DFT simulations and vibrational spectra of 2-amino-2-methyl-1,3-propanediol

• The solid phase FTIR and FT-Raman spectra of AMPD were recorded and analyzed.
• The complete vibrational assignment and spectroscopic analysis is performed.
• UV and NMR spectral analysis were carried out.
• Calculated HOMO and LUMO energies shows that charge transfer occur within molecule.
• The first-order hyperpolarizability of AMPD was computed using DFT calculations.

The FTIR and FT-Raman spectra of 2-amino-2-methyl-1,3-propanediol were recorded in the regions 4000–400 cm−1 and 4000–50 cm−1 respectively. The structural and spectroscopic data of the molecule in the ground state were calculated using Hartee-Fock and density functional method (B3LYP) with the augmented-correlation consistent-polarized valence double zeta (aug-cc-pVDZ) basis set. The most stable conformer was optimized and the structural and vibrational parameters were determined based on this. The complete assignments were performed on the basis of the Potential Energy Distribution (PED) of the vibrational modes, calculated using Vibrational Energy Distribution Analysis (VEDA) 4 program. With the observed FTIR and FT-Raman data, a complete vibrational assignment and analysis of the fundamental modes of the compound were carried out. Thermodynamic properties and Mulliken charges were calculated using both Hartee-Fock and density functional method using the aug-cc-pVDZ basis set and compared. The calculated HOMO-LUMO energy gap revealed that charge transfer occurs within the molecule. 1H and 13C NMR chemical shifts of the molecule were calculated using Gauge-Independent Atomic Orbital (GIAO) method and were compared with experimental results.

The theoretical calculation shows 2-amino-2-methyl-1,3-propanediol has a structure of C1 point group has 18 atoms and 48 normal modes of vibrations. The computations were performed at RHF/aug-cc-pVDZ and B3LYP/aug-cc-pVDZ levels to obtain the optimized geometrical parameters, vibrational wavenumbers of the normal modes, IR intensity, atomic charges and thermodynamical parameters of the compound.Figure optionsDownload as PowerPoint slide