A homochiral Nickel(II) complex [Ni(P'N)2]Cl2: Synthesis, characterization, crystal structure, luminescence, DFT and Hirshfeld surface studies

•The homochiral ligand (S,S)-NH2CHPhCHPhPPh2 is used to prepare the complex [Ni(P'N)2]Cl2.•The properties of the complex are analyzed with data from single crystal X-ray diffraction, NMR,.•IR, UV–vis and fluorescence spectroscopy.•Complementary data are provided by density functional theory and Hirshfeld surface analysis.•calculations. A new complex ([Ni(P'N)2]Cl2) is synthesized from an anhydrous NiCl2 and a bidentate P'N (S,S)-NH2CHPhCHPhPPh2) ligand with an enantiopure ethylene backbone. The solubility of the complex in methanol aids its crystallization by slow evaporation. A single crystal X-ray diffraction study of the complex reveals a distorted square planar geometry with the phosphinyl groups coordinated in a cis(P,P) configuration. This imposes steric effects that influence the crystal packing of the complex in an orthorhombic unit cell. The complex possesses characteristic metal to ligand charge transfer (MLCT) transition in the UV region with a peak absorption at 294 nm corresponding to 4.22 eV, which correlates with 4.24 eV derived from the DFT calculation of the energy band gap between the highest molecular orbital (HOMO:7.39 eV) and lowest unoccupied molecular orbital (LUMO:3.15 eV) of the complex. With an excitation wavelength of 415 nm (3.00 eV), the complex emits photons with wavelength 488 nm (2.54 eV) in the blue region of the visible spectrum. The circular dichroism spectrum has multiple peaks in the UV region mainly associated with transitions within the chiral array of phenyl groups. The bond lengths, bond angles, and vibrational bands obtained by simulation of the optimized structure of the complex provide analytical details that strongly correlate with the experimental data with adjusted R2 of 0.9826 (bond lengths), 0.9911 (bond angles) and 0.9983 (vibrational bands). The Hirshfeld surface analysis shows that H…H and C…H interactions between phenyl rings of the cations contribute significantly to the crystal packing of the complex. [Display omitted]