AJP	ISSN : 0971 – 3093 Vol 23, No. 6, December, 2014

 

Vol. 23, No 6 (2014) 861-874

The infrared spectra of the gas (3500 to 80 cm^–1) and Raman spectra of the liquid (1500 to 1100 cm^–1) of cyclobutyldichlorosilane (c-C₄H₇SiHCl₂) have been recorded and complete vibrational assignments are given for all four conformers. To support the spectroscopic study, ab initio calculations by the Møller-Plesset perturbation method to second order MP2 (full) and density functional theory calculations by the B3LYP method have been carried out. The infrared intensities, Raman activities, vibrational frequencies and band contours have been predicted from MP2 (full)/6-31G(d) calculations and these theoretical values are compared to the experimental ones when available. The conformational stabilities (t-Eq > g-Eq > t-Ax > g-Ax) have been predicted from theoretical calculations with basis sets up to 6-311+G(2d,2p) from both MP2(full) and density functional theory calculations by the B3LYP method. The results are discussed and compared to the corresponding properties of some related molecules.© Anita Publications. All rights reserved.

Keywords: cyclobutyldichlorosilane; vibration; conformations.

 Vol. 23, No 6 (2014) 875-882

The monolayers of 2-mercaptopurine (2MP) were self-assembled at the roughened polycrystalline gold surface in acid and alkaline media. The interpretation of SERS mapping spectral data aided by the calculations for the vibrational modes using BLYP/6-31G method suggested that the resulted 2MP monolayers under acid condition through the S and N₃ atoms of pyrimidine moiety anchoring at the gold surface in a tilted fashion and in basic solution, formation of 2MP molecules by the interaction of the C=S bond and N₁ atom with the surface. In-situ SERS spectroelectrochemical experiment was conducted to examine the stability of the SAMs, and it was found the detaching process of the 2MP SAMs formed under acid media had happened around -1.6 V vs SCE. The monolayers of 2MP formed at pH 13 were detached from the Au surface at ca. −1.2 V vs SCE.© Anita Publications. All rights reserved.

Keywords: 2-mercaptopurine; SERS mapping; spectral assignments.

Vol. 23, No 6 (2014) 883-890

Lattice dynamics and normal coordinate analysis of HTSCGdBa₂Cu₃O₇

 

Sujin P Jose¹, V Arjunan², K Sanghamitra³ and  S Mohan³*

Knowledge about the phonons in high temperature superconductors is essential to understand  the strong electron-phonon coupling which may be one of the possible origins of the high T_c superconductor. It is not possible to obtain all the phonon frequencies experimentally through Raman and infrared spectra due to the nature of high temperature superconducting materials. Hence, a theoretical evaluation of phonon frequencies of high temperature superconductors assumes importance. The normal coordinate analysis and lattice dynamical calculations of the optically active lattice vibrations are useful for the theoretical interpretation of Raman and infrared spectra at the center of Brillouin zone in high temperature superconductors. Therefore an attempt is made in the present work to evaluate all phonon frequencies using two different methods namely lattice dynamics studies and normal coordinate analysis. The results obtained by these two methods are discussed in detail.© Anita Publications. All rights reserved.

Keywords: GdBa₂Cu₃O₇, Phonon frequencies, Lattice dynamics, Normal coordinate analysis

 Vol. 23, No 6 (2014) 891-908

The 3,4-dihydropyrimidinones namely ethyl-4-(4-N,N-dimethylaminophenyl)-6-methyl-2-oxo-3,4-dihydropyrimidine-5-carboxylate (C1) and 5-acetyl-4-(4-N,N-dimethylaminophenyl)-6-methyl-2-oxo-3,4–dihydropyrimidine (C2) were synthesized using acetoacetic ester/acetylacetone, urea and 4-N,N-dimethylaminobenzaldehyde by grindstone technique. The purity of the compounds were determined by elemental analysis, TLC, FTIR and ¹H–NMR spectroscopic methods. The in vitro antibacterial and antifungal activities of the compounds were studied. The structural parameters for the optimised structure of the compounds were determined by B3LYP method. The molecular electrostatic potential, charges of the atoms and the HOMO–LUMO energies of the compounds were determined.© Anita Publications. All rights reserved.

