Structural confirmation and spectroscopic signature of N-Allyl-2‑hydroxy-5-methyl-3-oxo-2, 3-dihydrobenzofuran-2-carboxamide and its monohydrate cluster

Abstract

We performed optimization of a bio-relevant molecule N-Allyl-2‑hydroxy-5-methyl-3-oxo-2, 3-dihydrobenzofuran-2-carboxamide and its monohydrate cluster in the isolated form. Potential energy scanning for the target molecule was carried out. Consequently, three stable conformers were obtained. The effect of interfusion of a water molecule on energy and vibrational modes of the target molecule was also investigated in the most stable conformer. The electronic structures and vibrational spectra of all the three conformers were computed. The FTIR spectrum of the target molecule was recorded at the spectral width of 4000–400cm−1 which was compared with the theoretically computed spectrum of the most stable conformer. We have computed Raman spectra of all the conformers. All theoretical calculations performed in this investigation were done at DFT/B3LYP level of theory. The standard normal coordinate analysis (NCA) method was used to calculate the potential energy distributions of normal modes of the target molecule and its monohydrate cluster. Moreover, the NBO calculations for the target molecule and its monohydrate cluster were done to determine electronic structures, bond energies, occupancies, HOMO-LUMO and hyper-conjugative interaction energies of donor-acceptor interactions. The enthalpy of formation showed that the formation of the monohydrated cluster is of an exothermic nature.