Vibrational spectroscopic and DFT calculation studies of a new organic–inorganic compound of bis (4-acetylanilinium) tetrachlorocadmiate (II)

Highlights: • The optimized molecular geometry of [C₈H₁₀NO]₂CdCl₄ compound was investigated. • Vibrational wavenumbers calculations based on DFT were reported and discussed. • The FT-IR spectra of [C₈H₁₀NO] ligand and its complex [C₈H₁₀NO]₂CdCl₄ were compared. The FT-IR and Raman vibrational spectra of bis (4-acetylanilinium) tetrachlorocadmiate (II) compound have been measured at room temperature by FT-infrared spectroscopy (4000–400 cm⁻¹) on polycrystalline samples, and by Raman spectroscopy (3600–30 cm⁻¹) on monocrystals. The structure of the [C₈H₁₀NO] ₂CdCl₄ formed by two cations [C₈H₁₀NO]⁺ of same type and one type of anion [CdCl₄]²⁻ was optimized by density functional theory (DFT) using the B3LYP method. The theoretical wavenumbers spectra were scaled by multiple scaling factors, yielding a good agreement between the experimentally recorded and the theoretically calculated values. Root mean square (rms) value was calculated and the small difference between experimental and calculated modes has been interpreted by intermolecular interactions in the crystal. The comparison between the [C₈H₉NO] ligand and the [C₈H₁₀NO]₂[CdCl₄] compound of the Raman spectra showed a decrease in the wavenumber of the bands assigned to the stretching vibration of (NH₃) group in the compound due to the effect of the protonation of the nitrogen.