scholarly journals 1,3-Oxazepane-4,7-Diones Compounds: 1H and 13C NMR High-Resolution Spectroscopy (1D and 2D)

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
AbdulKarim-Talaq Mohammad ◽  
Hasnah Osman ◽  
Guan-Yeow Yeap

The complete 1H and 13C NMR assignment of new 1,3-oxazepane-4,7-dione compounds has been obtained using one- and two-dimensional NMR techniques including COSY, HMQC, and HMBC experiments. The data deduced from this study show that the alkyl chain and the phenyl ring are in different planes compared to the oxazepine ring.

1999 ◽  
Vol 23 (7) ◽  
pp. 414-415
Author(s):  
Adele Mucci ◽  
Luisa Schenetti ◽  
Maria A. Vandelli ◽  
Barbara Ruozi ◽  
Flavio Forni

The interaction of diclofenac sodium salt (DCFNa) and two cyclodextrins, β-cyclodextrin (βCD) and 2-hydroxypropyl-β-cyclodextrin (HPβCD), studied in D2O solution with different NMR techniques (1H, 13C NMR, ROESY experiments, NMR titrations), shows the existence of multiple equilibria involving 1:1 and 2:1 guest–host complexes.


ChemInform ◽  
2010 ◽  
Vol 23 (20) ◽  
pp. no-no
Author(s):  
J. P. SHOCKCOR ◽  
R. C. CROUCH ◽  
G. E. MARTIN ◽  
A. CHERIF ◽  
J.-K. LUO ◽  
...  

2008 ◽  
Vol 3 (1) ◽  
pp. 89-93
Author(s):  
Irina Lunga ◽  
Pavel Kintia ◽  
Stepan Shvets ◽  
Carla Bassarello ◽  
Sonia Piacente ◽  
...  

Ten steroidal saponins have been isolated form the seeds of Hyoscyamus niger L. for the first time and their structures have been elucidated. Seven saponins belong to spirostane series, two are furostane-type and one is pregnane glycoside. Hyoscyamosides B, C and C2 are new steroidal saponins, which have never been reported before in literature. Complete assignments of the 1H and 13C NMR chemical shifts for all these glycosides were achieved by means of one- and two-dimensional NMR techniques, including 1H–1H COSY, HSQC, HMBC and ROESY spectra.


1991 ◽  
Vol 69 (8) ◽  
pp. 1207-1211 ◽  
Author(s):  
Paris E. Georghiou ◽  
Chi Keung (Jimmy) Ho ◽  
Chester R. Jablonski

The 1H and 13C NMR spectra of chromotropic acid (CTA) (4,5-dihydroxy-2,7-naphthalenedisulphonic acid) have been unambiguously assigned. Proton NOED spectra were used to show the proximity of both H-3 and H-6 and the hydroxyl groups. Two-dimensional 1H–13C NMR correlation spectra of CTA, of its corresponding diacetoxy derivative, and of 3-bromo- and 3,6-dibromo-CTA support the assignments. A regioselective deuterium exchange reaction of the C-3 and C-6 protons of CTA with deuterium oxide was observed during the NMR experiments. This latter finding is strongly indicative of the mode of formation, and of the nature of the chromogen formed in the reaction of CTA with formaldehyde in the well-known CTA-formaldehyde analytical reaction. Key words: chromotropic acid, 3-bromochromotropic acid, 3,6-dibromochromotropic acid.


1990 ◽  
Vol 55 (5) ◽  
pp. 1208-1215 ◽  
Author(s):  
Pavel Hrnčiar ◽  
Tibor Liptay ◽  
Ján Šraga

3-Acyloxy-5-(2-phenylethenyl)-2-cyclohexen-1-ones II were prepared by O-acylation of 5-(2-phenylethenyl)-1,3-cycloxanedione (I). Treatment of II with AlCl3 resulted in rearrangement of the acyl group to the double bond of the phenylethenyl grouping followed by cyclization to 8-acyl-7-phenylbicyclo[2.2.2]octane-2,6-diones III. Their structure was evidenced by analysis of the 1H and 13C NMR spectral data.


1999 ◽  
Vol 72 (5) ◽  
pp. 844-853 ◽  
Author(s):  
Seiichi Kawahara ◽  
Saori Bushimata ◽  
Takashi Sugiyama ◽  
Chihiro Hashimoto ◽  
Yasuyuki Tanaka

Abstract A novel analytical method using high resolution 13C-NMR spectroscopy to study polymer latex, which is a heterogeneous system comprising polymer dispersoid and water, is described. The appropriate concentrations of surfactant and dried rubber content of a polybutadiene latex, which give the best spectrum, were found to be 1 w/v % and 10%, respectively. The half-widths of resonance peaks for the latex sample were almost identical to the half-widths obtained in solution, which were about one-third the width of those obtained using a solid sample of either a crosslinked or soluble polybutadiene. Nevertheless, the signal to noise ratio for the latex sample was slightly smaller than that for the solution sample. The values of spin-lattice relaxation time, T1, for the latex sample were similar to those for the solid sample. These demonstrate that the latex state C-NMR spectroscopy will be a powerful technique for structural characterization of crosslinked gels in the dispersoid because it gives a high resolution spectrum comparable to solution state spectroscopy, showing short T1 values corresponding to those for solid state C-NMR spectroscopy. High resolution latex state 13C-NMR spectroscopy was used to determine the concentrations of the various isomers of the polybutadiene in the dispersoid.


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