Abstract
New hybrid iron-formate
perovskites have been obtained in high-pressure reactions. Apart from the
pressure range, also the liquid environment of the sample regulates the course
of transformations. Formate α-DmaFe2+Fe3+For6, when
compressed in oil and in isopropanol at 1.40 GPa, transforms to a new phase γ, different than that phase β obtained at
low-temperature. In glycerol
phase α can be compressed to 1.40 GPa, but then reacts to DmaFe2+For3,
with all Fe(III) cations reduced, surrounded by amorphous iron
formate devoid of Dma
cations. Another
mixed-valence framework Dma3[Fe2+3Fe3+For6]2·CO2,
can be produced from phase α incubated in methanol and ethanol at 1.15 GPa. These
pressure-induced environment-sensitive modifications have been rationalised by
the volume effects involving the oxidation states of Fe(II) and
Fe(III), their high- and low-spin states as well as the properties of pressure transmitting media. The topochemical
redox reactions controlled by pressure and the liquid environment offer new
highly efficient, safe and environment-friendly reactions leading to new advanced
materials and their post-synthesise modifications.