Investigating into crystal structures and supramolecular architectures of four newly synthesized hetero-octanuclear [CuII4-LnIII4] (Ln = Sm, Eu, Tb and Dy) complexes produced by a hexadentate bisoxime chelate ligand

Abstract

Four unprecedented 3d-4f hetero-octanuclear family-type complexes [{Cu(L)Ln(NO3)3}2][Cu(L)Ln(NO3)3]2 (Ln = Sm (1), Eu (2), Tb (3) and Dy (4)) were synthesized by an unsymmetric single salamo-like ligand H2L (6-Methoxy-6′-ethoxy-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol) with Cu(OAc)2·H2O and Ln(NO3)3·6H2O (Ln = Sm, Eu, Tb and Dy), respectively. X-ray crystallography revealed that each hetero-octanuclear 3d-4f metal complexes [{Cu(L)Ln(NO3)3}2][Cu(L)Ln(NO3)3]2 contains one neutral dimer [{Cu(L)Ln(NO3)3}2] unit and two independent [Cu(L)Ln(NO3)3] units. At the same time, the four Cu(II) atoms of the complexes 1–4 have four- and five-coordinated configurations, while the four Ln(III) atoms have only one configuration, all of which are ten-coordinated. The structures of the four complexes 1–4 were characterized via elemental analyses, PXRD, FT-IR and UV–Vis spectroscopy. In addition, while studying the crystal structure, the supramolecular interactions and spectral properties of the complexes 1–4 were studied in detail.