H-bonded supramolecular assembly via proton transfer: Isolation, X-ray crystallographic characterization and SOD mimic activity of [Cu(dipic)2]2[PA-H]4·5H2O

The title proton transfer complex was isolated from the reaction of CuCl2·2H2O with pyridine-2,6-dicarboxylic acid (dipic-H2) in presence of 3-amino-1-propanol (PA) under reflux condition. It was thoroughly characterized by FAB-mass, FT-IR, electronic (ligand field), EPR spectroscopic and X-ray crystallographic techniques. The complex crystallizes in the space group C1c1 of the monoclinic system. The unit cell parameters are, a = 17.247(5), b = 20.058(5) Å, c = 15.320(4) Å and β = 109.235(5)°. Extensive H-bonding between the complex anion [Cu(dipic)2]2− and the surrounding cations [PA-H]+ results in a 3D network, supported with additional π–π interactions of the ligand (dipic)2− neighboring units. The SOD mimic activity of the present complex was also examined using NBT assay.

► A novel proton transfer complex is prepared. ► It has been characterized by spectral and X-ray studies. ► X-ray shows composition [Cu(dipic)2]2[PA-H]4·5H2O. ► 3D network exists via H-bonding and π–π interactions. ► SOD mimic activity is also evaluated.