Crystal structures, DFT calculations and Hirshfeld surface analyses of three new cobalt(III) Schiff base complexes derived from meso-1,2-diphenyl-1,2-ethylenediamine

• Three new Co(III) Schiff base complexes where synthesized.
• Crystal structures of the complexes were obtained.
• Solid state intermolecular interactions were studied by Hirshfeld surface analysis.
• DFT calculations were performed to study optimized structures.
• IR and UV–Vis spectra were also studied by DFT calculations.

Three new Cobalt(III) Schiff base complexes were synthesized and characterized by spectroscopic methods and x-ray crystallography. The DFT optimized structures of the complexes agreed well with the corresponding x-ray structures. According to the calculated vibrational normal modes, the observed signals in the IR spectra of the complexes were assigned. The experimental UV–Vis spectra of the complexes were also discussed considering the calculated excited states and molecular orbitals. Hirshfeld surface analysis was carried out to study the inter-contact interactions in these complexes. These studies provided comprehensive description of such inter-contact interactions by means of an appealing graphical approach using 3D Hirshfeld surfaces and 2D fingerprint plots derived from the surfaces. It indicated the dominant role of various hydrogen intermolecular interactions such as H⋯H (above 60%), C⋯H/H⋯C (near 15%–20%), O⋯H/H⋯O (about 16% or 17% for structures with counter ion ClO4−) and H⋯F (17% for structure with counter ion PF6−) contacts into the crystal packing which are discussed in details.

Three new Co(III) Schiff base complexes were synthesized and characterized by X-ray crystallography. Intermolecular interactions in the solid states were studied by Hirshfeld surface analysis. Optimized structures as well as IR and UV–Vis spectra were studied by DFT calculations.Figure optionsDownload as PowerPoint slide