title: Structural and vibrational spectroscopic studies on charge transfer and ionic hydrogen bonding interactions of melaminium benzoate dihydrate.
abstract: Single crystals of melaminium benzoate dihydrate (MBDH) have been grown from aqueous solution by the slow solvent evaporation method at room temperature. Crystalline nature of the grown crystal has been confirmed by X-ray powder diffraction studies. The optimized geometry, frequency and intensity of the vibrational bands of MBDH were obtained by the Hartree-Fock and density functional theory using B3LYP/cam-B3LYP with 6-311++G(d,p) basis set. The harmonic vibrational frequencies were calculated and the scaled values have been compared with the experimental FT-IR and FT-Raman spectral values. The obtained vibrational wavenumbers and optimized geometric parameters are found to be in good agreement with the experimental data. UV-Visible spectrum was recorded in the region 200-400 nm and the electronic properties, HOMO-LUMO energies and other related electronic parameters are calculated. The isotropic chemical shifts computed by (1)H and (13)C NMR analysis also show good agreement with experimental observation. Natural bond orbital (NBO) analysis has been performed on MBDH compound to analyze the stability of the molecule arising from hyperconjugative interactions and charge delocalization. Molecular electrostatic potential surface (MEP) has also been performed by DFT/cam-B3LYP method with 6-311++G(d,p) basis set. Differential scanning calorimetric measurements performed on the powder sample indicate the phase transition point approximately at 368 and 358K for heating and cooling, respectively.
authors: Department of Physics, Vel Tech University, Chennai 62, India.
authors: N
authors: N
authors: Kanagathara
authors: Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wrocław, 2, P.O. Box 937, Poland.
authors: M K
authors: MK
authors: Marchewka
authors: Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wrocław, 2, P.O. Box 937, Poland.
authors: M
authors: M
authors: Drozd
authors: St. Peter's University, Chennai 54, India.
authors: S
authors: S
authors: Gunasekaran
authors: Department of Chemistry, Government Arts College, C-Mutlur, Chidambaram 2, India.
authors: P R
authors: PR
authors: Rajakumar
authors: Department of Physics, Presidency College, Chennai 5, India. Electronic address: anbu24663@yahoo.co.in.
authors: G
authors: G
authors: Anbalagan
mesh_terms: D001565:Benzoates / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D003460:Crystallization; D004583:Electrons; D006860:Hydrogen Bonding; D007477:Ions; D008968:Molecular Conformation; D044367:Phase Transition; D011208:Powders; D066244:Proton Magnetic Resonance Spectroscopy; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D055672:Static Electricity; D014227:Triazines / Q000737:chemistry*; D014732:Vibration; D014961:X-Ray Diffraction
chemical_list: D001565:Benzoates; D007477:Ions; D011208:Powders; D014227:Triazines; C011907:melamine
keywords: FT-IR spectroscopy; FT-Raman spectroscopy; Hydrogen bonded molecular crystal