Molecular structure analysis and spectroscopic characterization of 9-methoxy-2H-furo[3,2-g]chromen-2-one with experimental (FT-IR and FT-Raman) techniques and quantum chemical calculations

• FT-IR and FT-Raman spectra of 9M2HFC in the solid phase were recorded and analyzed.
• The PED calculation provides a strong support for the frequency assignment.
• The NBO analysis explains the intra molecular hydrogen bonding.
• The first order hyperpolarizability and HOMO, LUMO energy gap were theoretically predicted.

Experimental and theoretical investigations on the molecular structure, electronic and vibrational characteristics of 9-methoxy-2H-furo[3,2-g]chromen-2-one (9M2HFC) were presented. The vibrational frequencies were obtained by DFT/B3LYP calculations employing 6-311++G(d,p) basis set, were compared with experimental FT-IR and FT-Raman spectral data. The FT-IR spectrum (4000–400 cm−1) and FT-Raman spectrum (4000–100 cm−1) in solid phase were recorded for 9M2HFC. The geometry of the title compound was fully optimized. Quantum chemical calculations of the equilibrium geometry, the complete vibrational assignments of wavenumbers using potential energy distribution (PED) calculated with scaled quantum mechanics infrared intensities, Raman activities of the title molecule was reported. HOMO–LUMO energies, molecular electrostatic potential, Mulliken population analysis on atomic charges, natural bond orbital (NBO) analysis, non linear optical behavior in terms of first order hyperpolarizability, and thermodynamic properties of the title molecule were carried out. Finally, simulated FT-IR and FT-Raman spectra showed good agreement with the observed spectra.

In this work, the vibrational spectral analysis was carried out using FT-IR and FT-Raman spectroscopy for 9-methoxy-2H-furo[3,2-g]chromen-2-one. The computations were performed at DFT theory to get optimized geometry and vibrational wave numbers of the normal modes of the title compound. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution (PED). The HOMO and LUMO energies, NBO analysis, were carried out.Figure optionsDownload as PowerPoint slide