Experimental (FT-IR, FT-Raman, NMR) and theoretical spectroscopic properties of intermolecular hydrogen bonded 1-acetyl-2-thiohydantoin polymorphs.

In this work, use of FT-Raman, FT-IR and (13)C NMR spectroscopies have been made for the full characterization of 1-acetyl-2-thiohydantoin (ACTH). A detailed interpretation of the vibrational spectra was carried out with the aid of normal coordinate analysis using single scaling factor. Our results support the hydrogen bonding pattern proposed in the reported crystalline structure. Good reproduction of experimental values is obtained and % error is small in majority of the cases. Isotropic chemical shifts were calculated using gauge-invariant atomic orbital (GIAO) along with several thermodynamic parameters.