Supramolecular architectures of mononuclear nickel(II) and homobinuclear copper(II) complexes square with the 5,5'dimethyl-2,2'-bipyridine ligand: Syntheses, Crystal structures and Hirshfeld surface analyses

Wassim Maalej (1) , Rim Jaballi (1) , Asma Ben Rached (1) , Philippe Guionneau (2) , Nathalie Daro (2) , Zakaria Elaoud (1)

1 Laboratory of Physical Chemistry of the Solid State
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Two new compounds based on one mononuclear nickel(II) and one homobinuclear copper(II) complexes respectively and of genrela formula [Ni(dmbpy)2(CH3COO)]ClO4 (1) and [Cu2(dmbpy)4(CH3COO)3]ClO4 (2) with dmbpy = 5,5'-dimethyl-2,2'bipyridine, were synthesized by hydrothermal treatment. Both were influenced by the coordinated acetate ion molecule. The crystal and molecular structures of (1) and (2) were determined by single crystal X-ray diffraction method and both compounds were additionnally characterized by means of elemental and thermogravimetric analysis, FT-IR spectroscopy, powder X-ray diffraction and UV-visible. The mononuclear complex (1) shows a distorted octahedral geometry around the metal ion. On the other hand, the copper(II) compound crystallizes as an homobinuclear system, in which each of the metal ions is located into the N2O3 coordination spheres adopting a distorted square pyramidal geometry. In (2) the intramolecular distance between two copper atoms is of the order of Cu1-Cu2 = 3.38 (2) Å. In both crystal packing of these two complexes, H-bonding,π⋯π, and C-H⋯π interactions are operative in forming supramolecular motifs. Complex (1) displays two 1-D chains that lead to form R 8 8 (42) ring motifs, repetition of which generates a 2-D supramolecular network. These chains interacts with the neighbouring ones via intermolecular C-H•••π and π•••π stacking interactions, leading to the formation of a 3D-stacking network (2-D+1-D→3-D). Formation of a 2-D supramolecular sheet in the solid state structure of (2) is facilitated by the C-H⋯O, C-H⋯π and π⋯π interactions (1-D+1-D→2-D). Hirshfeld surface analysis and theoretical calculations were carried out on the two compounds. The results clearly show that C-H•••O, C-H••• π and π•••π stacking interactions play a paramount role in the stabilization of the supramolecular architecture of (1) and (2). In addition, adsorption spectra reveal their semiconductive nature (4.19 eV for 1• and 4.43 eV for 2).

Mots clés: Hydrothermal synthesis; Organic-inorganic; Crystal structure; Optical properties; Hirshfeld surface; Semiconductor material

Domaines: Matériaux

Wassim Maalej, Rim Jaballi, Asma Ben Rached, Philippe Guionneau, Nathalie Daro, et al.. Supramolecular architectures of mononuclear nickel(II) and homobinuclear copper(II) complexes square with the 5,5'dimethyl-2,2'-bipyridine ligand: Syntheses, Crystal structures and Hirshfeld surface analyses. Journal of Molecular Structure, 2022, 150 (Part 2), 131728 (16 p.). ⟨10.1016/j.molstruc.2021.131728⟩. ⟨hal-03425004⟩