Solution NMR measurements

Tjandra N and Bax A 1997 Solution NMR measurement of amide proton chemical shift anisotropy in N-15-enriched proteins. Correlation with hydrogen bond length J. Am. Chem. Soc. 119 8076-82... 

Diethyl acetylenedicarboxylate with 2,3-diaminoquinoxaline (462) in methanol gave pyrazino[2,3-6]quinoxaline (463), which exists as the tautomer 464 in the solid state. In solution, NMR measurements show that a tautomeric mixture of both 463 and 464 is present.435... 

Table 19.8. °Io H/D exchange in lysozyme in the crystalline state (neutron diffraction) and in solution (NMR measured after 6 weeks) [641]...

One way to check whether the cross polarization method is responsible for introducing errors in aromaticity measurements, is to perform experiments using single pulse excitation in much the same way as solution NMR measurements are made. This method is time... 

NMR measurement of solvent self-diffusion coefficients in polymer solutions NMR measurement of protein diffusion coefficients in solution and in synthetic membranes... 

Table 1. References to solution NMR measurements on, and X-ray structures of, [Rli6(CO)i6] and related homo- and heterometallic derivatives.

Tjandra N, Bax A (1997) Solution NMR measurement of amide proton chemical shift anisotropy in N-ebmiched proteins. Corrrelation with hydrogen bond length. J Am Chem Soc 119 8076-8082 Tossell JA (1984) Correlation of Si NMR chemical shifts in sihcates with orbital energy differences obtained from x-ray spectra. Phys Chem Mineral 10 137-141 Tossell JA (1992) Calculation of the Si NMR shielding tensor in forsterite. Phys Chem Mineral 19 338-342... 

In the assignment of the roethine carbon resonances in the E-VOH copolymers we have to take in account both tacticity effects, as in PVOH, and sequence distribution effects. For the calculation of the chemical shifts in the sequence triads of solid E-VOH copolymer, the chemical shift additivity rules for aliphatic alcohols, as calculated by Ovenall [5] from solution NMR measurements, have been used ... 

The solution of NMR measurements were recorded at 200 MHz on a Varian XL-200 NMR spectrometer. Solution NMR measurements were recorded at 67.5 MHz on a Bruker WP-270 SY NMR spectrometer. Differential scanning calorimetry (DSC) was performed using the Perkin-Elmer Model DSC-2C. 

Cobalt-59 NMR data has been recorded for a wide range of complexes (305,362,541,1395,1396), many examples of which are included in a review of this topic (1397). Since Co NMR chemical shifts cover a wide range, this allows identification of mixed-ligand species. Bond et al. (541) noted that Co NMR chemical shifts do not correlate in a simple fashion with electrochemical data (see below), suggesting that steric effects influence the two techniques in a different way. A second study by the same group used both solution and solid-state C NMR spectroscopy and solution NMR measurements to show that the increase in ligand-field strength associated with phenyl substituents is due to a combination of steric and electronic effects (359). 

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