Synthesis, structure, thermal and magnetic properties of new tetranuclear copper(II) complex supported by multidentate ligand and glutarate functionality

A new tetranuclear Cu(II) complex, [Cu(H 2 O) 4 ][Cu 4 (cpdp) 2 (glut)]Cl 2 middot6H 2 O ( 1 ) was successfully constructed by utilization of carboxylate-based multidentate ligand N,N '-bis[2-carboxybenzomethyl]- N,N 'bis[2-pyridylmethyl]-1,3-diaminopropan-2-ol (H 3 cpdp), in combination with glutarate (glut) and Cu(II) ions, and characterized systematically. Originally, the symmetrical flexible ligand cpdp 3 - is capable to bind two Cu(II) ions, leaving behind accessible binding sites for further coordination of exogenous glutarate anion which facilitates the assembly of two ligand-bound Cu(II) pairs. In MeOH/H 2 O, the reaction of CuCl 2 middot2H 2 O with H 3 cpdp and sodium glutarate in the presence of NaOH results in the formation of 1 . Complex 1 was characterized by different analytical techniques, including single crystal X-ray structure investigation. Analysis of single crystal X-ray structure shows that 1 is a self-assembled tetranuclear copper complex in which two dinuclear [Cu 2 (cpdp)] + species are exclusively bridged by one glutarate functionality through mu 4 : eta 1 : eta 1 : eta 1 : eta 1 manner, acting as a coligand. Thermoanalytical methods (TGA/DTA) were used to examine the thermal stability and it was observed that 1 is stable up to similar to 190 degrees C. Variable temperature (2-300 K) magnetic susceptibility studies show the weak antiferromagnetic interactions among the copper centers with the value of magnetic exchange coupling constant ( J ) of -0.5 cm -1 .(c) 2022 Elsevier B.V. All rights reserved.