Binuclear Gadolinium Complex by One‐Pot Method: Structure and Magnetic Property

Abstract

Two butterfly‐like binuclear Gadolinium(III) (Gd) complex [Gd2(L1)2(H2L3)2(NO3)2] (1) and [Gd2(L2)2(H2L3)2(NO3)2] (2) were obtained by using 2‐hydroxybenzaldehyde or 2‐hydroxy‐1‐naphthaldehyde, 2‐aminophenol, pyridin‐2‐ylmethanamine and Gd(NO3)3·6H2O in CH3CN (H2L1 = (E)‐2‐((2‐hydroxybenzylidene)amino)phenol, H2L2 = (E)‐1‐(((2‐hydroxyphenyl)imino)methyl)naphthalen‐2‐ol, H2L3 = pyridin‐2‐ylmethanamine). Structural analysis suggests that all the ligands as protective units protect the central Gd(III) ions at the periphery. Magnetization studies exhibited magnetocaloric effect of 14.45 J·kg−1·K−1 at 4 K under ΔH = 7 T for complex 1 and 12.69 J·kg−1·K−1 at 2 K under ΔH = 7 T for complex 2. In complexes 1 and 2, although the coordination configurations are the same, the significant difference in MCE may be due to the adjustments of the peripheral ligands leading to changes in the coordination field strength. The electron affinity of the ligands can impact the interaction between the ligands and Gd(III) ions.