Keywords: FTIR; NMR; 3,4–dihydropyrimidin–2(1H)–ones; DFT; antimicrobial.

 Vol. 23, No 6 (2014) 909-913

Optical properties of galvanostatically synthesized hydrophilic Fe doped ZnSe thin films

 

 G M Lohar^a, J V Thombare^a, S K Shinde^a, B P Relekar^a, M C Rath^b, V J Fulari^a

^a Thin Film Physics and Holography Laboratory, Department of Physics,Shivaji University, Kolhapur-416 004 (MH), India

The present investigation describes the iron (Fe) doped ZnSe thin films were successfully synthesised via galvanostatic mode of electrodeposition. These crystalline Fe doped ZnSe thin films are characterised by X-ray diffraction (XRD), Raman spectroscopy, UV-Vis spectroscopy, reflectance spectroscopy, and surface wettability. Transmittance observed to be decreases as Fe doping percent increases in the ZnSe. The reflectance, refractive index and extinction coefficient observed to be increases as percent on Fe content increases in the ZnSe thin film. Fe doped ZnSe thin films are hydrophilic in nature.© Anita Publications. All rights reserved.

Keywords: Galvanostatic, Raman spectroscopy, Reflectance, Surface wettability

 Vol. 23, No 6 (2014) 915-932

Experimental and theoretical quantum chemical investigations of 2-cis-4-trans-hexadiene and 2-trans-4-trans-hexadiene

 

V Arjunan¹, R. Durgadevi², and S Thillai Govindaraja²

¹Department of Chemistry, Kanchi Mamunivar Centre for Post-Graduate Studies, Puducherry- 605 008, India.

-cis-4-trans-hexadiene and 2-trans-4-trans-hexadiene have been carried out. In DFT, B3LYP method has been used with 6–311++G** and cc–pVTZ basis sets. The vibrational frequencies were calculated resulting in IR and Raman frequencies together with intensities and Raman depolarization ratios. The dipole moment derivatives were computed analytically. Isoelectronic molecular electrostatic potential surface and electron density surface were examined. ¹H and ¹³C NMR isotropic chemical shifts were calculated and the assignments made are compared with the experimental values. The energies of important MO’s of the compound were also determined from TD–DFT method. The stabilisation energies of the delocalization of electrons are determined. © Anita Publications. All rights reserved.

Keywords: 2-cis-4-trans-hexadiene; 2-trans-4-trans-hexadiene; DFT; FTIR; FT-Raman; NMR.

 Vol. 23, No 6 (2014) 933-944

Vibrational spectroscopic studies, electronic structure calculations and normal coordinate analysis

of 2,3,6-trichlorobenzaldehyde

 

C S Hiremath

FTIR (4000–450 cm⁻¹) spectral measurement of 2,3,6-trichlorobenzaldehyde (236CBZ) has been done. DFT (B3LY/6-311G*) calculations have been performed giving optimized structures, energies, harmonic vibrational wavenumbers, infrared intensities, and atomic displacements. Furthermore, force field calculations have been performed by normal coordinate analysis. Force field calculations showed that several normal modes are mixed in terms of the internal coordinates. A complete assignment of the observed spectra, based on spectral correlations, electronic structure and normal coordinate analysis, has been proposed. Optimization leads to CS symmetry with 7Cl-trans and 7Cl-cis forms, with 7Cl-cis-form as the low energy stable form. The energy difference between the two forms is 0.050549 kcal/mol. The results of the calculations have been used to simulate IR spectra. The SQM method, which implies multiple scaling of DFT force fields has been shown superior to the uniform scaling approach. The computed HOMO-LUMO orbitals show that charge transfer occurs within the molecule. © Anita Publications. All rights reserved.

Keywords: 2,3,6-trichlorobenzaldehyde; DFT; vibration; SQM.

