نتایج جستجو برای: nmr.

تعداد نتایج: 58821  

Journal: :Journal of the American Chemical Society 2001
X Sun M D Winemiller B Xiang D B Collum

Low-temperature (6)Li, (13)C, and (15)N NMR spectroscopies reveal that mixtures of n-BuLi and (1R,2S)-R'(2)NCH(R)CH(Ph)OLi (ROLi; R = Ph or Me; R'(2)N = pyrrolidino or Me(2)N) in THF/pentane afford a (n-BuLi)(3)(ROLi) (3:1) mixed tetramer and a C(2)-symmetric (n-BuLi)(2)(ROLi)(2) (2:2) mixed tetramer depending on the proportions of the reactants. The corresponding (n-BuLi)(ROLi)(3) (1:3) mixed ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده علوم پایه 1389

در قسمت اول رساله واکنش تشکیل کمپلکس یون تالیم با calix[4]crown-6 و سه مشتق دیگر آن با روشهای 203tl , 1h nmr مورد بررسی قرار گرفتند. همچنین کمپلکس یک هسته ای tlclo4 و 1,3-calix[4]bis-o-benzo-crown-6 در حالت جامد تهیه شد و ساختار بلوری x-ray آن تعیین گردید. سینتیک و مکانیسم تفکیک و تغییرات پیکربندی کمپلکس تالیم و calix[4]crown-6 با دینامیک 1h nmr مورد مطالعه قرار گرفت. یک منحنی محدب آرنیوس برای ...

2003
Zdenek Hanzálek

This article addresses the problem of the computation of instantaneous firing speed in Invariant Behavior state (IB-state) of Constant speed Continuous Petri Net (CCPN) with presence of actual conflicts. The adopted approach is based on polyhedral computations applied to specify an area of possible instantaneous firing speed. If the actual conflicts are resolved by global priorities, the instan...

2001
David Snyder Paul Driscoll Peter Domaille

Even though there were actually a number of established scientists in attendance, the meeting seemed to be geared toward graduate students and postdocs. Many of the presentations focused on giving advice about and descriptions of the process of structural determination. There was little actual discussion of either algorithms or biology, but many of the opinions were quite thought provoking and ...

Journal: :Molecules 2013
Ahmed Ashour Mohamed Amer Amani Marzouk Kuniyoshi Shimizu Ryuichiro Kondo Saleh El-Sharkawy

Phytochemical examination of corncob extracts led to the isolation of a new lignan identified as 7,7'-dihydroxy-3'-O-demethyl-4-methoxymatairesinol, together with seven known compounds, identified as β-sitosterol, β-sitosteryl-β-D-glucoside, 6β-hydroxy-campest-4-en-3-one, 5α,8α-epidioxyergosta-6,22-dien-3β-ol, tricin, kaempferol and p-coumaric acid. The isolated compounds were identified by one...

Journal: :Carbohydrate polymers 2010
Daniela Beccati Sucharita Roy Fei Yu Nur Sibel Gunay Ishan Capila Miroslaw Lech Robert J Linhardt Ganesh Venkataraman

The worldwide heparin contamination crisis in 2008 led health authorities to take fundamental steps to better control heparin manufacture, including implementing appropriate analytical and bio-analytical methods to ensure production and release of high quality heparin sodium product. Consequently, there is an increased interest in the identification and structural elucidation of unusually modif...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1998
javad sabounchei sadegh salehzadeh

195pt and 1h nmr has been used to show that addition of chlorine and bromine to [pt(cn)4]2_ in presence of perchloric acid in water results in cyanide and water scrambling with formation of eleven complexes of the type [pt(cn)4-ncl(h2o)n+1](n-1)+ (n=0, 1, 2, 3, 4). addition of nbu4oh to this solution gives (nbu4)2[pt(cn)4cl(oh)]. nmr measurements in acetone also show cyanide and hydroxyl group ...

Journal: :journal of physical & theoretical chemistry 2014
maryam mehdizadeh barforushi karim zare

the dopamine has been studied theoretically at the b3lyp/6-31g* level were performed in gasphase. we calculated physical parameters like atomic charges, energy (=>), asymmetry parameter(?), chemical shift @iso, dipole moment and isotropic nmr determinant and in this work we usedgaussian 03 at nmr and calculation by using b3lyp methods with 6-31g* basis set.

Journal: :journal of physical & theoretical chemistry 2014
jamileh shakibayifar karim zare

the methamphetamine has been studied theoretically at the mp2 [1]/6-31g[2] level in gas phase.methamphetamine has been investigated via nmr, frequencies calculation and nbo analysis. thestructure of methamphetamine was designed primarily using of chem. bio draw and it geometry hasbeen optimized at the mp2/6-31g computational level. the present work consists the study of themethamphetamine repor...

Journal: :Dalton transactions 2009
Bhaswati Ghosh Mukhopadhyay Suman Mukhopadhyay M Fátima C Guedes da Silva M Adília Januário Charmier Armando J L Pombeiro

Reactions of the aminoiminophenols 2-((2-(dimethylamino)ethylimino)methyl)phenol (HL(1)) or 2-{(3-(dimethylamino)propylimino)methyl}phenol (HL(2)) with nickel(II) chloride, K(2)[PtCl(4)] or copper(II) acetate in alcoholic solution, in the absence or in the presence of sodium azide, afford the corresponding new mononuclear complexes [M(L(1))(X)(H(2)O)(n)] [M = Ni, X = Cl(-), n = 2 (); M = Ni, X ...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید