نتایج جستجو برای: دینامیک nmr
تعداد نتایج: 65503 فیلتر نتایج به سال:
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...
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...
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...
aprotic diazotization of anthranilic acid with isoamylnitrite or amylnitrite gave benzenediazonium-2- carboxylate. subsequent thermal decomposition of this diazonium salt (in situ) in 1,2-dichloroethane as a solvent at 85oc and in the presence of 2,5-diethyl-3,4-diphenylcyclopentadienonaes a trapping agent gave 1,4-diethyl-2, 3-diphenylnaphthalene in high yield, after loss of carbon monoxide. a...
در این مقاله با قرار دادن مدولاتور الکترو اپتیکی در کاواک خارجی یک لیزر نیمرسانا و مدوله کردن پسخوراند اپتیکی، تغییرات دینامیک شدت خروجی لیزر مورد مطالعه قرار گرفته است. این امر به وسیله نمودارهای دوشاخه شدگی و تحول زمانی نسبت به پارامترهای ضریب دامنه مدولاسیون اعمال شده و فرکانس ولتاژ مدولاسیون مربوط به مدولاتور الکترو اپتیکی به صورت عددی مورد آنالیز قرار گرفته است. در این مطالعه نشان دادیم ک...
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