Temperature‐Induced Irreversible Phase Transition From Perovskite to Diamond But Pressure‐Driven Back‐Transition in an Ammonium Copper Formate

Abstract

The compound [CH3CH2NH3][Cu(HCOO)3] undergoes a phase transition at 357 K, from a perovskite to a diamond structure, by heating. The backward transition can be driven by pressure at room temperature but not cooling under ambient or lower pressure. The rearrangement of one long copper–formate bond, the switch of bridging‐chelating mode of the formate, the alternation of N−H⋅⋅⋅O H‐bonds, and the flipping of ethylammonium are involved in the transition. The strong N−H⋅⋅⋅O H‐bonding probably locks the metastable diamond phase. The two phases display magnetic and electric orderings of different characters.

Advances, Updates, and Analytics for the Computation-Ready, Experimental Metal–Organic Framework Database: CoRE MOF 2019

“…The largest increase in the surface area was observed for MAGNEQ. 64 We also find that the accessible volumetric surface area decreases more than 100 m 2 /cm 3 for 168 structures (∼1.9% of 8815) upon removal of the bound solvent. This is because the loss of surface area from the solvent molecules is greater than the MOF surface area exposed upon removing the bound solvent.…”

Methylammonium Lead Trihalide Perovskite Solar Cell Semiconductors Are Not Organometallic: A Perspective

“…There have been a number of similar other AMY 3 metal‐organic perovskite compounds reported . Both the A‐ and M‐site cations in these have been synthesized to be different.…”

“…Yes, it is possible to use any such ligand cation to design the MOFs. We have already given above some examples of various metal‐organic perovskite frameworks that are built with a variety of A‐site cations . However, it is worth stressing that each organic cation has its own molecular size, acidity, basicity and adoptability.…”