Exploring the effect of pressure on the crystal structure and caloric properties of the molecular ionic hybrid [(CH)NOH][CoCl].

The hybrid metal halide [(CH)NOH]CoCl exhibits a first-order phase transition at ∼ 343 K. Its crystal structure and caloric properties respond significantly to moderate pressures (1-1000 bar), demonstrating potential for applications in emerging solid-state refrigeration technologies.

Empowering CO Eco-Refrigeration With Colossal Breathing-Caloric-Like Effects in MOF-508b.

Today, ≈20% of the electric consumption is devoted to refrigeration; while, ≈50% of the final energy is dedicated to heating applications. In this scenario, many cooling devices and heat-pumps are transitioning toward the use of CO as an eco-friendly refrigerant, favoring carbon circular economy. Nevertheless, CO still has some limitations, such as large operating pressures (70-150 bar) and a critical point at 31 °C, which compromises efficiency and increases technological complexity.

Anomalous and colossal thermal expansion, photoluminescence, and dielectric properties in lead halide-layered perovskites with cyclohexylammonium and cyclopentylammonium cations.

A detailed study of lead halide-layered perovskites with general formula APbX (where A is cyclohexylammonium (CHA) or cyclopentylammonium (CPA) cation and X is Cl or Br anion) is presented. Using variable temperature synchrotron X-ray powder diffraction, we observe that these compounds exhibit diverse crystal structures above room temperature. Very interestingly, we report some unconventional thermomechanical responses such as uniaxial negative thermal expansion and colossal positive thermal expansion in a perpendicular direction.

Discovery of Colossal Breathing-Caloric Effect under Low Applied Pressure in the Hybrid Organic-Inorganic MIL-53(Al) Material.

In this work, "breathing-caloric" effect is introduced as a new term to define very large thermal changes that arise from the combination of structural changes and gas adsorption processes occurring during breathing transitions. In regard to cooling and heating applications, this innovative caloric effect appears under very low working pressures and in a wide operating temperature range. This phenomenon, whose origin is analyzed in depth, is observed and reported here for the first time in the porous hybrid organic-inorganic MIL-53(Al) material.