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.
Acknowledgments
The authors thank the Head, Department of Chemistry, Banaras Hindu University, Varanasi, for providing laboratory facilities. The authors are grateful to Mr Suryanarayan Das and Mr Kranti Kumar Sharma for their help in the magnetic data recording. Thanks are also due to I.T.(B.H.U.) for powder X-ray data, CDRI, Lucknow for FAB-MS, SAIF IIT, Mumbai for TGA analysis, Mr Satish Tiwari for CHN analyses and Mr V.N. Pandey for IR and electronic spectra recording. One of the authors (KRR) thanks BHU for research scholarship.