Syntheses, Structures, and Magnetism of Trinuclear Zn 2 Ln Complexes with 2,6‐Dipicolinoylbis( N , N ‐diethylthiourea)

The bifunctional ligand 2,6‐dipicolinoylbis( N , N ‐diethylthiourea) (H 2 L) readily reacts with mixtures of Zn(CH 3 COO) 2 and Ln Cl 3 in MeOH at ambient temperature with formation of trinuclear heterobimetallic complexes [Zn 2 Ln (L) 2 (OAc) 3 ] ( 1a – 1f ) ( Ln = Ce, Nd, Sm, Gd, Dy, Er). The X‐ray single‐crystal diffraction and structural studies of the complexes revealed their isostructural nature, in which two doubly‐charged ligands {L 2– } bind two Zn 2+ ions with the terminal acylthiourea sites and one Ln 3+ ion with the central 2,6‐pyridinedicarboxamide site. In the complexes, the coordination numbers of Ln III and Zn II ions are 9 and 5, respectively. Magnetic properties of the complexes were studied by temperature‐dependent dc magnetic measurements. The observed μ eff values at room temperature are all closed to the calculated values. Fitting χ M and M data of [Zn 2 Gd(L) 2 (OAc) 3 ] ( 1d ) shows a g iso value of 1.94.