Environment-Controlled Post-Synthetic Modifications of Iron Formate Frameworks

2019-03-04T19:16:15Z (GMT) by Szymon Sobczak Andrzej Katrusiak
<b>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-DmaFe<sup>2+</sup>Fe<sup>3+</sup>For<sub>6</sub><a>, when compressed in oil and in isopropanol at 1.40 GPa, transforms to a new</a><a> phase<i> </i></a><i>γ</i>, different than that phase β obtained at low-temperature. In <a></a><a></a><a></a><a></a><a></a><a>glycerol</a> phase α can be compressed to 1.40 GPa, but then <a></a><a>reacts </a>to <a></a><a>DmaFe<sup>2+</sup>For<sub>3</sub>, with all Fe(III) cations reduced, </a>surrounded by amorphous iron formate <a></a><a></a><a></a><a>devoid </a>of Dma cations. <a></a><a></a><a>Another mixed-valence framework Dma<sub>3</sub>[Fe<sup>2+</sup><sub>3</sub>Fe<sup>3+</sup>For<sub>6</sub>]<sub>2</sub>·CO<sub>2</sub>, can be produced from phase α incubated in methanol and ethanol at 1.15 GPa</a>. 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.</b>