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.