Fast Detection of Water and Organic Molecules by a Change of Color in an Iron(II) Microporous Spin-Crossover Coordination Polymer

Here we present a novel three-dimensional iron­(II) spin-crossover porous coordination polymer based on the bis­(1,2,4-triazol-4-yl)­adamantane (tr2ad) ligand and the [Au­(CN)2]− metalloligand anions with the formula {Fe3(tr2ad)4[Au­(CN)2)]2}­[Au­(CN)2]4·G. The sorption/desorption of guest molecules, water, and five/six-membered-ring organic molecules is easily detectable because the guest-free and -loaded frameworks present drastically distinct coloration and spin-state configurations.