Experimental and theoretical approaches to structural, spectroscopic, electronic and NLO properties of a herbicide fentrazamide

A herbicide fentrazamide which is a chemical class tetrazolinone derivative was studied by using FT-IR, ¹H- and ¹³C-NMR (in chloroform-d) and UV–Vis. (in acetonitrile) spectroscopic techniques. To support the experimental spectral data and to uncover electronic structure properties, the compound was theoretically modeled at the DFT/B3LYP method with the 6–311++G(d,p) basis set. The molecular structural parameters (bond lengths and angles) and harmonic vibrational wavenumbers were obtained in the gas phase at the ground state of the compound. Theoretical NMR chemical shifts were investigated with GIAO method. The intra-molecular electronic transition features were detailed with the help of the computational UV–Vis. spectral and HOMO-LUMO analyses. The presence and species of the intra-molecular hyperconjugative interactions were studied by NBO study. Moreover, the natural and Mulliken atomic charges were determined with the computational method. The electrophilic and nucleophilic reactive attack sites of fentrazamide were determined with the theoretical simulation of its MEPS surface map. To gain insight into the NLO behavior of fentrazamide, the polarizability (α) and hyperpolarizability (β for first-order and γ for second-order) values were calculated at the static and dynamic (ω = 532 nm and 1064 nm) states. The thermodynamic profile of the compound was theoretically analyzed.