Investigation of spectral and structural properties of a coordination compound with phthalic acid: DFT and molecular docking studies

The mixed-ligand coordination compound, [Cu(Hpht)2(na)2(H2O)] (1) (Hpht− = monoanion of phthalic acid and na = nicotinamide), was investigated by focusing on its supramolecular architecture. Structural properties of the complex were characterized by elemental analysis, XRD, spectroscopic methods and thermogravimetric analysis. The complex was connected by hydrogen bonds to form 3-D supramolecular structures. The FT-IR study of the complex was carried out in the middle-IR region focusing on the characteristic vibrations of the free ligands and the complex. Scaled theoretical vibrational frequencies were compared with experimental values. The magnetic properties of the complex were investigated by electron paramagnetic resonance (EPR) spectroscopy. Further ultra-violet (UV-vis) spectral analysis and thermogravimetric analysis were performed to understand optical and thermal properties. The molecular structure was theoretically optimized using DFT/B3LYP/LanL2DZ methods for ground state. Scaled theoretical results of molecular structure, FT-IR and UV-Vis spectra were compared with experimental results. The optimized complex was docked to B-DNA (ID: 1BNA).