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N Sundaraganesan - One of the best experts on this subject based on the ideXlab platform.
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ft ir ft raman nmr and uv vis spectra vibrational assignments and dft calculations of 4 butyl benzoic acid
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2012Co-Authors: M Karabacak, Zeliha Cinar, Mustafa Kurt, S Sudha, N SundaraganesanAbstract:Abstract The solid phase FTIR and FT-Raman spectra of 4-butyl benzoic acid (4-BBA) have been recorded in the regions 400–4000 and 50–4000 cm −1 , respectively. The spectra were interpreted in terms of fundamentals modes, combination and overtone bands. The structure of the molecule was optimized and the structural characteristics were determined by density functional theory (DFT) using B3LYP method with 6-311++G(d,p) as basis set. The vibrational frequencies were calculated for monomer and dimer by DFT method and were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. The infrared and Raman spectra were also predicted from the calculated intensities. 13 C and 1 H NMR spectra were recorded and 13 C and 1 H nuclear magnetic resonance chemical shifts of the molecule were calculated using the gauge independent atomic orbital (GIAO) method. UV–visible spectrum of the compound was recorded in the region 200–400 nm and the electronic properties HOMO and LUMO energies were measured by time-dependent TD-DFT approach. The geometric parameters, energies, harmonic vibrational frequencies, IR intensities, Raman intensities, chemical shifts and absorption wavelengths were compared with the available experimental data of the molecule.
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synthesis x ray crystallography characterization vibrational spectroscopic molecular electrostatic potential maps thermodynamic properties studies of n n di p thiazole formamidine
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2011Co-Authors: Mohammad Kazem Rofouei, Ehsan Fereyduni, N Sohrabi, Mojtaba Shamsipur, Attar J Gharamaleki, N SundaraganesanAbstract:Abstract In this work, we will report a combined experimental and theoretical study on molecular and vibrational structure of N,N′-di(p-thiazole)formamidine (DpTF). DpTF has been synthesized and characterized by elemental analysis, FT-IR, FT-Raman, 1H NMR, 13C NMR spectroscopy and X-ray single crystal diffraction. The FT-IR and FT-Raman spectra of DpTF were recorded in the solid phase. The optimized geometry was calculated by HF and B3LYP methods using 6-31G(d) basis set. The FT-IR and FT-Raman spectra of DpTF was calculated at the HF/B3LYP/6-31G(d) level and were interpreted in terms of potential energy distribution (PED) analysis. The scaled theoretical wavenumber showed very good agreement with the experimental values. A detailed interpretation of the infrared and Raman spectra of DpTF was reported. On the basis of vibrational analyses, the thermodynamic properties of the title compound at different temperatures have been calculated, revealing the correlations between Cp,m °, Sm °, Hm ° and temperatures. Furthermore, molecular electrostatic potential maps (MESP) and total dipole moment properties of the compound have been calculated.
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ft ir ft raman spectra and ab initio hf and dft calculations of 4 n n dimethylamino pyridine
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2008Co-Authors: N Sundaraganesan, S Kalaichelvan, C Meganathan, Dominic B Joshua, J P CornardAbstract:Abstract In this work, we will report a combined experimental and theoretical study on molecular and vibrational structure of 4-N,N′-dimethylamino pyridine (4NN′DMAP). The Fourier transform infrared and Fourier transform Raman spectra of 4NN′DMAP was recorded in the solid phase. The optimized geometry was calculated by HF and B3LYP methods with 6-31G(d,p) and 6-311++G(d,p) basis sets. The harmonic vibrational frequencies, infrared intensities and Raman scattering activities of the title compound were performed at same level of theories. The scaled theoretical wavenumber showed very good agreement with the experimental values. The thermodynamic functions of the title compound was also performed at HF/6-31G(d,p) and B3LYP/6-311++G(d,p) level of theories. A detailed interpretation of the infrared and Raman spectra of 4NN′DMAP was reported. The theoretical spectrograms for FT-IR and FT-Raman spectra of the title molecule have been constructed.
