A Rare Example of a Dimeric Copper(Ii) Complex with a Double Nitrato Κ1-O,O’;Κ2-O Bridge: Synthesis, Crystal Structure, Magnetic Properties and Hirshfeld Surface Analysis

Abstract

We present a very unusual κ1-O,O’;κ2-O nitrate-bridged dinuclear copper(II) complex formulated as [Cu2(NO3)2(L)2] (1), prepared with the NNO-donor Schiff base ligand, 2-(benzothiazol-2-yl-hydrazono)-1,2-diphenyl-ethanone (HL). Compound 1 has been characterized by elemental analysis, ESI-MS, FT-IR, UV-Vis and EPR spectroscopy. Single crystal X-ray diffraction analysis reveals that 1 is a CuII dimer with a double Cu-O-Cu bridge. It crystallizes in the monoclinic P21/n space group. Solution and solid state electronic spectra confirm its identity in both phases. Magnetic susceptibility measurements of 1 reveal the presence of a weak antiferromagnetic Cu-Cu coupling through the double oxido bridge that can be fitted with a simple Bleaney-Bowers S = 1/2 dimer model with g = 2.0703(8) and J = -1.83(2) cm-1. X-ray powder diffraction shows that 1 is obtained as a single crystalline phase. Hirshfeld surface analysis shows that intermolecular interactions in 1 are dominated by H-H, C-H, O-H and N-H interactions with percentages of 23.4, 15.8, 10.5 and 5.0 respectively.

Keywords: Copper(II) dimer, X-ray structure, Magnetic properties, Hirshfeld surface analysis