Exploring a more flexible N₂O₂-donor ligand and its octahedral tri-nuclear Co(II) and Ni(II) complexes

Abstract

Two new tri-nuclear Co(II) and Ni(II) complexes, [{Co(L)(μ-OAc)(EtOH)}₂Co]·2EtOH·2CH₂Cl₂ (1) and [{Ni(L)(μ-PhCOO)(MeOH)}₂Ni]·2CH₃OH·4H₂O (2), were synthesized by complexing H₂L (4-methylcoumarin-2,2′-[(propane-1,3-diyldioxy)bis(nitrilomethylidyne)]diphenol) with Co(OAc)₂⋅4H₂O and Ni(NO₃)₂·6H₂O, respectively, and characterized by chemical-physical characterization. For 1, the crystallographic analysis revealed there are three Co(II) ions, two completely deprotonated ligands (L^2–), two coordinated ethanol molecules and two bidentate bridging acetate groups (μ-OAc^-). Complex 2 is composed of three Ni(II) ions, two completely deprotonated L^2– ligands, two coordinated methanol molecules and two bidentate bridging benzoate groups (μ-PhCOO^–). The fluorescence properties of 1 and 2 were studied. The supramolecular structures of 1 and 2 are formed by intermolecular hydrogen bonds or π-related interactions. The important intermolecular interactions of H₂L and 1 and 2 were quantitatively determined by Hirshfeld surfaces analyses. In order to determine the kinetic stabilities of H₂L, 1 and 2, DFT calculations were performed at B3LYP/SDD level of theory.

Graphical Abstract

Keywords:

• Single crystal X-ray diffraction
• N2O2-donor ligand
• DFT
• property

Acknowledgment

This work was supported by the National Natural Science Foundation of China (21761018) and the Young Scholars Science Foundation of Lanzhou Jiaotong University (1200060810), two of which are gratefully acknowledged.

Supplementary data

CCDC − 2052720, 2052721 and 2052722 contains the supplementary crystallographic data for the ligand H₂L and its complexes 1 and 2. These data can be obtained free of charge via www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK (Telephone: [phone]; Fax: [phone]; or E-mail: [email protected]).

Disclosure statement

No potential conflict of interest was reported by the authors.