bistability in a Ni-Fe Chain: Electron Transfer Controlled by Temperature, Pressure, Light, and Humidity.

Abstract

Bistable and stimuli-responsive molecule-based materials are promising candidates for the development of molecular switches and sensors for future technologies. The CN-bridged {NH4 [Ni(cyclam)][Fe(CN)6 ]⋅5 H2 O}n chain exists in two valence states: NiII -FeIII (1HT ) and NiIII -FeII (1LT ) and shows unique multiresponsivity under ambient conditions to various stimuli, including temperature, pressure, light, and humidity, which generate measurable response in the form of significant changes in magnetic susceptibility and color. The electron-transfer phase transition 1LT ↔1HT shows room-temperature thermal hysteresis, can be induced by irradiation, and shows high sensitivity to small applied pressure, which shifts it to higher temperatures. Additionally, it can be reversibly turned off by dehydration to the {NH4 [NiII (cyclam)][FeIII (CN)6 ]}n (1 d) phase, which features the NiII -FeIII valence state over the whole temperature range, but responds to pressure by yielding NiIII -FeII above 1.06 GPa.

• Authors: Mateusz Reczyński, Dawid Pinkowicz, Koji Nakabayashi, Christian Näther, Jan Stanek, Marcin Kozieł, Justyna Kalinowska-Tłuścik, Barbara Sieklucka, Shin-Ichi Ohkoshi, Beata Nowicka
• Journal: Angewandte Chemie (International ed. in English) (Angew Chem Int Ed Engl) Vol. 60 Issue 5 Pg. 2330-2338 (Feb 01 2021) ISSN: 1521-3773 [Electronic] Germany
• PMID: 33124080 (Publication Type: Journal Article)
• Copyright: © 2020 Wiley-VCH GmbH.