Two long-range

In Problem 40 we have recorded two long-range correlation spectra using delays set for two different long-range J values, 8 and 2 Hz. The differences between the spectra give us even more structurally-relevant information. 

A further detractor from the m,n-ADEQUATE experiment is the inherent ambiguity of the two long-range magnetization transfers. As in the HMBC/GHMBC experiment, the m/ci 1 transfer step may afford... 

Aside from the initial applications of the n, 1- and m,n-ADEQUATE experiments in the elucidation of the structure of 5,6-dihydrolamellarin (3, see Sections 4.1, 5.1 and 6.5), the author is unaware of any reported applications of these experiments in the literature.38 Given the potential ambiguities associated with the two long-range magnetization transfer steps of the latter, coupled with the very low sensitivity and the fact that correlations are observed in Fi at the DQ frequency of the coupled carbons rather than at the 13C shift as in the 1,1- or 1,h-ADEQUATE experiments, it is probably quite likely that the m,n-ADEQUATE experiment will continue to be very sparingly utilized for structure elucidation. 

Candid provides two modes of constraint combination (further combination modes can be envisaged readily) 2-> 1 combination of all assignments of two long-range peaks each into a single constraint, and 4 -> 4 pair wise combination of the assignments of... 

Eq. (92) represents the difference betw n two long range potentials both having a Coulombic — 1/r behavior and it therefore decays faster than Coulombic. In the approximation ASi — As, the potential W reduces to the Slater potential Vx.scr and only the first term survives in Eq. (92). If we apply this same... 

All mentioned above is corroborated by HMBC experiments, which also can be used to discern between a and p-cycled isomers. In the a-cycled compounds appear two long range correlations between H-8 and carbonyl C-l, and H-5 and the carbonyl-C-4, while in the P-cycled only one correlation between H-8 and C-l carbonyl is observed, Fig. (5). 

Comparable errors are also contained in calculations in which the interactions between distant cells are cut off too early since in this case the partial summation of the two long range interactions (which cancel each other accurately only for infinite distance) makes the results inaccurate. 

The more elaborate MC moves have been contemplated with two long-range aims in mind ... 

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