 Vol. 23, No 6 (2014) 945-952

Phonon spectral studies of high temperature superconductor TmBa₂Cu₃O₇

 

V Arjunan¹, Sujin P Jose², R Jothilakshmi³ and S Mohan³

¹Department of Chemistry, Kanchi Mamunivar Centre for Post-Graduate Studies, Puducherry- 605 008, India.

³School of Physics, Madurai Kamaraj University, Madurai- 625 021

One of the possible origins to explain high T_c superconductor is the strong electron phonon coupling. Therefore, a knowledge of phonon frequencies is essential to understand the mechanism of high temperature superconductors. In order to investigate phonon spectra, Raman and infrared spectra of these systems have been studied. Unfortunately there is a little information available in the literature for complete Raman and infrared absorption spectra. The nature of the superconductivity materials does not yield all the phonon frequencies experimentally through Raman and infrared spectra. Alternatively, a theoretical evaluation of phonon frequencies of high temperature superconductors assumes importance. The calculations of lattice dynamics using the modified three body force shell model yields the required phonon frequencies. The present approach leads to a better understanding of phonon frequency of high T_c superconductor TmBa₂Cu₃O_7. The phonon frequencies of TmBa₂Cu₃O₇ are evaluated by normal coordinate analysis by using Wilson’s FG matrix method due to the strong covalent bonding nature of high temperature superconductors. The normal coordinate analysis of optically active lattice vibrations will be useful for the theoretical interpretation of vibrational spectrum at the center of Brillouin zone for TmBa₂Cu₃O₇ high T_c superconductor. Further, the evaluated potential energy distribution helps to identify the pure and mixed frequencies. Hence, the present approach is useful not only to obtain all the phonon frequencies of high temperature superconductor TmBa₂Cu₃O₇ reasonably but also to characterize it. This gives further support in understanding the phonon spectra of the high temperature superconductors. © Anita Publications. All rights resrved.

Keywords: TmBa₂Cu₃O₇, Phonon frequencies, Lattice dynamics, Normal coordinate analysis

 Vol. 23, No 6 (2014) 953-958

Scaling equation method vs single scale factor for vibrational spectra – the case of 1,4–H2–1,2,4–triazolium ion

 

M Daszkiewicz

Scaling equation method for the assignment of vibrational spectra is discussed. The root–mean–square deviation for single scale factor, linear equation and quadratic equation is calculated for 1,4–H2–1,2,4–triazolium ion. When the single scale factor is applied, large RMS is obtained. Since the difference between RMS for linear and quadratic equation is comparable with the resolution of the experimental data, a linear equation a·x + b is satisfactory for scaling the calculated wavenumbers. Thus, further using of the single scale factor is not recommended.© Anita Publications. All rights reserved.

Keywords: Scaling Factor, Theoretical Spectra, Triazole, DFT, Hybrid Materials.

 Vol. 23, No 6 (2014) 959-972

Experimental and theoretical quantum chemical investigations of trans-methylcrotonate

 

V Arjunan¹, L Devi², P Remya² and S Senthilkumari¹

A detailed conformational, vibrational, NMR and DFT studies of trans-methylcrotonate have been carried out. In DFT, B3LYP method has been used with 6-311++G** and cc-pVTZ basis sets. The vibrational wavenumbers were calculated together with intensities and Raman depolarization ratios. The dipole moment derivatives were computed analytically. Isoelectronic molecular electrostatic potential surface and electron density surface were examined. 1H and 13C NMR isotropic chemical shifts were calculated and the assignments made are compared with the experimental values. The energies of important MO’s of the compound were also determined from TD–DFT method. © Anita Publications. All rights reserved.

Keywords: trans-methylcrotonate; DFT; FTIR; FT-Raman; NMR.

 Vol. 23, No 6 (2014) 973-988

Quantum chemical investigations of carbamoylazide and its deuterated derivative

 

V Arjunan¹, R Anitha¹, S Thillai Govindaraja² and R Santhanam²

¹Department of Chemistry, Kanchi Mamunivar Centre for Post-Graduate Studies, Puducherry-605 008. India.

²Research and Development Centre, Bharathiar University, Coimbatore 641 046, India.

