Correlation through space

There are basically three main types of 2D NMR experiments J-resolved, shift correlation through bonds (e.g., COSY), and shift correlations through space e.g., NOESY). These spectra may be of homonuclear or heteronuclear type involving interactions between similar nuclei (e.g., protons) or between different nuclear species (e.g., H with C). 

Exchange peaks correlate one molecule with a different molecule, whereas NOE peaks correlate through space within the same molecule. The NMR timescale for this exchange (AS = 5.11-4.54 = 0.57 ppm Av = 0.57 x 500 = 285 Hz) can be calculated as 1/(2.22 x Av) = 1.58 ms. Because we see sharp peaks for the glucose-1 resonances of both forms of lactose, the lifetime of each state must be much longer than 1.58 ms. 

Section 6-3 Proton-Proton Correlation Through Space or Chemical Exchange 195... 

Correlations through space The nuclear Overhauser effect... 

Claridge TDW (1999) Correlations Through Space The Nuclear Overhauser Effect. In Baldwin JE, Williams RM (eds.) High-Resolution NMR Techniques in Organic Chemistry, Vol. 19, p. 277. Elsevier Science, Oxford, UK... 

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