1D Copper(II)-Aroylhydrazone Coordination Polymers: Magnetic Properties and Microwave Assisted Oxidation of a Secondary Alcohol

The 1D Cu(II) coordination polymers [Cu-3(L-1)(NO3)(4)(H2O)(2)](n) (1) and [Cu-2(H2L2)(NO3)(H2O)(2)](n)(NO3)(n) (2) have been synthesized using the aroylhyrazone Schiff bases N'(1),N'(2)-bis(pyridin-2-ylmethylene)oxalohydrazide (H2L1) and N'(1),N'(3)-bis(2-hydroxybenzylidene)malonohydrazide (H4L2), respectively. They have been characterized by elemental analysis, infrared (IR) spectroscopy, UV-Vis spectroscopy, electrospray ionization mass spectrometry (ESI-MS), single crystal X-ray diffraction and variable temperature magnetic susceptibility measurements (for 2). The ligand (L-1)(2-) coordinates in the iminol form in 1, whereas the amide coordination is observed for (H2L2)(2-) in 2. Either the ligand bridge or the nitrate bridge in 2 mediates weak antiferromagnetic coupling. The catalytic performance of 1 and 2 has been investigated toward the solvent-free microwave-assisted oxidation of a secondary alcohol (1-phenylethanol used as model substrate). At 120 degrees C and in the presence of the nitroxyl radical 2,2,6,6-tetramethylpiperydil-1-oxyl (TEMPO), the complete conversion of 1-phenylethanol into acetophenone occurs with TOFs up to 1,200 h(-1).