A detailed conformational, vibrational and DFT studies of carbamoylazide and its deuterated derivatives have been carried out. In DFT, B3LYP method has been used with 6-311++G** and cc-pVTZ basis sets. The vibrational wavenumbers were calculated resulting in IR and Raman wavenumbers together with intensities and Raman depolarization ratios. The dipole moment were computed analytically. Isoelectronic molecular electrostatic potential surface and electron density surface were examined. The energies of important MO’s of the compound were also determined from TD–DFT method. The isotopic effect on the vibrational frequencies were discussed.© Anita Publications. All rights reserved.

Keywords: carbamoylazide; DFT; FTIR; FT-Raman; NMR.

 Vol. 23, No 6 (2014) 989-998

Investigation of induction period, nucleation parameters and microhardness studies of solution grown thiosemicarbazone of benzophenone

 

G V Pandian¹ and P Anbusrinivasan²

¹Department of chemistry, T.B.M.L College, Porayar-609 307, India

Thiosemicarbazone of benzophenone (TSCBP) is grown by solution growth technique by adopting slow evaporation method from the solvent methanol. The crystal dimension up to 14 × 6.5 × 4 mm³ is obtained. The harvested crystal was purified by repeated recrystallization. The induction period was measured at various super saturations and hence the interfacial energies were evaluated. Using the interfacial tension value, the nucleation parameters such as radius of the critical nuclei (r*), the Gibbs free energy for the formation of a critical nucleus (ΔG*) and the number of molecules in the critical nucleus (i*) were also calculated for various concentration of solvent at two different temperatures. The effect of surface tension, viscosity and density of these solvents are correlated with interfacial tension. These crystals were characterized by FTIR spectra to identify the functional group present in the compound. The optical transparency was examined by UV-spectral analysis. © Anita Publications. All rights reserved.

Keywords: Solution growth, slow evaporation technique, Induction period, Interfacial energy, spectral characterization.

 Vol. 23, No 6 (2014) 999-1012

Monomer and dimer structural stability, experimental and theoretical spectroscopic investigations (FTIR, FT-Raman and UV-Vis),

 

MEP, DOS and NLO studies of Niacin

P B Nagabalasubramanian^a and S Periandy^b

The FTIR, FT-Raman and UV-Visible spectra of niacin (C6H5NO2) were studied. The molecular geometry and vibrational frequencies of the Niacin (NA) in the ground state were calculated using B3LYP method invoking 6-311++G(d,p) basis set. The fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. The stability of the molecule was confirmed by calculating the energies at B3LYP/6-311++G(d,p) level. Based on the position of the carboxyl group in NA, four conformers are possible among which C1 form is more stable than others. The vibrational wavenumbers of Cs conformer with monomer and dimer structures were studied. The electronic properties, such as excitation energies, oscillator strength, wavelengths, HOMO and LUMO energies, were performed by time-dependent density functional theory. In addition, the dipole moment, linear polarizability and first hyperpolarizability values were computed. The linear polarizabilities and first hyper polarizabilities of the studied molecule indicate that the compound is a good candidate for nonlinear optical materials. © Anita Publications. All rights reserved.

Keywords: Niacin, FTIR, FT-Raman, UV-Visible, HOMO–LUMO, NLO.

Vol. 23, No 6 (2014) 1013-1023

The titanium-doped indium oxide (InTiO) thin films were deposited onto glass substrate by spray pyrolysis technique. The structural, optical and electrical properties with titanium doping were investigated. XRD pattern of the prepared films confirmed the formation of pure single cubic phase with a preferred orientation along (222) plane with the average crystallite size ranging in between 25 and 35 nm. The other crystallographic parameters microstrain, dislocation density, and lattice constants were estimated. The average optical transmittance of the films varied from 65% to 92% in the visible region depending on doping content. The optical band gap of the films was found to decrease with increasing Ti concentration, from 3.63 for pure In₂O₃ up to 3.1 eV for 13% Ti. Topography of the films was studied by AFM analysis. FTIR and FT-Raman studies confirm the polycrystalline nature of the cubic structure of In₂O₃. Room temperature photoluminescence  spectra reveal mainly two major peaks, blue emission at 415 nm and a broad peak at 674 nm. The observed resistivity of the films decreases with increase of mobility for the doped films.© Anita Publications. All rights reserved.

