The template synthesis and crystal and molecular structure of a sexidentate Schiff-base macrocyclic complex of samarium(III), [Sm(C18H18N6)(NO3)(OH)(H2O)]NO3·2MeOH

Abstract

The template condensation of 2,6-pyridinedicarbaldehyde with ethylenediamine in the presence of Sm(NO₃)₃ gave a complex formulated as [Sm(C₁₈H₂₀N₆O)(NO₃)₃]. The complex was recrystallised from water and the X-ray crystal structure determined by the heavy-atom method and refined by least squares to a final R value of 0.073. The recrystallised compound can be formulated as the title complex. The Sm³⁺ cation is enclosed in the cyclic ligand and bonded to its six N atoms as well as to a bidentate NO₃^– anion, to one OH^– anion, and to a water molecule: Some O ⋯ O contact distances can be ascribed to hydrogen bonds; the clathrate solvent molecules are disordered.