Synthesis, crystal structure and phase transitions of novel hybrid perovskite: bis(1,2-diaminopropane) di-μ-chloro-bis[diaquadichloromanganate(II)] dichloride

Acta Crystallogr B Struct Sci Cryst Eng Mater. 2023 Aug 1;79(Pt 4):314-319. doi: 10.1107/S2052520623005309. Epub 2023 Jul 7.

Abstract

Single crystals of bis(1,2-diaminepropane) di-μ-chloro-bis[diaquadichloromanganate(II)] dichloride have been prepared by evaporation from ethanoic solution. The triclinic X-ray crystal structure is built as layers of centrosymmetric dimers of [Mn(Cl)4(H2O)2]2- octahedra and 1,2-diaminopropane. The inorganic part consists of Mn octahedra sharing one edge and distributed in the basal ac plane along the a direction. These doubly negative charged layers are separated along the b axis by a positively charged diamine propane layer. One Cl- anion contributes to the electroneutrality of the crystal interacting with both inorganic - through a hydrogen bond network to the two water molecules coordinated to Mn - and organic layers via the NH3+ ammonium group. Differential scanning calorimetry shows two endothermic main peaks at T = 366 K and T = 375 K related to the release of the water molecules. The resulting dehydrated material is C-centered monoclinic as shown by powder X-ray diffraction.

Keywords: crystal structure; difference scanning calorimetry; lead-free hybrid perovskites; phase transitions.