Synthesis, crystal structure, fluorescence properties and theoretical calculations of heterobimetallic 3d-4f complex with a flexible bis(salamo)-type ligand

A new heterobimetallic 3d-4f [Cu(II)(2) Pr(III)] complex [Cu2Pr(L)(eta(2)-NO3)(3)(EtOH)(2)]center dot 2EtOH with a symmetric flexible bis(salamo)-type ligand, (1E,1'E)-2,3-dihydroxynaphthalene-1,4-dicarbaldehyde O,O-di(3-((((E)-3-ethoxy-2-hydroxybenzylidene)amino)oxy)propyl)dioxime (H4L), has been synthesized and characterized structurally. Single crystal X-ray diffraction analysis showed that the ligand was fasten by different metal ions to form a hetero-trinuclear complex with C-shaped structure, where two N2O2-donors of the completely deprotonated ligand (L)(4-) unit and two oxygen atoms from two ethanol molecules coordinate with Cu(II) atoms (Cu1, Cu2), respectively, to form two five-coordinated square pyramid geometries. Meanwhile, where the O-6 cavity coordination sphere of the ligand (L)(4-) unit and six oxygen atoms from three nitrate groups coordinate with the Pr(III) atom together to form a twelve-coordinated icosahedron. Due to the Cu(II) atom in the O-6 cavity was replaced by the Pr(III) atom, it shows that the hetero-trinuclear complex after self-assembly is more stable than the homo-trinuclear complex. At the same time, through UV-Vis titration spectrometric analysis, we can observed that the hetero-trinuclear [Cu(II)(2)Pr(III)] complex is obtained by 1 equiv. Pr(NO3)(3)center dot 5H(2)O and 2 equiv. Cu(NO3)(2)center dot 3H(2)O and 1 equiv. H4L. Significantly, fluorescence properties and Hirshfeld surfaces analyses of the [Cu(II)(2)Pr(III)] complex was also studied. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

A new heterobimetallic complex has been synthesized and characterized. The complex exhibits a stable structure and good thermal stability, providing a reference for future material research.