New tetradentate Schiff base Cu(II) complexes: synthesis, physicochemical, chromotropism, fluorescence, thermal, and selective catalytic oxidation

Abstract Three neutral Cu(II)/? 4 -NNNO Schiff base complexes ( 1-3 ) were prepared from the (E)-4-nitro-2-(((2-(piperazin-1-yl)ethyl)imino)methyl)phenol, tetradentate (SB) ligand, and corresponding copper(II) salts. The new SB its fully characterized by CHN-EA, standard spectroscopic, thermal, fluorescence analyses. formation of was monitored EDX, FT-IR, UV-Vis. chromotropism studies reflected remarkable findings, in which bathochromic solvato- thermochromism shifts detected. turn-off-on halochromism phenomena observed acidic basic medium. On other hand, free ligand turned off via complexation to Cu(II) center. In presence H 2 O as green oxidant under mild oxidation catalytic condition, three successfully catalyzed benzaldehyde benzyl alcohol.