A new family of dinuclear lanthanide complexes exhibiting luminescence, magnetic entropy changes and single molecule magnet behaviors

A new family of lanthanide complexes based on a tetrazole-1-acetate ligand and a 1,10-phenanthroline co-ligand were synthesized and characterized by IR spectroscopy, thermogravimetric analyses, powder X-ray diffraction and single-crystal X-ray diffraction, and their formula is [Ln(2)(mu-Cl)(2)(1-tza)(2)(phen)(4)](ClO4)(2) [Ln = Eu (1), Tb (2), Gd (3), Dy (4); 1-Htza = tetrazole-1-acetate, phen = 1,10-phenanthroline]. They show dinuclear structures bridged by mixed mu-COO(1-tza)(- )and mu-Cl-. The solid-state luminescence emission properties of 1 and 2 exhibit the characteristic emission bands of Ln cations with a lifetime of 1.49 ms and 0.20 ms, respectively. Magnetic studies reveal that 3 shows a magnetocaloric effect with -Delta S-max(m) = 18.5 J kg(-1) K-1 at 3 K for Delta H = 5 T and 4 displays a single-molecule magnet behaviour with U-eff of 15.19 K.

Automated summary

A new family of lanthanide complexes based on a tetrazole-1-acetate ligand and a 1,10-phenanthroline co-ligand was synthesized and characterized. These complexes exhibit dinuclear structures, solid-state luminescence emission properties, magnetocaloric effects, and single-molecule magnet behavior.