New homo- and hetero-bimetallic assemblies based on 2,5-bis(4-carboxyphenylamino)-3,6-dichloro-1,4-benzoquinone: synthesis, characterization, and magnetic properties

Abstract

Synthesis, characterization, and magnetic properties of a new series of dinuclear compounds MIIM′IIL2(H2O)4 (where MII, M′II = Mn (1), Ni (2), Cu (3) and MII = Cu, M′II = Co (4), Ni (5); LH2 = 2,5-bis(4-carboxyphenylamino)-3,6-dichloro-1,4-benzoquinone) are reported. These complexes were characterized by elemental analyses, FAB mass spectra, thermogravimetric analysis, spectroscopic techniques (infrared, NMR, UV-Vis), and powder XRD studies. Magnetic properties investigated by SQUID magnetometer show antiferromagnetic coupling between the metal centers connected by the extensive π-delocalized ligand. Magnetic coupling constants (J) ranging from −1.01 to −3.01 cm−1 based on the Hamiltonian H = −2JS i S j have been obtained. The optimized geometry of the ligand derived from DFT is also reported.