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Couplings, heteronuclear long-range

The H-NMR and C-NMR chemical shifts have been assigned and substractures have been deduced on the basis of COSY-45° (Problem 5.13) and other spectroscopic observations. Interpret the HMBC spectrum and identify the heteronuclear long-range coupling interactions between the H and C nuclei. [Pg.295]

The selective heteronuclear /-resolved experiment (Bax, 1984) is used to determine heteronuclear long-range coupling constants via a selecdve n pulse that causes splitting of all carbon signals coupled to that proton. [Pg.372]

Kurz, M., Schmieder, P., Kessler, H. HETLOC, an efficient method for determining heteronuclear long-range couplings with heteronuclei in natural abundance. Angew. Chem. Int. Ed. 1991, 30,1329-1331. [Pg.249]

Fig. 1. Pulse sequences modified for multiple selective excitation. I ID TOCSY, II het-eronuclear ID NOE, III ID INADEQUATE, IVa heteronuclear ID COSY (optimized to detect Jch), IVb heteronuclear ID COSY (optimized to detect "Jch), V 2D TOCSY-COSY, Via 2D HMBC (designed to detect heteronuclear long-range couplings "Jch only), VIh 2D HMBC (extended pulse sequence to detect both heteronuclear long-range "Jch and... Fig. 1. Pulse sequences modified for multiple selective excitation. I ID TOCSY, II het-eronuclear ID NOE, III ID INADEQUATE, IVa heteronuclear ID COSY (optimized to detect Jch), IVb heteronuclear ID COSY (optimized to detect "Jch), V 2D TOCSY-COSY, Via 2D HMBC (designed to detect heteronuclear long-range couplings "Jch only), VIh 2D HMBC (extended pulse sequence to detect both heteronuclear long-range "Jch and...
Heteronuclear NOE experiments yield additional, but due to their inherent low sensitivity only sparsely exploited information on molecular structures. They are most useful to unravel structural features in the vicinity of quaternary carbons often behaving as barriers when exposed to standard routine experiments dedicated to evaluate coupling networks. Heteronuclear NOE data - in some sense complementary to the data from heteronuclear long-range couplings - are based on dipolar spin-spin interactions and strongly depend on intemuclear distances. In contrast to the sometimes similar Jch... [Pg.31]

While heteronuclear long-range couplings are generally fairly uniform, the... [Pg.413]

Cicero DO, Barbato G, Bazzo R. Sensitivity enhancement of a two-dimensional experiment for the measurement of heteronuclear long-range coupling constants, by a new scheme of co- 81. herence selection by gradients. J. Magnet. Reson. 2001 148 209-213. [Pg.1290]

Heteronuclear-homonuclear-heteronuclear Hartmann-Hahn spectroscopy Determination of heteronuclear long-range couplings... [Pg.240]

K. Furihata, M. Tashiro, H. Seto, High resolution-HMBC (HR-HMBC), a new method for measuring heteronuclear long-range coupling constants, Magn. Reson. Chem. 48 (2010) 179-183. [Pg.229]

In the comprehensive review Kato et al summarized recent development of NMR methods for characterizing the dynamic conformations and interactions of oligosaccharides including also stable isotope labelling process. Heteronuclear long-range coupling constants from... [Pg.430]

COSY = homonuclear chemical shift correlation spectroscopy NOESY = 2D nuclear Overhauser effect (NOE) spectroscopy HMQC = heteronuclear mulltiple-quantum coherence RELAY = relayed coherence transfer COLOC = correlation via long-range coupling HMBC = heteronuclear long-range coupling INADEQUATE = incredible natural abundance double quantum transfer experiment. [Pg.156]

See other pages where Couplings, heteronuclear long-range is mentioned: [Pg.295]    [Pg.296]    [Pg.299]    [Pg.312]    [Pg.318]    [Pg.323]    [Pg.350]    [Pg.37]    [Pg.39]    [Pg.42]    [Pg.671]    [Pg.227]    [Pg.232]    [Pg.20]    [Pg.215]    [Pg.83]    [Pg.208]    [Pg.234]    [Pg.238]    [Pg.200]    [Pg.235]    [Pg.600]    [Pg.258]    [Pg.221]    [Pg.515]    [Pg.147]    [Pg.1089]    [Pg.198]   
See also in sourсe #XX -- [ Pg.175 ]



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