Solvothermal synthesis, crystal structure, thermal, magnetic properties and DFT computations of a Ytterbium(III) complex derived from pyridine-2,6-dicarboxylic acid

A new ytterbium(III) complex, (DMAH₂)₃[Yb(Pydc)₃].4H₂O (1) {Pydc = Pyridine-2,6-dicarboxylate anion, DMAH₂ = Dimethylammonium} has been prepared under mild solvothermal conditions and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. The DMAH₂ molecules in 1, generated in situ from hydrolysis of N,N-dimethylformamide are responsible to assemble 2D coordination polymer through N-H···O and O-H···O hydrogen bonding. Magnetic susceptibility measurements indicate that the complex (1) obeys the Curie Weiss law and the overall magnetic behavior is typical for the presence of weak antiferromagnetic exchange coupling interactions. Theoretical data for geometrical parameters of complex 1 agree well with the experimental data. Large HOMO-LUMO energy gap of 4.33 eV has provided kinetic stability to the complex 1. NBO analysis reflects that intramolecular charge transfer occurred between ligand and metal orbitals with the highest stabilization energy of 1024.04 kcal/mol. The negative electrostatic potential at the nitrogen and dianionic pyridine-2,6-dicarboxylate regions confirms that these are dynamic locations for Yb(III) binding.