Molecular structure, electronic properties, NLO, NBO analysis and spectroscopic characterization of Gabapentin with experimental (FT-IR and FT-Raman) techniques and quantum chemical calculations
Küçük Resim Yok
Tarih
2013
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Gabapentin (GP), structurally related to the neurotransmitter GABA (gamma-aminobutyric acid), mimics the activity of GABA and is also widely used in neurology for the treatment of peripheral neuropathic pain. It exists in zwitterionic form in solid state. The present communication deals with the quantum chemical calculations of energies, geometrical structure and vibrational wavenumbers of GP using density functional (DFT/B3LYP) method with 6-311++G(d,p) basis set. In view of the fact that amino acids exist as zwitterions as well as in the neutral form depending on the environment (solvent, pH, etc.), molecular properties of both the zwitterionic and neutral form of GP have been analyzed. The fundamental vibrational wavenumbers as well as their intensities were calculated and compared with experimental FT-IR and FT-Raman spectra. The fundamental assignments were done on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. The electric dipole moment, polarizability and the first hyperpolarizability values of the GP have been calculated at the same level of theory and basis set. The nonlinear optical (NLO) behavior of zwitterionic and neutral form has been compared. Stability of the molecule arising from hyper-conjugative interactions and charge delocalization has been analyzed using natural bond orbital analysis. Ultraviolet-visible (UV-Vis) spectrum of the title molecule has also been calculated using TD-DFT method. The thermodynamic properties of both the zwitterionic and neutral form of GP at different temperatures have been calculated. © 2013 Elsevier B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
DFT, FT-IR and FT-Raman, Gabapentin, NBO, NLO, DFT, FT-Raman, Gabapentin, NBO, NLO, Amino acids, Electronic properties, Molecules, Quantum chemistry, Quantum theory, Chemical bonds, 4 aminobutyric acid, amine, analgesic agent, cyclohexanecarboxylic acid derivative, gabapentin, article, chemical structure, chemistry, infrared spectroscopy, quantum theory, Raman spectrometry, Amines, Analgesics, Cyclohexanecarboxylic Acids, gamma-Aminobutyric Acid, Models, Molecular, Quantum Theory, Spectroscopy, Fourier Transform Infrared, Spectrum Analysis, Raman, DFT, FT-IR and FT-Raman, Gabapentin, NBO, NLO, DFT, FT-Raman, Gabapentin, NBO, NLO, Amino acids, Electronic properties, Molecules, Quantum chemistry, Quantum theory, Chemical bonds, 4 aminobutyric acid, amine, analgesic agent, cyclohexanecarboxylic acid derivative, gabapentin, article, chemical structure, chemistry, infrared spectroscopy, quantum theory, Raman spectrometry, Amines, Analgesics, Cyclohexanecarboxylic Acids, gamma-Aminobutyric Acid, Models, Molecular, Quantum Theory, Spectroscopy, Fourier Transform Infrared, Spectrum Analysis, Raman
Kaynak
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
109
