نتایج جستجو برای: h nmr
تعداد نتایج: 578829 فیلتر نتایج به سال:
H and C NMR spectra remain the first tool used by chemists to perform the structure elucidation of their products on a routine basis. It is common to provide NMR data on both proton and carbon spectra based on one-dimensional experiments. The increasing complexicity of natural compounds and their synthetic related derivatives implies the use of some more recent 1D and 2D NMR techniques. The pur...
Water in Silicate Glasses: Quantitation and Structural Studies by 'H Solid Echo and MAS-NMR Methodst
'H wideline and magic angle spinning (MAS) NMR results are reported for water in a series of synthetic and naturally occurring silicate glasses containing from 0.04 to 9.4 wt % H20. For glasses free of paramagnetic metal ions, the absolute water contents can be accurately determined by a solid echo IH NMR technique with pyrophyllite, A12Si,010(OH)2, as an intensity reference. The MAS-NMR spectr...
Succinimidinium hydrogensulfate ([H-Suc]HSO4), as a new and stable derivative of succinimide, is easily prepared by the reaction of succinimide with neat sulfuric acid. This ionic liquid can be used as an efficient catalyst for the acetylation of alcohols, phenols, thiols and amines at room temperature under mild and solvent free conditions. All the products are separated and identified using d...
A new homologous series of linear aliphatic polyesters, such as poly (cis-2- butenylene carboxylate)S, PBms (m is the number of methylene groups in the acid component, m=2-8 have been synthesized by direct polyesterification reactions in anisole, as solvent. FT-IR, 400 MHz H- NMR, C-NMR and elemental analysis were used to establish the structure of polyesters. Molecular weight distributi...
Recent advancements in magnetic resonance imaging (MRI) have enabled clinical imaging of human cortical bone, providing a potentially powerful new means for assessing bone health with molecular-scale sensitivities unavailable to conventional X-ray-based diagnostics. To this end, (1)H nuclear magnetic resonance (NMR) and high-resolution X-ray signals from human cortical bone samples were correla...
The paper describes a convenient method for the preparation of 4-substituted phenyl-5-[1-(4-fluorophenyl)-1,3-dihydroisobenzofuran-5-yl]-2H-1,2,4-triazole-3-thiones. The structures of the synthesized compounds are established by the results of LCMS, (1)H NMR, (13)C NMR, and IR and elemental analyses. The mercaptotriazoles are indicated to be in thione form by (1)H NMR spectra. All the synthesiz...
4-n- prophyl- 1,2,4- triazoline-3-5- dione was synthesized from n-propylisocyanate and ethylhydrazine carboxylate in several steps. the title compound was isolated as pink crystals in high yield and purity. this compound was fully characterized by ir and h-nmr spectroscopy
the synthesis and properties of new monoazo dyes derived from the diazonium salts of paminobenzoic acid, 3-trifluoromethyl aniline , 4-trifluoromethyl aniline are considered .theprepared compounds were characterized by uv-visible , ft-ir and h nmr spectroscopictechniques . the effect of varying solvent upon the absorption ability of p-amino benzoic acidcoupled with 4,4 —diethyl aniline , anilin...
While obtaining high-resolution structural details from bone is highly important to better understand its mechanical strength and the effects of aging and disease on bone ultrastructure, it has been a major challenge to do so with existing biophysical techniques. Though solid-state NMR spectroscopy has the potential to reveal the structural details of bone, it suffers from poor spectral resolut...
Background and Aims: Since 1980's, several preclinical studies have been published on the anti-colorectal cancer activity of nonsteroidal anti-inflammatory drug indomethacin. The direct anti-proliferative effect indomethacin seems to occur via a variety reported COX-independent mechanisms. Acemetacin is glycolic acid ester derivative contrary indomethacin, there not much research anti-cancer ef...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید