نتایج جستجو برای: nmr and el_tofms
تعداد نتایج: 16839182 فیلتر نتایج به سال:
abstractl density functional theory (dft) was used to investigate the effects of intra-moecular interactions and implicit water molecules on the relative stability and the nmr shielding tensors of hallucinogenic harmine in the monomeric and dimeric states. results represented that the relative stability and the nmr shielding tensors are dependent on the resonance interactions and chemical envir...
the potential of tobacco waste as a viable source of medicinally important flavonoids like rutin has been investigated. three flavonoids, apigenin, quercetin and rutin, have been isolated from waste tobacco leaves, and their identities have been confirmed by uv-visible, 1h-nmr and 13c-nmr spectroscopy. by using analytical hplc, the amount of rutin present in the tobacco leaves, before and after...
in this research an effective and appropriate method has been developed for one-pot synthesis of new n-phenyl fulleroisoxazoline using fe3o4@sio2 nanoparticles as a green magnetically recyclable catalyst. the prepared catalytic samples were characterized by xrd, sem, ft-ir and vsm. the products have been characterized by physical and spectroscopic data such as ir, 1h nmr, 13c nmr, and ms analyses.
in this research, so3h-functionalizedphthalimide (sfp) has been prepared through simple reaction of phthalimide with chlorosulfonic acid, and characterized using ft-ir, 1h nmr, 13c nmr, sem (scanning electron microscopy), mass and tg (thermal gravimetric) spectra. afterward, the solid acid has been utilized as an efficient, green, heterogeneous and recyclable catalyst for the solvent-free synth...
in this study, the drug atenolol on c60 fullerene were the drug and its derivatives were optimized fullerene. nbo and nmr for complex computations required in the hf/6-31g (d) and b3lyp/6-31g (d) quantum chemistry method was used. mechanical quantum calculations in theory level of b3lyp/6-31g were performed on structure of atenolol and nano fullerene atenolol with different positions of linking...
the imine intermediate generated by the addition of primary amine to the cinnamaldehyde is trapped by the n-isocyaniminotriphenylphosphorane (ph3pnnc) and a carboxylic acid, and leads to the formation of the corresponding iminophosphorane intermediate. the 1,3,4-oxadiazole derivatives are formed via intramolecular aza-wittig reaction of the iminophosphorane intermediate. the reactions were comp...
a general synthetic route to the synthesis of imidazoles has been developed using nano sbcl5/sio2 under solvent-free conditions. the multi-component reactions of aldehydes, benzil and ammonium acetate were carried out to afford some trisubstituted imidazole derivatives. this method provides several advantages like simple work-up, environmentally benign, and shorter reaction times along with hig...
a green and convenient protocol is described for the preparation of 1-(alkylamino)-3-(1,3-dioxoisoindolin-2-yl)-2-methyl-1-oxopropan-2-yl benzoates via one-pot three-component reaction between 2-(2-oxopropyl)isoindoline-1,3-dione, an alkyl isocyanide and an aromatic carboxylic acid in water at room temperature. the methods used to follow the reactions are tlc and nmr, which indicated that there...
chemical composition and biological activities of methanolic extract of scrophularia oxysepala boiss
isolated five known iridoids glycosides (scrophuloside a, harpagoside b, 5-hydroxyloganin, 8-o-acetylharpagide and 6-o-methyl,1-glucopyranosyl catalpol ),one phenyl ethanoid glycoside (verbascoside) and a phenyl ethanol amine (2-(4-chlorobenzyl amino) ethanol ) compound from the methanolic extract of aerial parts of scrophularia oxysepala using by high performance liquid chromatography based on...
0146-6380/$ see front matter 2008 Elsevier Ltd doi:10.1016/j.orggeochem.2008.06.006 * Corresponding author. Tel.: +1 423 439 6917; fa E-mail address: [email protected] (Y.L. Jiang). A new and convenient fluorescence spectroscopic method has been developed for the separation and determination of perylene in fossil wood recovered from a late Miocene to early Pliocene Gray Fossil Site in Tennessee, ...
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