An investigation of a relatively rigid acyclic salamo-type ligand and its square planar Cu(II) complex

• Published in: Journal of coordination chemistry 2022-08, Vol.75 (15-16), p.2245-2257
• Main Authors: Li, Xun, Feng, Shan-Shan, Wei, Yu-Xin, Dong, Wen-Kui
• Format: Article
• Language: English
• Subjects: complex; crystal structure; Crystallography; Fluorescence; fluorescence property; Fourier transforms; Hirshfeld surface analysis; Hydrogen bonds; Hydroxyl groups; Infrared analysis; Infrared spectra; Ligands; Nitrogen atoms; Salamo-type ligand; Titration
• ISSN: 0095-8972; 1029-0389
• DOI: 10.1080/00958972.2022.2123738

A relatively rigid acyclic salamo-type ligand H 2 L and its square planar Cu(II) complex, [Cu(L)]·CH 3 OH, were synthesized and characterized by X-ray crystallography, as well as Fourier-transform infrared spectra, UV-Vis spectra, Hirshfeld surface analyses and DFT calculations. The ligand crystallizes in monoclinic space group P 2 1 /c and has pairs of intramolecular hydrogen bonds between the oxime nitrogen atoms and the hydroxyl groups. The Cu(II) complex crystallizes in the monoclinic space group P 2 1 /c. The Cu(II) ion is located in the N 2 O 2 cavity of the fully deprotonated salamo-type ligand (L) 2− unit, thus forming a four-coordinate distorted square planar geometry. At the same time, a belt-like, 2-D supramolecular structure is formed by the interaction of intermolecular hydrogen bonds, and the intermolecular interaction force is quantitatively analyzed by Hirshfeld surfaces. Significantly, fluorescence properties of the ligand and its Cu(II) complex were also studied. The coordination ratio of the Cu(II) complex was proved by UV-Vis and fluorescence titration experiments.