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molecular structure and vibrational spectra of 3 chloro 4 fluoro benzonitrile by ab initio hf and density functional method
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2008Co-Authors: N Sundaraganesan, C Meganathan, Dominic B Joshua, P Mani, A JayaprakashAbstract:Abstract In this work, the experimental and theoretical spectra of 3-chloro-4-fluoro benzonitrile (3C4FBN) were studied. The Fourier transform infrared and Fourier transform Raman spectra of 3C4FBN were recorded in the solid phase. The optimized geometry was calculated by HF and B3LYP methods with 6-311++G(d,p) basis set. The harmonic-vibrational frequencies, infrared intensities and Raman scattering activities of the title compound were performed at and HF/B3LYP/6-311++G(d,p) level of theories. The scaled theoretical wave number showed very good agreement with the experimental values. The thermodynamic functions of the title compound was also performed at HF/6-31G(d,p) and B3LYP/6-311++G(d,p) level of theories. A detailed interpretation of the infrared and Raman spectra of 3C4FBN was reported. The theoretical spectrograms for FT-IR and FT-Raman spectra of the title molecule have been constructed.
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ftir ft raman spectra and ab initio dft vibrational analysis of 2 amino 5 chloropyridine
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2006Co-Authors: N Sundaraganesan, S Ilakiamani, B Anand, H Saleem, Dominic B JoshuaAbstract:Abstract The FTIR and FT-Raman spectra of 2-amino-5-chloropyridine (ACP) has been recorded in the region 4000–400 and 3500–100 cm −1 , respectively. The optimized geometry, frequency and intensity of the vibrational bands of ACP were obtained by the ab initio and density functional theory (DFT) levels of theory with complete relaxation in the potential energy surface using 6-31G(d,p) and 6-311 + G(2df,2p) basis sets. The harmonic vibrational frequencies were calculated and the scaled values have been compared with experimental FTIR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. The experimental spectra also coincide satisfactorily with those of theoretically constructed bar type spectrograms.
V G Savitski - One of the best experts on this subject based on the ideXlab platform.
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pulsed kgd wo4 2 raman laser towards emission linewidth narrowing
Devices and Methods of Measurements, 2015Co-Authors: V G SavitskiAbstract:The linewidth of a KGd(WO4)2 pulsed Raman laser is analysed experimentally for different configurations of the Raman and pump resonators: with narrow and broadband pump emission profiles, with and without linewidth narrowing elements in the Raman laser resonator, with and without injection seeding into the Raman cavity. The benefits of a narrow linewidth pump source in combination with linewidth narrowing elements in the Raman laser cavity for the efficient linewidth narrowing of the Raman emission are explained. 20 kW peak-power pulses at 1156 nm with 0,43 cm -1 emission linewidth are demonstrated from an injection seeded KGW Raman laser.
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experimental analysis of emission linewidth narrowing in a pulsed kgd wo4 2 raman laser
Optics Express, 2014Co-Authors: V G SavitskiAbstract:The linewidth of a KGd(WO4)2 (KGW) intracavity pumped Raman laser is analyzed experimentally for different configurations of the Raman and pump laser resonators: with narrow and broadband pump emission profiles, with and without linewidth narrowing elements in the Raman laser resonator, with and without injection seeding into the Raman cavity. The benefits of a narrow linewidth pump source in combination with linewidth narrowing elements in the Raman laser cavity for the efficient linewidth narrowing of the Raman laser emission are explained. 20 kW peak-power pulses at 1156 nm with 0.43 cm−1 emission linewidth are demonstrated from an injection seeded KGW Raman laser.
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characterization of single crystal synthetic diamond for multi watt continuous wave raman lasers
IEEE Journal of Quantum Electronics, 2012Co-Authors: V G Savitski, M D Dawso, D. Urns, Ia Friel, Jennifer E. Hastie, A J KempAbstract:A continuous-wave diamond Raman laser is demonstrated with an output power of 5.1 W at 1217 nm. This Raman laser is intracavity pumped by a side-pumped Nd:YLF rod laser: a 43-fold brightness enhancement between the Nd:YLF and diamond Raman lasers is observed, with the M2 beam propagation factor of the diamond Raman laser measured to be <; 1.2. Although higher output powers are demonstrated in a similar configuration using KGd(WO4)2 (KGW) as the Raman laser material (6.1 W), the brightness enhancement is much lower (2.5 fold) due to the poorer beam quality of the KGW Raman laser (M2 <; 6). The Raman gain coefficient of single-crystal synthetic diamond at a pump wavelength of 1064-nm is also measured: a maximum value of 21±2 cm/GW is returned compared to 5.7±0.5 cm/GW for KGW at the same wavelength.
