Jankowski Robert, Reczyński Mateusz, Chorazy Szymon, Zychowicz Mikołaj, Arczyński Mirosław, Kozieł Marcin, Ogorzały Karolina, Makowski Wacław, Pinkowicz Dawid, Sieklucka Barbara
Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30387, Krakow, Poland.
Chemistry. 2020 Sep 1;26(49):11187-11198. doi: 10.1002/chem.202000146. Epub 2020 Jul 30.
Discrete molecular species that can perform certain functions in response to multiple external stimuli constitute a special class of multifunctional molecular materials called smart molecules. Herein, cyanido-bridged coordination clusters {[Fe (2-pyrpy) ] [M (CN) ] }⋅4 MeOH⋅6 H O (M=Mo (1 solv), M=W (2 solv) and 2-pyrpy=2-(1-pyrazolyl)pyridine are presented, which show persistent solvent driven single-crystal-to-single-crystal transformations upon sorption/desorption of water and methanol molecules. Three full desolvation-resolvation cycles with the concomitant change of the host molecules do not damage the single crystals. More importantly, the Fe M molecules constitute a unique example where the presence of the guests directly affects the pressure-induced thermal spin crossover (SCO) phenomenon occurring at the Fe centres. The hydrated phases show a partial SCO with approximately two out-of-four Fe centres undergoing a gradual thermal SCO at 1 GPa, while in the anhydrous form the pressure-induced SCO effect is almost quenched with only 15 % of the Fe centres undergoing high-spin to low-spin transition at 1 GPa.
能够响应多种外部刺激而执行特定功能的离散分子物种构成了一类特殊的多功能分子材料，称为智能分子。本文报道了氰基桥联配位簇{[Fe(2 - pyrpy)][M(CN)]}⋅4 MeOH⋅6 H₂O（M = Mo（1 solv），M = W（2 solv），2 - pyrpy = 2-(1 - 吡唑基)吡啶），它们在水和甲醇分子的吸附/解吸过程中表现出持续的溶剂驱动单晶到单晶的转变。三个伴随主体分子变化的完全去溶剂化 - 再溶剂化循环不会破坏单晶。更重要的是，Fe - M分子构成了一个独特的例子，其中客体的存在直接影响在Fe中心发生的压力诱导热自旋交叉（SCO）现象。水合相表现出部分SCO，在1 GPa下约四分之二的Fe中心经历逐渐的热SCO，而在无水形式下，压力诱导的SCO效应几乎被淬灭，在1 GPa下只有15 %的Fe中心经历高自旋到低自旋转变。
