In this paper, ab initio Hartree-Fock (HF) and Density Functional Theory (DFT), using Becke-3–
Lee–Yang–Parr (B3LYP) hybrid density functional, calculations have been performed to characterize the ground
state geometrical energy, the dipole moment (μ), polarizability (α), the hyperpolarizability (β) of picolinic acid
(PA), picolinamide (PAA) and picolinic acid hydrazide (PAH) molecules using the 6-311++G (d, p) basis set.
The 1H and 13C NMR chemical shifts were calculated by GIAO approach by using B3LYP/6-311+G (2d, p) and
HF/6-31G (d) level of theory. Also, EHOMO (the highest occupied molecular orbital energy), ELUMO (the lowest
unoccupied molecular orbital energy), HOMO-LUMO energy gap (ΔEg), the dipole moment (μ), polarizability (α)
and the hyperpolarizability (β) are investigated as a function of the torsional angle, for each molecule. In addition,
the trends in the calculated torsional potentials, barrier heights and energy differences between conformers are
discussed. The trans-conformers of the studied molecules were found to be most stable among their conformers.
The potential barrier height of cis- conformers are at 13.24, 10.69, and 9.56 with DFT/B3LYP level of the theory
6-311++G (d, p) basis set and at the HF/6-311++ G (d, p) 13.53, 10.94, and 10.55 kcal/mol, respectively. The
structural parameters of the studied molecule compared with the data given in the literature.
Primary Language | Turkish |
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Subjects | Metrology, Applied and Industrial Physics |
Journal Section | Fizik / Physics |
Authors | |
Publication Date | March 31, 2018 |
Submission Date | July 28, 2017 |
Acceptance Date | October 25, 2017 |
Published in Issue | Year 2018 |