Dominic B Joshua - One of the best experts on this subject based on the ideXlab platform.
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ft ir ft raman spectra and ab initio hf and dft calculations of 4 n n dimethylamino pyridine
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2008Co-Authors: N Sundaraganesan, S Kalaichelvan, C Meganathan, Dominic B Joshua, J P CornardAbstract:Abstract In this work, we will report a combined experimental and theoretical study on molecular and vibrational structure of 4-N,N′-dimethylamino pyridine (4NN′DMAP). The Fourier transform infrared and Fourier transform Raman spectra of 4NN′DMAP was recorded in the solid phase. The optimized geometry was calculated by HF and B3LYP methods with 6-31G(d,p) and 6-311++G(d,p) basis sets. The harmonic vibrational frequencies, infrared intensities and Raman scattering activities of the title compound were performed at same level of theories. The scaled theoretical wavenumber showed very good agreement with the experimental values. The thermodynamic functions of the title compound was also performed at HF/6-31G(d,p) and B3LYP/6-311++G(d,p) level of theories. A detailed interpretation of the infrared and Raman spectra of 4NN′DMAP was reported. The theoretical spectrograms for FT-IR and FT-Raman spectra of the title molecule have been constructed.
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molecular structure and vibrational spectra of 3 chloro 4 fluoro benzonitrile by ab initio hf and density functional method
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2008Co-Authors: N Sundaraganesan, C Meganathan, Dominic B Joshua, P Mani, A JayaprakashAbstract:Abstract In this work, the experimental and theoretical spectra of 3-chloro-4-fluoro benzonitrile (3C4FBN) were studied. The Fourier transform infrared and Fourier transform Raman spectra of 3C4FBN were recorded in the solid phase. The optimized geometry was calculated by HF and B3LYP methods with 6-311++G(d,p) basis set. The harmonic-vibrational frequencies, infrared intensities and Raman scattering activities of the title compound were performed at and HF/B3LYP/6-311++G(d,p) level of theories. The scaled theoretical wave number showed very good agreement with the experimental values. The thermodynamic functions of the title compound was also performed at HF/6-31G(d,p) and B3LYP/6-311++G(d,p) level of theories. A detailed interpretation of the infrared and Raman spectra of 3C4FBN was reported. The theoretical spectrograms for FT-IR and FT-Raman spectra of the title molecule have been constructed.
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ftir ft raman spectra and ab initio dft vibrational analysis of 2 amino 5 chloropyridine
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2006Co-Authors: N Sundaraganesan, S Ilakiamani, B Anand, H Saleem, Dominic B JoshuaAbstract:Abstract The FTIR and FT-Raman spectra of 2-amino-5-chloropyridine (ACP) has been recorded in the region 4000–400 and 3500–100 cm −1 , respectively. The optimized geometry, frequency and intensity of the vibrational bands of ACP were obtained by the ab initio and density functional theory (DFT) levels of theory with complete relaxation in the potential energy surface using 6-31G(d,p) and 6-311 + G(2df,2p) basis sets. The harmonic vibrational frequencies were calculated and the scaled values have been compared with experimental FTIR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. The experimental spectra also coincide satisfactorily with those of theoretically constructed bar type spectrograms.
Amalia Dopazo Otero - One of the best experts on this subject based on the ideXlab platform.
