Synthesis, Characterization, and Photoluminescent Properties of ZnII, CdII, and HgII Complexes with N,O Hybrid Pyrazole Ligand

The synthesis and characterization by elemental analysis, mass spectrometry, conductance measurements, IR, H-1, and C-13 NMR spectroscopies of compounds with the general formula [MCl2(L)(2)], where M=Zn (1), Cd (2), or Hg (3) and L=1-(2-hydroxyethyl)-3,5-dimethylpyrazole have been described. The Cd-113{H-1} and Hg-199{H-1} NMR spectra were also measured to investigate the coordination environment of the metal in solution. The structure of complex [ZnCl2(L)(2)] was determined by single-crystal structure analysis. The extended structure revealed a 1D chain caused by several O-H center dot center dot center dot CH3 intermolecular interactions. Moreover, we have determined the fluorescent properties of complexes 1-3; it was found that L demonstrates the higher sensibility to Hg-II ion, one of the most toxic agent in the environment. The preliminary results indicate that L could have a promising future for the detection of mercury in real environmental samples.