نتایج جستجو برای: nmr chemical shielding parameters

تعداد نتایج: 986552  

M. Monajjemi M. Sheikhi

In this research, the Magnetite nanoparticles (Fe304) were prepared by coprecipitation of Fe- andGinger is a well known spice and flavoring agent which has also been used in traditional medicine inmany countries. Ginger contains essential oils including gingerol and zingiberene. It also containspungent principles such as zingerone, and shogaol. In the paper six theoretical methods were used toc...

A.H. Esmailian B. Khalili Hadad F. Mollaamin K. Shahanipour

As drug delivery systems Nanoparticulan widely investigated because of many advantages such as smaller size,controlled drug release potentiaL targeting ability, enhancement of therapeutic efficacy and reduction oftoxicity. So, carbon nanotubes have recently received considerable attention as alternative drug delivery carrierIn this study we investigate interaction of tamoxifen with open-end of ...

F. Mollaamin S. M. Sadat Choobeh

A cluster model for active site of nanotube (C48) was presented and investigated the geometricstructure and thermochemical parameters. Quantum-mechanical calculations were performed at theHF / 510-30, 6-310, 6-3 IG• and 6-310" levels of theory in the gas phase and three solvents atfour temperatures. Also, nuclear shielding parameters of the active site of nanotube have been takeninto account us...

Journal: :journal of physical & theoretical chemistry 2005
m. monajjemi t. karimkeshteh f. mollaamin

in this paper, the hydrogen bonding (hb) effects on the nmr chemical shifts of selected atoms in serineand serine-nh2o complexes (from one to ten water molecules) have been investigated with quantummechanical calculations of the 15n and 13c tensors. interaction with water molecules causes importantchanges in geometry and electronic structure of serine.for the compound studied, the most importan...

Journal: :Physical chemistry chemical physics : PCCP 2010
Anu M Kantola Perttu Lantto Juha Vaara Jukka Jokisaari

The series of methyl halides, CH(3)X (X = F, Cl, Br, and I), is prototypic for demonstrating the s.c. normal halogen dependence of light-atom nuclear magnetic resonance shielding constants in the presence of halogen atoms of varying electronegativity. We report a systematic experimental and first-principles theoretical study of the (13)C and (1)H shielding tensors in this series. The experiment...

In this research, geometrical structures of armchair single walled boron nitride nanotube (SWBNNT) and armchair single walled aluminum nitride nanotube (SWAlNNT) were optimized by Density Functional Theory (DFT) in the gas phase, both having the same length of 5 angstrom and n=9, m=9. B3LYP/6-31G* level of theory have been used to determine and compare electronic properties, n...

In this research, geometrical structures of armchair single walled boron nitride nanotube (SWBNNT) and armchair single walled aluminum nitride nanotube (SWAlNNT) were optimized by Density Functional Theory (DFT) in the gas phase, both having the same length of 5 angstrom and n=9, m=9. B3LYP/6-31G* level of theory have been used to determine and compare electronic properties, n...

Hooriye Yahyaei Neda Hasanzadeh

In this research, Quantum-mechanical calculations were performed at the HF method with the 6-31+G*basis set and at the B3LYP method with the 6-31+G* basis set in the gas phase and five solvents such as water, DMSO, methanol, ethanol and dichloromethane at six temperatures. According to these theoretical results of IR, we extracted thermo chemical parameters such as enthalpy (∆H Kcal/mol), Gibbs...

Journal: :Chemistry 2006
Avital Steinberg Miriam Karni David Avnir

Molecular symmetry is a key parameter which dictates the NMR chemical shielding anisotropy (CSA). Whereas correlations between specific geometrical features of molecules and the CSA are known, the quantitative correlation with symmetry--a global structural feature--has been unknown. Here we demonstrate a CSA/symmetry quantitative relation for the first time: We study how continuous deviation fr...

2011
Matti Hanni

This thesis presents computational studies of both the static and dynamic parameters of the nuclear magnetic resonance (NMR) spectroscopy of gaseous xenon. First, state-of-the-art static magnetic resonance parameters are computed in small xenon clusters by using methods of quantum chemistry, and second, time-dependent relaxation phenomena are investigated via molecular dynamics simulations at d...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید