Interplay of Crystal Structures, Thermal Properties, and Magnetism in Zero‐Dimensional Hybrid Transition Metal Bromides

Comprehensive Summary This paper investigates the structure‐property relationships of three zero dimensional (0D) organic‐inorganic hybrid metal halides, focusing on the influence of metal cations on their thermal and magnetic properties. Three transition metal bromides—MnBr 2 , FeBr 3 , and CuBr 2 —were selected to coordinate with a large organic ion, (C 6 H 5 ) 3 PCH 3 + , to form 0D hybrid structures. By maintaining the organic component constant and varying the metal centres, we explore how the metal cation affects the structural characteristics, thermal and magnetic properties using differential scanning calorimetry (DSC), heat capacity measurements and magnetic measurements. The results indicate the influence of metal cations on packing styles and intermolecular interactions of 0D hybrid metal halides, which contribute to the different thermal and magnetic behaviours. Through varying metal cation, it is possible to tune properties by affecting structural characteristics, which could be significant for designing and optimizing devices and applications. In particular, the Fe‐phase is multiferroic below 11 K, i.e. , ferroelastic, ferroelectric and weakly ferromagnetic.