Geometric isomeric pairs: synthesis, structure, thermal decomposition and magnetic properties of cis- and trans-[Cr(mal)(bpy)(H2O)2][NO3]·xH2O (H2mal=malonic acid, bpy=2,2′-bipyridine)

Procedures are given for the preparation and isolation of cis-[Cr(mal)(bpy)(H2O)2][NO3]·3H2O (I) and trans-[Cr(mal)(bpy)(H2O)2][NO3]·H2O (II) (H2mal=malonic acid, bpy=2,2′-bipyridine). The single crystals X-ray structure of cis-compound reveals that the cations and anions as well as cations between cations are linked into hydrogen-bonded chains. Unfortunately, little structural information is available for the trans compound II (only isotropic cation refinement), nevertheless, from this result is observed that there also exists a hydrogen-bonded network between anion units. Thermal analysis and magnetic behaviour for both compounds were studied.