Structural and spectral speciation on methyl 2-(3-(furan-2-carbonyl)thioureido)benzoate: A comparative experimental and theoretical study

A new thiourea derivative, methyl 2-(3-(furan-2-carbonyl)thioureido)benzoate (MFCTB) is synthesized and characterized by elemental analysis, FT-IR, FT-Raman, electronic, NMR and single crystal X-ray diffraction study. The compound crystallizes in the orthorhombic space group Pbca with Z = 8. The molecular geometry was also optimized using density functional theory (DFT) employing B3LYP exchange correlation with the 6-311G(d,p) basis set. The theoretically calculated bond parameters are in good agreement with the experimentally obtained results as reflected by CS 1.673 (1.668), CO 1.221 (1.228) Å, bond distances. The infrared spectra of the compound showed four significant vibrations δ(NH) (I), ν(CN) (II and III) and ν(CS) (IV) around 1500, 1300, 1100 and 750 cm−1 and matched well with DFT calculated values. The 1H NMR spectrum of the compound shows mainly three peaks SCNH, OCNH and OCOCH3 at 13.25 (12.94); 9.25 (8.99) and 3.94 (3.81) ppm, respectively and displayed good correlation while its 13C NMR spectrum showed some differences with its theoretical counterpart. Also electronic spectrum of the compound which comprises mainly two bands around 289 and 325 was compared with the theoretical spectrum obtained from time-dependent (TD) DFT and a good agreement is observed. The molecular electrostatic potential (MEP) map shows the negative potential sites are on oxygen, sulphur and nitrogen atoms and the positive potential sites are around the hydrogen atoms.