Synthesis, structures, and computational studies of methoxydisubstituted bis(salamo)-type homopolynuclear Cu(II) and Co(II) complexes

Abstract

Centrosymmetric homopolynuclear Cu(II) and Co(II) chelated complexes, [Cu₂(L)(H₂O)₂] (1) and [Co₄(L)(μ-OAc)₂(CH₃OH)₄(OA_C)₂]⋅2CH₂Cl₂ (2), were synthesized using a new symmetrical methoxy-disubstituted bis(salamo)-type ligand, H₄L, with Cu(II) and Co(II) salts in organic solvents. Complexes 1 and 2 were structurally characterized by single-crystal X-ray crystallography. The results indicated that 1 is a five-coordinate dinuclear structure containing Cu(II) and 2 is a tetranuclear Co(II) complex with two distinct six-coordinate environments. Furthermore, 1 and 2 pack into three-dimensional and two-dimensional extended networks, respectively. The UV–Vis spectra, IR spectra, and Hirshfeld surface analyses of the complexes were carried out to further characterize the coordination between H₄L and the metal(II) ions. Fluorescence methods were used to interrogate the coordination, where changes in emission with varied amounts of ligand supported solution-phase coordination ratios of H₄L with Cu(II) ion of 1:2 and with Co(II) ion of 1:4, respectively.

Keywords:

• Complex
• crystal structure
• rigid bis(salamo) type ligand
• synthesis
• fluorescence property

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Science and Technology Program of Gansu Province (21YF5GA057) and the Basic Research Top Talent Training Program of Lanzhou Jiaotong University (2022JC09), two of which are gratefully acknowledged.