Synthesis and luminescence properties of apically homoleptic octahedral rhenium clusters with pyrazole and 3,5-dimethylpyrazole

Interaction of cluster anions [{Re₆Q₈}X₆]^4−/3− (Q = S or Se; X = Cl, Br or I) with molten pro-ligands – pyrazole (pzH) and 3,5-dimethylpyrazole (3,5-Me₂pzH) has led to the formation of cationic apically homoleptic cluster complexes [{Re₆Q₈}L₆]²⁺ (L = pzH or 3,5-Me₂pzH). All new compounds were characterized by a set of physicochemical properties such as X-ray diffraction analyses on crystals and powders, FTIR and NMR spectroscopies. Synthesis of the complete series of pyrazole complexes and finishing the earlier series of 3,5-dimethylpyrazole complexes with different halogens in addition to the previously described [{Re₆Q₈}(3,5-Me₂pzH)₆]Br₂·2(3,5-Me₂pzH) (Q = S, Se) allowed us to study dependence of luminescence properties on the nature of the inner or outer ligands as well as counterions in detail.