Schiff bases of 1,5-diarylpent-4-ene-1,3-diones and their metal complexes: Synthesis, characterization and fluorescent studies

Four Schiff bases (H2L1 to H2L4) were synthesized by the condensation of o-aminophenol and unsaturated diketones (1,5-diarylpent-4-ene-1,3- -diones). Analytical, IR, 1H-NMR mass spectral data revealed their existence in imine?enamine form. Dibasic tetradentate coordination ML complexes (M = Cu(II), Ni(II), Co(II), Zn(II), Cd(II), Hg(II)) was established based on physical, analytical data. The fluorescent studies H2L4 showed that fluorescence emission maxima shifted with increasing polarity hydrogen bonding ability solvent. Paramagnetic Ni(II) Co(II) ions decrease intensity concentration metal ion while diamagnetic Cd(II) Hg(II) have very little influence base H2L4.