نتایج جستجو برای: 2d nmr

تعداد نتایج: 138579  

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2006
Tamar Evan-Salem Inbal Baruch Liat Avram Yoram Cohen Liam C Palmer Julius Rebek

The host-guest complexes of resorcin[4]arenes with small molecules in organic solutions are examined using modern NMR spectroscopic methods. The complexation of glutaric acid and beta-methyl d-glucopyranoside in chloroform were investigated through 2D COSY, 2D NOESY, 1D NOE, and diffusion-ordered NMR spectroscopy (DOSY) techniques. These methods indicate that the complex is a self-assembled cap...

Journal: :Journal of magnetic resonance 2003
Boaz Shapira Lucio Frydman

We have recently demonstrated that magnetic field gradients in combination with frequency selective pulses, can be employed to collect a complete multi-dimensional NMR spectrum within a single scan. Following similar guidelines, field gradients could also be exploited to parallelize other types of NMR experiments where the final results arise from the collection and analysis of a series of time...

2008
Sylvian Cadars Nicolas Mifsud Anne Lesage Jan Dirk Epping Niklas Hedin Bradley F. Chmelka Lyndon Emsley

Surfactant-templated layered silicates are shown to possess complex compositional, structural, and dynamic features that manifest rich and interrelated order and disorder at molecular length scales. Temperature-dependent 1D and 2D solid-state 29Si NMR measurements reveal a chemical-exchange process involving the surfactant headgroups that is concomitant with reversible broadening of 29Si NMR li...

2012
Bernd Wrackmeyer Klaus Schamel Karlheinz Guldner

Laboratorium für Anorganische Chemie der Universität Bayreuth, Postfach 101251, D-8580 Bayreuth Z. Naturforsch. 42b, 703-706 (1987); received January 15, 1987 Reverse 2D 'H{N} NMR Spectra, Phosphane Complexes, Inorganic Ring System PS2N3, X-Ray The inorganic ring system RPNSNSNH linked to the [Cr(CO)5] fragment [R = T3u (1), NH2 (2)], has been studied by reverse two-dimensional, 2D , 'H{N} NMR ...

Journal: :Planta medica 2013
Ki Hyun Kim Eunjung Moon Sun Yeou Kim Sang Un Choi Mi Won Son Sang Zin Choi Kang Ro Lee

A phytochemical investigation on the essential oil of Thuja orientalis resulted in the isolation and identification of three new sesquiterpenes, 3α-methoxy-4α-epoxythujopsane (1), Δ³,¹⁵-4β-epoxythujopsene (2), and Δ³,⁴-thujopsen-2,15-diol (3), together with eight known sesquiterpenoids (4-11). The structures of these new compounds were elucidated based on spectroscopic data analyses including e...

Journal: :Chemical & pharmaceutical bulletin 2004
Chun-Suo Yao Li-Xin Zhou Mao Lin

Four new compounds 1-4 were obtained from an oxidative coupling reaction of (E)-isorhapontigenin using FeCl(3) as oxidant. Their structures and stereochemistry were determined on the basis of spectroscopic evidence [UV, IR, MS, (1)H-, (13)C-NMR, NOE and 2D NMR], and their possible formation mechanisms were also discussed, respectively.

2014
Nurdin Saidi

Two aphorpine alkaloids, (+)-lirinine 1 and (+)-lirioferine 2 and two bezylisoquinoline alkaloids (+)reticuline 3 and (-)-N-Methylisococlaurine 4 were isolated from bark of Cryptocarya crassinervia. The structures were elucidated by spectral analysis, including 1D-NMR (H, C, DEPT), 2D-NMR (COSY, HMQC, HMBC), UV, IR, and MS and comparison with the published data.

2015
Tahira Moeen Khan

A New pregnane type Alkaloid named Sracosalgminol [(20S)-20-(dimethylamino)-3β-methoxy-16β-hydroxyl-pregn-5-ene] was isolated from sarcococca saligna and its structure was established on the basis of spectroscopic techniques includingH,13C-NMR and inverse 2D-NMR techniques (DEPT,HMQC and HMBC) UV,MS etc.

Journal: :Chemical communications 2014
Yuting Wu Carmine D'Agostino Daniel J Holland Lynn F Gladden

We demonstrate the application of Compressed Sensing-NMR to decrease the data acquisition time of 2D COSY NMR from >5 h to ∼1.5 h such that the kinetics of a reaction are followed, along with identification of intermediate and product species.

2015
Tahira Moeen Khan Ismat Naeem

A New Alkaloid named Sracosalgnenone [ (20S) -20(dimethylamino) -3β-tigoloyl-pregn-5, 16-diene-4-one] was isolated from sarcococca saligna and its structure was established on the basis of spectroscopic techniques includingH, C-NMR and inverse 2D-NMR techniques (DEPT, HMQC and HMBC) UV, MS etc.

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