https://www.selleckchem.com/products/favipiravir-t-705.html [DMHy]Mn(HCOO)3 (DMHy+ = dimethylhydrazinium cation) is an example of an organic-inorganic hybrid adopting perovskite-like architecture with the largest organic cation used so far in the synthesis of formate-based hybrids. This compound undergoes an unusual isosymmetric phase transition at 240 K on heating. The mechanism of this phase transition has a complex nature and is mainly driven by the ordering of DMHy+ cations and accompanied by a significant distortion of the metal-formate framework in the low temperature (LT) phase. In this work, the Density Functional Theory (DFT) calculations and factor group analysis are combined with experimental temperature-dependent IR and Raman studies to unequivocally assign the observed vibrational modes and shed light on the details of the occurring structural changes. The spectroscopic data show that this first-order phase transition has a highly dynamic nature, which is a result of balanced interplay combining re-arrangement of the hydrogen bonds and ordering of DMHy+ cations. The tight confinement of organic cations forces simultaneous steric deformation of formate ions and the MnO6 octahedra.Clay raw materials are diverse in terms of their mineral composition, as well as the content of colouring oxides and their physical properties. Determining the suitability of raw materials for various purposes requires comprehensive studies on their properties, as well as their appropriate correction, which is possible through the use of appropriate modification techniques. One of the most commonly used technologies for the enrichment of clay raw materials is to subject them to high temperatures, which, depending on the temperature regime used in the technological process, may cause the decomposition and removal of some addditional components (e.g., carbonates), as well as the removal of water and dehydroxylation of clay minerals, reversible structural changes, and the complete