Keywords: Indium titanium oxide, Spray pyrolysis, FT-Raman, AFM, Electrical resistivity.

 Vol. 23, No 6 (2014) 1025-1030

Pollutant free and eco-friendly synthetic route using herbal plant A. indica, which can be used as an effective capping as well as reducing agent, is used for the synthesis of silver nanoparticles (Ag NP’s) and their antimicrobial activity is studied. Silver nanoparticles formation is confirmed from surface plasmon absorption identified from optical absorption studies. Functional groups present in the crude neem extract and synthesized nanoparticles (NP’s) with neem extract are analyzed by using FTIR studies. The antimicrobial screening of six different bacteria and four fungi strains were challenged against biosynthesized Ag NP’s by using A. Indica. © Anita Publications. All rights reserved.

Keywords: Silver nanoparticles, Antimicrobial; Bio-synthesised.

Total Refs : 21

The FTIR, FT-Raman, ¹³C NMR and ¹H NMR spectra of the sulphanilamide were recorded. The observed fundamental wavenumbers (IR and Raman) were assigned. The hybrid computational calculations have been carried out by HF and DFT (B3LYP) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets. The modifications of the structure of the compound due to the substitutions of NH₂ and SO₂ were investigated. Moreover, NMR spectra were simulated by using the gauge independent atomic orbital (GIAO) method, with B3LYP methods and the 6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts related to TMS were compared. A study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, were performed by HF and DFT methods. The kubo gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand group. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the title compound at different temperatures were calculated in gas phase. © Anita Publications. All rights reserved.

Keywords: Sulphanilamide; Kubo gap; HOMO LUMO; Gauge independent atomic orbital; Electrostatic potential.

 Vol. 23, No 6 (2014) 1041-1052

 Biologically driven approaches for the synthesis of nanomaterials

 

Abu A Ansary¹, Imran Uddin² and Shadab A Khan³

¹Faculty of Chemistry, Raman Imaging Group, Jagiellonian University, Krakow 30-060, Poland

²Department of Materials Science and Engineering, Korea University,

Seongbuk-gu, Anam-ro 145, Seoul, Republic of Korea

The advent of nanotechnology has led to great hopes and promises in almost every field of science. One of the prime objectives of nanotechnology is the manipulation and application of matter at the nanoscale. Eventually, acquiring control over the synthesis of materials with tailor-made properties gains importance. Having attained considerable control over the synthesis of nanomaterials utilizing methods that require ‘harsh’ conditions, researchers are eyeing on alternative methods that not only achieves better control over the properties of materials but also seek to overcome the ‘harsh’ conditions required for the syntheses. One of the best alternatives for the syntheses of nanomaterials under ambient conditions is the utilization of processes that occurs in nature e.g. microorganisms and biomolecules. This review focuses on the utilization of biological entities for the syntheses of nanoparticles. This review has been divided into two parts. The first part discusses the biologically driven syntheses of metal oxide nanoparticles and the subsequent part details the use of different biomolecules for the syntheses of different types of nanomaterials. Oxide nanoparticles are an important class of nanoparticles with applications ranging from cosmetics, to photovoltaic cells, to photocatalysts, to gas sensors. Hence, biologically driven syntheses of oxides of different elements have been chosen for this review. In addition, in order to emphasize the importance and versatility of biomolecules for the syntheses of different types of nanoparticles, biomolecules based syntheses of nanoparticles have been reviewed here.© Anita Publications. All rights reserved.

