Ab initio and DFT studies on structure, vibrational spectra of 4-tertbutyl- 1,3-thiazol-2-amine (BTA)

Theoretical studies have been carried out on 4-tert-butyl-1, 3-thiazol-2-amine (BTA) using both the B3LYP/6-311+G
and HF/6-311+G methods. The geometrical parameters and vibrational spectra of BTA have been calculated and analyzed. The calculated IR wavenumbers have been compared with the observed FTIR wavenumbers. The complete assignments
have been performed based on the potential energy distribution (PED) of the vibrational modes. The wavenumbers obtained from B3LYP method are in good agreement with the observed wavenumbers when compared to HF method. It has been
found that there is an excellent correlation with 0.999 regression coefficient between the experiment and calculated
vibrations. Thermal properties like rotational constants, zero point vibrational energies and nonlinear optical properties like dipole moment, hyperpolarizabilities, NBO analysis and the effect of temperature on various thermodynamic properties havebeen calculated and orted.