Synthesis, crystal structures and luminescent properties of zinc and manganese complexes from Demko–Sharpless reaction

The synthesis and crystal structure of two new complexes (Zn and Mn) containing tetrazolyl ligands are described. In situ [2+3] cycloaddition reactions of fipronil, (fipronil = (±)-5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfinyl]-1H-pyrazole-3-carbonitrile) with sodium azide in the presence of ZnCl2 or MnCl2 as a Lewis acid (Demko–Sharpless tetrazole synthesis method) under hydrothermal (solvothermal) reaction conditions gave [Zn(L)2](H2O)2] · H2O, 1 and [Mn(L)2](H2O)2] · H2O, 2, (HL = (±)-5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfinyl]-1H-pyrazole-3-tetrazole). The central metals in both complexes are six coordinated, which connected by two water molecules, two nitrogen atoms from different tetrazolyl groups and two nitrogen atoms from pyrazolyl rings respectively. Photoluminescence studies reveal that both title complexes exhibit strong blue fluorescent emissions at λmax = 383 nm for 1 and 411 nm for 2 respectively in the solid state at room temperature.