Insights into crystal structures, supramolecular architectures and antioxidant activities of self‐assembled fluorescent hetero‐multinuclear [Cu (II)‐Ln (III)] (Ln = La, Ce, Pr and Nd) salamo‐like complexes

• Published in: Applied organometallic chemistry 2020-12, Vol.34 (12), p.n/a
• Main Authors: Pu, Lu‐Mei, An, Xiao‐Xin, Liu, Chang, Long, Hai‐Tao, Zhao, Li
• Format: Article
• Language: English
• Subjects: Antioxidants; Cerium; Chemistry; Crystal structure; Fluorescence; hetero‐multinuclear 3d‐4f complex; Imines; In vitro methods and tests; Lanthanum; Praseodymium; property; Salamo‐like bisoxime ligand; Scavenging; synthesis
• ISSN: 0268-2605; 1099-0739
• DOI: 10.1002/aoc.5980

Newly designed hetero‐dinuclear 3d–4f complex [Cu(L)La (NO3)2(μ‐NO3)(H2O)]·EtOH (1), hetero‐tetranuclear 3d–4f complex [Cu(L)Ce (NO3)2(μ‐NO3)(OAc)2]2·MeOH (2) and hetero‐multinuclear 3d–4f complexes [{Cu(L)Ln (NO3)3}2][Cu(L)Ln (NO3)3]2 (Ln = Pr (3) and Nd = (4)) have been self‐assembled from the reaction of Cu (OAc)2·H2O, Ln (NO3)3·6H2O (Ln = La, Ce, Pr and Nd) with an unsymmetric salamo‐like bisoxime ligand H2L (6‐Methoxy‐6′‐ethoxy‐2,2′‐[ethylenedioxybis (nitrilomethylidyne)]diphenol) based on a Schiff base condensation of 2‐[O‐(1‐ethoxyamide)]oxime‐6‐methoxyphenol and 3‐ethoxysalicylaldehyde. The structures of complexes 1–4 were characterized by elemental analyses, PXRD analyses, IR, UV–Vis spectra, and single‐crystal X‐ray analyses. In addition, the supramolecular interactions and fluorescence properties of complexes 1–4 are discussed in detail. Moreover, the antioxidant activities of the complexes 1–4 were determined by superoxide radical‐scavenging method in vitro, which indicates that the complexes 1–4 all show potential antioxidant properties. Four new 3d–4f complexes have been self‐assembled from the reaction of Cu(OAc)2·H2O, Ln(NO3)3·6H2O (Ln = La, Ce, Pr and Nd) and an salamo‐type bisoxime ligand H2L, respectively. The structures of complexes 1–4 were characterized by elemental, PXRD, spectra and single‐crystal X‐ray analyses. The supramolecular interactions and fluorescence properties are discussed. The antioxidant activity of the complexes 1–4 were determined by superoxide radical‐scavenging method in vitro, which indicates that the complexes 1–4 all show potential antioxidant properties.