title: Theoretical investigations on the molecular structure, vibrational spectra, thermodynamics, HOMO-LUMO, NBO analyses and paramagnetic susceptibility properties of p-(p-hydroxyphenoxy)benzoic acid.
abstract: The experimental FT-IR (4000-400 cm(-1)) and FT-Raman (3500-100 cm(-1)) spectra of p-(p-hydroxyphenoxy) benzoic acid have been recorded. Quantum chemical calculations of energies, geometries, and vibrational wavenumbers of p-(p-hydroxyphenoxy) benzoic acid (PPHPBA) are carried out using HF and DFT/B3LYP methods with 6-311G (d,p) basis set. The optimized geometrical parameters obtained by B3LYP method show a good agreement with experimental data. The difference between the observed and scaled wave number values of most of the fundamentals is very small. The complete assignments were performed on the basis of the potential energy distribution (PED) of the vibrational modes calculated with scaled quantum mechanical method. The calculated HOMO and LUMO energies allow the calculation of atomic and molecular properties and they also show that charge transfer occurs in the molecule. A detailed molecular picture of PPHPBA and its intermolecular interactions were obtained from NBO analysis. The temperature dependence of various thermodynamic parameters was also studied. The paramagnetic behavior of the molecule under consideration has been investigated and the variation of paramagnetic susceptibility with temperature has been studied.
authors.affiliation: Centre for Research, Department of Physics, A A Government Arts College, Musiri 621 211, India. Electronic address: brsbala@rediffmail.com.
authors.forename: V
authors.initials: V
authors.lastname: Balachandran
authors.affiliation: P.G. & Research Department of Physics, Periyar EVR College (Autonomous), Tiruchirappalli 620 023, India.
authors.forename: S
authors.initials: S
authors.lastname: Lalitha
authors.affiliation: P.G. & Research Department of Physics, Periyar EVR College (Autonomous), Tiruchirappalli 620 023, India.
authors.forename: S
authors.initials: S
authors.lastname: Rajeswari
authors.affiliation: RD Foundation Group of Institutions, Kadrabad, Modinagar, Ghaziabad 201 204, India.
authors.forename: V K
authors.initials: VK
authors.lastname: Rastogi
mesh_terms: D001565:Benzoates / Q000737:chemistry*; D019817:Benzoic Acid / Q000737:chemistry*; D060328:Magnetic Phenomena; D008958:Models, Molecular; D008968:Molecular Conformation; D010647:Phenyl Ethers / Q000737:chemistry*; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics; D014732:Vibration
chemical_list: D001565:Benzoates; D010647:Phenyl Ethers; D019817:Benzoic Acid
keywords: DFT; HOMO–LUMO; NBO; Paramagnetic susceptibility; Thermodynamic analysis; p-(p-Hydroxyphenoxy)benzoic acid