Structural and theoretical insights towards the understanding of the effect on the conformation of ligand by complexation process

•Synthesis of novel ligand and its corresponding palladium complex.•Conformational changes of the ligand due to the approach of the palladium metal is explored.•Hirshfeld surface analysis was used to analyze and quantify the intermolecular interactions.•The chemical reactivity was analyzed by MEP, HOMO-LUMO and NBO. The ligand and the palladium complex were synthesized and characterized by the single crystal X-ray diffraction method. The Hirshfeld surface analysis quantified the intermolecular interactions stabilizing the crystal packing in both compounds. DFT (density functional theory) calculations were used to optimize the geometric structures and calculate the electronic properties of the synthesized compounds. The ligand and complex's electronic structure and UV-Vis spectrum are interpreted by DFT and TD-DFT (time dependent-density functional theory) calculations. The NBO (natural bond orbital) analysis was employed to study the origin and nature of the hyperconjugation interactions. The intramolecular interaction energies associated with different topologies were calculated using the QTAIM (Quantum Theory of Atoms in Molecules), and the non-covalent interactions revealed the type and nature of the interactions exhibited by the compound. The structural and theoretical analysis revealed the change in the properties of the ligand due to the complexation process.