Structure, magnetic and luminescence properties of the lanthanide complexes Ln2(Salphen)3·H2O (Ln = Pr, Nd, Sm, Eu, Gd, Tb, Dy; H2Salphen = N,N′-bis(salicylidene)-1,2-phenylenediamine)

The series of compounds Ln2(Salphen)3(H2O) (1-Ln; Ln = Pr, Nd, Sm, Eu, Gd, Tb and Dy) was obtained. The crystal structure of 1-Nd was determined, and its isomorphism with the others was shown by powder XRD. These compounds possess dinuclear molecules with Ln–Ln distances of 3.965(30) Å (for 1-Nd). A systematic analysis of the magnetic properties of the complexes 1-Ln was performed in terms of the temperature dependences of the magnetic susceptibilities, revealing weak or, in the cases of the Eu and Dy complexes, negligible exchange interactions between the lanthanide ions. Compound 1-Eu displays characteristic Eu3+ photoluminescence at 77 K both in the solid state and in DMF/MeOH solution.