Two Consecutive Magneto‐Structural Gas–Solid Transformations in Non‐Porous Molecular Materials

Abstract

Modification of the magnetic properties in a solid-state material upon external stimulus has attracted much attention in the recent years for their potential applications as switches and sensors. Within the field of coordination polymers, gas sorption studies typically focus on porous solids, with the gas molecules accommodating in the channels. Here we present a 1D non-porous coordination polymer capable of incorporating HCl gas molecules, which not only causes a reordering of its atoms in the solid state but also provokes dramatic changes in the magnetic behavior. Subsequently, a further solid-gas transformation can occur with the extrusion of HCl gas molecules causing a second structural rearrangement, which is also accompanied by modification in the magnetic path between the metal centers. Unequivocal evidence of the two-step magnetostructural transformation is provided by X-ray single-crystal diffraction.

Thermal Reactivity in Metal Organic Materials (MOMs): From Single-Crystal-to-Single-Crystal Reactions and Beyond

“…Another example of non-porous materials using a second sphere adduct displaying dynamic behavior upon the release of HCl molecules have been reported by SCSC. Recently, Minguez Espallargas using imidazole and CuCl 2 •2(H 2 O) reported two-consecutive magneto-structural transformations in non-porous materials with a first transformation of a polymeric-to-molecular material (i.e., second sphere adduct) followed by a second structural transformation induced by thermal treatment resulting in a 1D polymeric chain Figure 17 [80].…”

“…Both materials show weak antiferromagnetic behavior. This figure has been reproduced from[80] with permission.…”

Tunable Proton Conductivity and Color in a Nonporous Coordination Polymer via Lattice Accommodation to Small Molecules

“…Nonporous coordination polymers (npCPs) that can act as porous are remarkable materials able to release or incorporate small molecules in their structure via internal lattice reorganization. [ 1 , 2 , 3 ] These molecules are typically weakly coupled to the lattice and can migrate across the crystal, providing npCPs with complex molecular dynamics and an associated wide variety of applications from magnetic switching, [ 1 , 3 , 4 ] gas/vapor adsorption [ 5 , 6 , 7 , 8 ] and sensing, [ 4 , 9 , 10 , 11 ] energy storage, [ 12 ] and catalysis, [ 13 ] even though this is a relatively recent research area. Owing to the weak interactions in the crystal packing, these materials are usually softer than porous coordination polymers (pCP) and metal‐organic frameworks (MOF).…”

Qualitative Guest Sensing via Iron(II) Triazole Complexes

“…Solidstate SCO-active systems are often based on robust porous materials such as metal− o r g a n i c f r a m e w o r k s (MOFs); 29,32,33,42,43 however, non-porous molecular materials can also reversibly sense guest molecules. 18,21,34,35,38,48,49 SCOactive iron(II) molecular systems have also shown great promise in sensing guest molecules in solution. 2,50 Reported studies range from sensing anions in aprotic solvents 51−53 to changes in temperature 54 or pH 55 in aqueous solution to changes in the solvent polarity of organic solvents 28 and aqueous/organic solvent mixtures.…”

“…SCO-active materials are highly sensitive to their environment, which makes them appealing systems for sensing applications, as illustrated by the range of recent studies on that topic. ,,,− These high-profile reports focus on solid-state systems or solution studies to examine the reversible sensing of guests, in particular gas or solvent molecules. Solid-state SCO-active systems are often based on robust porous materials such as metal–organic frameworks (MOFs); ,,,, however, non-porous molecular materials can also reversibly sense guest molecules. ,,,,,, SCO-active iron­(II) molecular systems have also shown great promise in sensing guest molecules in solution. , Reported studies range from sensing anions in aprotic solvents − to changes in temperature or pH in aqueous solution to changes in the solvent polarity of organic solvents and aqueous/organic solvent mixtures. , …”