Two isostructural layered lanthanide(III) complexes. Syntheses, structures, magnetic and luminescent properties

Two N'‐(2‐hydroxybenzylidene)pyridine N-oxide-carbohydrazide (H${}_3$L)-based coordination complexes with the formula [Ln${}_2$(DMF)${}_2$(OAc)${}_2$(HL)${}_2$]${}_n$ (Ln = Dy for 1 and Eu for 2) were solvothermally synthesized. Crystal structures, thermal stabilities, magnetic and luminescent properties of the two complexes were fully investigated. Both complexes are isomorphic two-dimensional layers with centrosymmetric {Ln${}_2$} subunits extended by doubly deprotonated HL${}^{2-}$ connectors. Complex 1 with highly anisotropic Dy${}^{III}$ spin exhibits slightly frequency-dependent magnetic relaxations under zero dc field with an effective energy barrier of ca. 6.84 K. Eu${}^{III}$-based complex 2 displays only one weak fluorescent emission around 532 nm with the absence of characteristic emission of Eu${}^{III}$ ion. These results provide helpful hints of the hydrazide Schiff-functionalized organic ligands on the function modulations of the resulting Ln complexes. (© 2020 WILEY‐VCH Verlag GmbH and Co. KGaA, Weinheim)