Keywords: Nanomaterials; Biomolecules; Synthesis

 Vol. 23, No 6 (2014) 1053-1062

Vibrational spectroscopic and NMR studies of 4-acetylpyridine

 

A Suvitha^a,b, S Periandy^c, S Ramalingam^d and M Govindarajan^e

^aPeriyar Maniyammai University, Vallam, Thanjavur, India

^bSt. Francis College, Bangalore, India

^cDepartment of Physics, Tagore Arts College, Puducherry-605 008, India

^dDepartment of Physics, A.V.C. College, Mayiladuthurai, Tamilnadu, India

FTIR and FT-Raman spectra of 4-acetylpyridine have been reported in the regions 4000-100 cm⁻¹ and 3500-100 cm⁻¹, respectively. Molecular geometry, infrared intensities, Raman activities and vibrational wavenumbers of 4-acetylpyridine have been calculated by using ab-initio Hartree–Fock (HF) and density functional theory DFT(LSDA/B3LYP) methods employing the 6-31+G(d,p)/6-311+G(d,p) basis sets. The experimental bands and normal modes of vibrations were assigned based on the scaled theoretical wavenumbers are good agreement with the experimental data. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. The molecular electrostatic potential (MEP) and thermodynamic properties were performed. The ¹H and ¹³C NMR chemical shift were calculated by gauge-including atomic orbital method with B3LYP/6-311++G(d,p) approach. © Anita Publications. All rights reserved.

Keywords: HF; DFT; 4-acetylpyridine; vibrational analysis; HOMO; LUMO.

 Vol. 23, No 6 (2014) 1063-1068

Kinetics studies of adsorption dsorption of rhodamine B dye onto activated carbon prepared from bark of Erythrina indica

 

V Roopa^a, K Ramesh^b, A Rajappa^c, and V Nandhakumar^d

^a,dDepartment of Chemistry, A.V.V.M Sri Pushpam College, Poondi, Thanjavur

^bDepartment of Chemistry, Arasu Engineering College, Kumbakonam

The kinetics of adsorption of Rhodamine B dye onto activated carbon prepared from bark of Erythrina Indica have been investigated. Kinetics of the system have been studied with pseudo first order, pseudo second order and intra particle diffusion models at the temperature of 305 K. SSE % revealed that present system followed first order kinetics and intraparticle diffusion as the rate determining step. Same trend was observed when the experiments were carried out at 315K and 325K also. © Anita Publications. All rights reserved.

Keywords: adsorption; kinetics; activated carbon; Rhodamine B

 Vol. 23, No 6 (2014) 1069-1078

Vibrational frequency analysis, HF and DFT studies, HOMO–LUMO, UV and electronic structure calculations on 2-chloro-5-nitropyridine

 

A Suvitha^ab, S Periandy^c, and M Govindarajan^d

^aPeriyar Maniyammai University, Vallam, Thanjavur, India

^bSt. Francies College, Bangalore, India

^cDepartment of Physics, Tagore Arts College, Puducherry-605 008, India

The FTIR and FT-Raman spectra of 2-chloro-5-nitropyridine (C₅H₃ClNO₂) molecule has been recorded. The structural parameters and spectroscopic data of the molecule in the ground state have been calculated using ab-initio Hartree–Fock and Density functional method (B3LYP/B3PW91) employing the 6-31+G(d,p), and 6-311++G(d,p) basis sets. The vibrational wavenumber were calculated and compared with experimental FTIR and FT Raman spectra. The calculated HOMO and LUMO energies show that charge transfer occurs within molecule. The influences of chlorine atom and nitro group on the geometry of pyridine and its normal modes of vibrations have also been discussed. The energy and oscillator strength calculated by Time-dependent density functional theory (TD-DFT) complements with the experimental findings. Thermodynamic properties of the title compound at different temperatures have been calculated. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) were performed. © Anita Publications. All rights reserved.

Keywords: Hartree–fock; DFT; 2-chloro-5-nitropyridine; vibrational analysis; HOMO; LUMO.

 Vol. 23, No 6 (2014) 1079-1081

Density Functional Theory

 

V. Arjunan¹ and Sujin P. Jose²

¹Department of Chemistry, Kanchi Mamunivar Centre for Post-Graduate Studies, Puducherry 605 008, India.

²Department of Computational Physics, School of Physics, Madurai Kamaraj University, Madurai 625 021, India.