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analysis of adipate ester contents in poly vinyl chloride plastics by means of ft raman spectroscopy
Vibrational Spectroscopy, 2006Co-Authors: Rolf W Berg, Amalia Dopazo OteroAbstract:Abstract Fourier transform (FT-) Raman spectroscopy excited with a 1064 nm laser can be used to determine the content of plasticizers in commercial flexible poly vinyl chloride (PVC) products. Our previous study [T. Norbygaard, R.W. Berg, Analysis of phthalate ester content in PVC plastics by means of FT-Raman Spectroscopy, Appl. Spectrosc. 58 (4) (2004) 410–413]—on detection of the presence of phthalate esters in PVC by FT-Raman spectroscopy—is here extended to the similar case of adipate esters (AEs) in samples of soft poly vinyl chloride plastics. Spectra of a range of adipate ester plasticizers (11 AEs) in pure form are reported. We studied if qualitative and quantitative determination of the adipate ester content would be possible based on the use of proper reference samples. It was found that AEs as a group cannot be definitively identified by their characteristic Raman bands because other aliphatic dicarboxylic esters have very similar bands. This limits the detection as to what kind of ester and how much is present in a sample. An essential finding was however that one can use the absence of any Raman band in the 1020–1060 cm−1 range of the adipate esters, as a means to verify that a given soft PVC plastics sample does not contain significant amounts of phthalate esters because these plasticizers do have strong bands at around 1060 cm−1. Furthermore it must be remembered that bands may occur at around 1040 cm−1 in a PVC sample for other reasons than phthalate ester content.
W Kiefer - One of the best experts on this subject based on the ideXlab platform.
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continuous wave raman generation in a diode pumped nd 3 kgd wo 4 2 laser
Optics Letters, 2005Co-Authors: A A Demidovich, A S Grabtchikov, V A Lisinetskii, V N Burakevich, V A Orlovich, W KieferAbstract:Continuous-wave Raman generation in a compact solid-state laser system pumped by a multimode diode laser is demonstrated. The Stokes radiation of stimulated Raman scattering at 1.181 microm is generated as a result of self-frequency conversion of the 1.067 microm laser radiation in Nd3+:KGd(WO4)2 crystal placed in the cavity. The Raman threshold was measured at 1.15 W of laser diode power. The highest output power obtained at the Stokes wavelength was 54 mW. The anomalous delay of Raman generation relative to the start of laser generation (the oscillation buildup) due to slow accumulation of Stokes photons in the cavity at low Raman gain and Raman threshold dependence not only on the laser intensity but also on the time of laser action are observed.
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vibrational spectroscopic study of tetracalcium phosphate in pure polycrystalline form and as a constituent of a self setting bone cement
Journal of Biomedical Materials Research, 1998Co-Authors: U Posset, E Locklin, R Thull, W KieferAbstract:Polycrystalline tetracalcium phosphate (TTCP), a material of considerable interest for human implantation due to its similarity to hydroxyapatite, was studied by means of Raman and FT-IR spectroscopy. The spectra were interpreted on the basis of group theoretical considerations. In addition, the setting reaction of a calcium phosphate cement (CPC) consisting of an equimolar mixture of TTCP and dicalcium phosphate (DCPA) was investigated by Raman spectroscopy. The band of the totally symmetric phosphate mode ν1 of TTCP showed marked factor group splittings. The splitting components arose at coincident wave numbers in the IR and Raman spectra. This observation was in accordance with space group P21 (factor group C22, Z = 4). The characteristic splitting of ν1 allowed the setting reaction of CPC to hydroxyapatite to be followed. According to the Raman spectroscopic results, considerable amounts of TTCP must be present at the sample surface after 24 h of setting in an aqueous environment. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 40, 640–645, 1998.
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ft raman investigation of alkaloids in the liana ancistrocladus heyneanus
Biospectroscopy, 1998Co-Authors: E Urlaub, Jurgen Popp, W Kiefer, G Bringmann, D Koppler, H Schneider, U Zimmermann, Bernhard SchraderAbstract:The applicability of the micro-FT-Raman technique for studying alkaloids in vitro and for observing alkaloids in plant cells is demonstrated. This technique is examined using fresh plant material of Ancistrocladus heyneanus, a tropical liana known to produce pharmacologically interesting naphthylisoquinoline alkaloids as secondary metabolites. It will be shown that it is possible to localize and identify some of these alkaloids in different parts of the plant by means of Raman microspectroscopic studies. Data on the in situ structure and the spatial distribution can be obtained, which could provide information about the biosynthesis of the alkaloids in the plant.
