Differences in thermal expansion and motion ability for herringbone and face-to-face π-stacked solids

Colossal Anisotropic Thermal Expansion in a Diazo‐Functionalized Compound with Switchable Solid‐State Behavior

“…Here, we synthesized diazo‐I as reported and single crystals were grown by slow evaporation from toluene [17] . To investigate the possible convergence at high temperature, we conducted a VT SCXRD experiment by mounting the crystal at 320 K followed by cooling gradually to 270 K in 10 K increments (Table S1–S2) [21]…”

Forced topochemistry of a solid-state Diels–Alder reaction by encapsulation in epoxy glue

“…[19][20][21] Single crystals that have undergone reactions in the solid state have been shown to occur under different conditions such as light, 7,22 heat [23][24][25] or pressure, [26][27][28][29][30] giving way to a variety of reactions with crystal products showing physical properties ranging from the formation of porous molecules [31][32][33] to mechanical effects. [34][35][36] These reactions fall in the domain of supramolecular chemistry, as intermolecular bonds between discrete molecules can lead to favourable conditions under which reactions can occur. 2 Topochemistry was first described by Kohlschütter as reactions that can occur in the solid state where the 3D nature of the crystal influences the structures and supramolecular arrangement of molecules in a crystal system, affecting the mechanism of the reaction.…”

Colossal Anisotropic Thermal Expansion in a Diazo‐Functionalized Compound with Switchable Solid‐State Behavior

“…Recently, we described a series of di‐halogenated compounds wherein the degree of solid‐state pedal motion was influenced by the identity of the functional group bridging the aromatic rings (olefin, imine, or azo) and larger TE occurred along the direction where motion happened in the solids [17] . In the previous study, one compound, 1,4‐bis(( E )‐(4‐iodophenyl)diazenyl)benzene ( diazo‐I , Figure 1b), underwent pedal motion, as well as a conformational switch in the major site orientation within one of the two crystallographically unique molecules between 250 and 270 K. Upon further investigation after that study, we determined that the β angle of the unit cell also began approaching 90° upon heating, which could result in a space group change.…”