Above room temperature dielectric switchable organic co-crystal [C4H4O4]⋅[C3H9N] with Hirshfeld surface analyses

Abstract

A new co-crystal [C 4 H 4 O 4 ]∙[C 3 H 9 N] was synthesized, where [C 4 H 4 O 4 ]=fumaric acid and [C 3 H 9 N]= isopropylamine. A reversible phase change happened at 352/357 K and it belongs to a homogenous phase change. Hirshfeld surface analyses reveal that three interactions of H⋅⋅⋅H, H⋅⋅⋅O and H⋅⋅⋅C contribute to more than 90% the total forces. Dielectric anomalies were also observed accompanied with structural phase change. • The forces of the H⋅⋅⋅H, H⋅⋅⋅O and H⋅⋅⋅C bond interactions by Hirshfeld surface analyses are different at the high and low dielectric states. We report a new dielectric phase change co-crystal [C 4 H 4 O 4 ]⋅[C 3 H 9 N] 1 , among which [C 4 H 4 O 4 ] is fumaric acid and [C 3 H 9 N] is isopropylamine / IPA. Single-crystal X-ray measurements show space group of 1 belongs to monoclinic P 2 1 / c space group, and a homogeneous phase change occurs. Hirshfeld surface analyses reveal that three interactions of H⋅⋅⋅H, H⋅⋅⋅O and H⋅⋅⋅C contribute more than 90 % to the total forces, and the forces of the three bonds are different at different phases. \