Frontiers in Chemistry (Mar 2020)

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

  • Manas Sutradhar,
  • Elisabete C. B. A. Alegria,
  • Elisabete C. B. A. Alegria,
  • Tannistha Roy Barman,
  • M. Fátima C. Guedes da Silva,
  • Cai-Ming Liu,
  • Armando J. L. Pombeiro

DOI
https://doi.org/10.3389/fchem.2020.00157
Journal volume & issue
Vol. 8

Abstract

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The 1D Cu(II) coordination polymers [Cu3(L1)(NO3)4(H2O)2]n (1) and [Cu2(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 (L1)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°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.

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