Nowadays NMR spectroscopy becomes a powerful tool in chemistry because of the NMR chemical shifts. Hartree–Fock theory and the Gauge-including atomic orbital (GIAO) methods are used in the calculation of 29Si NMR chemical shifts of various silicate species in the silicate solution as initial components for zeolite synthesis both in gas and solution phase. Calculations have been performed at geo...

background celiac disease (cd) is a disorder associated with body reaction to gluten. after the gluten intake, an immune reaction against the protein occurs and damages villi of small intestine in celiac patients gradually. objectives the osc, a filtering method for minimization of inter- and intra-spectrometer variations that influence on data acquisition, was applied to biofluid nmr data of c...

abstarct:a simple one-pot synthesis of pyrano[ 2,3-c]pyrazoles was developed by a three-component reaction of various benzaldehydes, malononitrile and 1-phenyl or hydro-3-methyl-1h-pyrazol-5(4h)-one in the presence of n-methyl pyridinium p-toluene sulfonate (nmpyts) as a catalyst. all of the synthesized compounds were identified by ir, 1h nmr, 13c nmr and mass spectroscopy techniques. in the me...

achillea tenuifolia lam (asteraceae) afforded a methanolic extract from which after fractionation in solvents with different polarities two known flavones 3’, 5- dihydroxy- 4’, 6, 7- trimethoxy flavone (eupatorine, compound 3), 5- hydroxy- 3’, 4’, 6, 7- tetramethoxyflavone (compound 4), besides stearic acid (compound 1 ), lupeol (compound 2), daucosterol (β- sitosterol 3-o- β- d- glucopyranosid...

Permeability is arguably the most important property in evaluating fluid flow in the reservoir. It is also one of the most difficult parameters to measure in field. One of the main techniques for determining permeability is the application of Nuclear Magnetic Resonance (NMR) logging across the borehole. However, available correlations in literature for estimating permeability from NMR data do n...

BCN compounds have been researched theoretically and experimentally widely. In this paper, weintroduce the theoretical prediction of ternary B-C-N compounds. NMR spectroscopy was employedextensively to study these ternary nanostructures. We discuss the utilization of chemical shiftinformation as well as ab initio calculations of nuclear shielding for H20134C9N4 structuredetermination. We calcul...

Lycium species is a popular medicinal plant in the traditional Chinese medicine and Lycium ruthenicum is a native medicinal plant of Iran. Lycium genus has several biologically important properties too. Investigation of chemical composition of ethyl acetate extract of this plant is the goal of this study. Two coumarins (Scopoletin and Sculetin) and Methyl-2-hydroxy-4-undecanoxy-trans-cinamate w...

An efficient synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles by one-step condensation of  an aldehyde, benzil, ammonium acetate and primary amine in the presence of nanocrystalline magnesium aluminate under microwave irradiation is described. The advantages of this catalyst are including simple work-up, low cost and reusability. Compared with conventional methods, the ...

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 one pot green three‐component coupling reaction of aldehyde, phenylacetylene, and amine derivatives in the presence of copper (II)–thioamide combination as a novel and efficient heterogeneous catalyst under solvent–free conditions is reported. The catalyst displayed high activity and afforded the corresponding propargylamines in good to high yields. The key to this procedure was the generatio...