Synthesis, crystal structure, and magnetic properties of a new tetranuclear Cu(II) Schiff base compound

A new tetranuclear Cu(II) compound [Cu4(HL)2(L)2(ClO4)2] (1) was synthesized from the reaction of Cu(ClO4)2 · 6H2O with Schiff base ligand (H2L) condensed from ethanolamine with 2-hydroxyacetophenone. X-ray diffraction studies revealed that 1 is formed from the self-assembly of two dinuclear units [Cu2(HL)(L)(ClO4)] through the doubly phenoxo bridging. The variable temperature magnetic susceptibility measurements were performed between 300 K and 2 K and show χMT value for 1 at 300 K is 1.395 cm3 mol−1 K and fall to 0.0459 cm3 mol−1 K at 2 K. These values are smaller than that expected for tetranuclear copper (II) units, indicating antiferromagnetic coupling present in the compound. This result is also confirmed from the DFT calculations.