The materials of ammonium metal formate framework: structures, phase transitions and functionalities

Abstract

The materials of ammonium metal formate framework belong to a unique class of metal-organic frameworks. Such materials have received much attention in past few decades because they can undergo structural, electric and magnetic phase transitions along the temperature, pressure, and/or other dimensionalities, and show the accompanied di-/ferro-/antiferro-electricities, magnetic properties, multiferroics, negative thermal expansion, negative compressibility, bond re-arrangement, mechanical properties, and so on. In this review, we present the development about the research of ammonium metal formate frameworks composed of octahedral metal ions, mainly based on our own works, together with some related and important results by other researchers, and provide perspectives for the researches on these unique and interesting materials.

A highly polar hybrid perovskite of [FCH2CH2NH3][Mn(HCOO)3]

“…The compound FetaMn was prepared by the conventional solution chemistry methods (see Experimental Section), now probably the most convenient ones for preparing AMFF materials. [4][5][6] Since the ammonium, 2-fluoroethylammium, came directly from the starting acidic chemical of 2-fluoroethylamine hydrochloride, triethylamine was used to neutralize formic acid in order to provide formate ligands needed. This proves again that the bulky triethylammonium is too large to be involved in the proverskite AMFFs.…”

“…Up to date there have been more than 100 AMFF perovskite materials reported. [6] The mono-ammoniums AH cover the simplest NH 4…”