55 research outputs found
X-ray structure analysis and vibrational spectra of Furosemide
In this study, FT-IR, FAR-IR, and FT-Raman spectra of Furosemide were recorded between 4000 and 650 cm(-1), 700 and 150 cm(-1) and 4000 and 150 cm(-1) regions, respectively. In addition, the single crystal, X-ray structure is determined for this molecule. The X-ray analysis showed two alternative orientations; E and Z-form which formed dimer structure by O-H center dot center dot center dot O hydrogen bonds. The theoretical analysis of probable stable conformers of Furosemide was carried out by using DFT method with 6-31G(d,p) basis set while density functional theory (DFT/B3LYP) method with 6-31G(d,p), 6-31G(d) and Sadlej PVTZ as basis sets was used for quantum chemical calculations of geometrical structure and vibrational wavenumbers. Additionally, the anharmonic wavenumbers were calculated by using the same theory with 6-31G(d,p) basis set. A detailed interpretation of the infrared and Raman spectra of Furosemide was made based on total energy distribution (TED). Finally, probable donor-acceptor interactions of E and Z form of the molecule were examined by using NBO analysis. (C) 2012 Elsevier B.V. All rights reserved
Theoretical and experimental vibrational spectra of kyotorphin dipeptide
The vibrational wavenumbers of kyotorphin [L-Tyr(1)-D-Arg(2)] analogue (D-KTP) was determined by using theoretical and experimental methods. The optimised structure of kyotorphin was obtained on the basis of parameter set determined for L-tyrosine and D-arginine molecules. After then the vibrational wavenumbers of kyotorphin were calculated by density functional theory (DFT) approximation, using the B3LYP function with 6-3 1 G(d,p) basis set. The vibrational assignment was given by the help of total energy distribution (TED) of the vibrational modes of the D-KTP. The characteristic Fermi doubled of tyrosine was observed at 853 and 828 cm(-1) in the Raman spectrum of D-KTP and the intensity ratio (I-853/I-828) was found to be 1.6, indicating that both phenoxyl proton and oxygen are involved in H-bonding interaction in D-KTP. (c) 2004 Elsevier B.V. All rights reserved
Global Optimization and Vibrational Frequencies of Lennard-Jones Cluster Containing 7 Atoms
Vibrational analysis of isonicotinamide
The FT-IR and FIF-Raman spectra of isonicotinamide (in solid phase) have been recorded in the regions 4000-400 and 4000-70 cm(-1), respectively. The geometry optimizations and vibrational spectrum calculations of isonicotinamide have been carried out at the DFT/B3LYP level with 6-31 + + G(d,p) basis set. With the SQM approach, the force field of isonicotinamide obtained by DFT calculations has been corrected by a set of scaling factors to get a good agreement between observed and calculated wavenumbers. Isonicotinamide interacting with AI(OH)(3) has also been studied by B3LYP/6-31 + + G(d,p) calculations and the SQM results of both molecules have been compared to investigate how the coordination through the ring nitrogen effects the isonicotinamide vibrational wavenumbers. (c) 2004 Elsevier B.V. All rights reserved
Regular and chaotic solutions in BEC for tilted bichromatical optical lattice
We investigate a Bose-Einstein condensate held in a 1D tilted bichromatical optical lattice potential by constructing its Poincare sections in phase space. We explore dynamic of the system based on the relations between the system parameters and the solution behaviors. It is demonstrated that the system exhibits shock-wave like dynamic. The power spectrum graphs, bifurcation and Lyapunov exponents of BEC system are also presented
Beyond convergence: Poland and Turkey en route to high income
This paper compares and contrasts the policy reform experiences of Poland and Turkey en route to high income. For both countries, globalization has presented unprecedented opportunities to catch up, unleased by integration into European and global markets and the establishment of macroeconomic discipline. These opportunities were reinforced by the creation of economic institutions to strengthen competition and support private entrepreneurship, catalyzed by the convergence process with the European Union. Both Poland and Turkey have shown resilience following the 2008 global crisis, but continued success will require renewed structural reform measures. Dealing with the challenging of aging while at the same time finding a way to sustain productivity growth through greater domestic innovation is shaping Poland’s policy agenda. Turkey's structural and demographic potential as well as its strategic location between the markets of Europe and Asia offers attractive value proposition to investors, which could be further enhanced with improvements in business regulations and economic governance
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