Spectroscopic, quantum chemical, QTAIM analysis, molecular dynamics simulation, docking studies and solvent effect of pyridin-2-yl oxyacetic acid herbicide and its derivatives

The density functional theory calculations and spectroscopic characterization (FTIR, FT- Raman, 1H, 13C NMR and ultraviolet–visible) of the herbicide compound Triclopyr (TCP) on monomeric and dimeric model is carried out. Its computational results are correlated with two pyridine derivative compounds FPA and FOP. The specific solvent effect of monomer with water complexes (TCPW, FPAW and FOPW) formed by hydrogen bonding interactions are investigated at the B3LYP 6-311G (d,p) level. Potential energy surface (PES) scanning of above compounds has been performed to discover the most stable conformer. The distribution of the vibrational bands are carried out with the help of normal coordinate analysis (NCA) and the resulting harmonic wavenumbers are scaled by using Wavenumber–Linear Scaling (WLS) method. The nature of inter and intramolecular hydrogen bonds are analyzed using NBO, QTAIM and Hirshfeld surface analysis. Furthermore herbicidal activity is confirmed on the compounds with molecular docking studies and molecular dynamic simulations (MDS).