Coupling constant data only

Abraham The structure of the imipramine hydrochloride was taken from crystal measurements combined with coupling constant data. Only the position of the benzene ring of the benzyl alcohol ligand with respect to the imipramine was obtained from the aromatic shift data considered here. 

Some typical proton and carbon chemical shift and coupling constant data for allylic and benzylic systems are given in Scheme 3.54. An alkenyl substituent or a phenyl substituent on either a CH2F or a —CHF- group has virtually no effect upon that carbon s chemical shift, and they also only affect the proton chemical shift by about 0.5 ppm. 

At present NMR chemical shift data are only available for three diene complexes, [(C4H )Fe(CO)3], [(C4He)Fe(CO)3], and [(CigHgvCH CH—CH=CHC02Me)Fe(C0)3] (see Table XXI). For the butadiene derivative 188, 192), it was felt that the chemical shift and coupling constant data are more consistent with (XII) rather than (XIII). 

Geminal C-C coupling constant data are available for a variety of compounds but, unfortunately, signs of this coupling constant have only been determined in very few instances. (29) Also, calculations of the... 

Finally, cyclohexane derivatives show different coupling constants for protons that are axial or equatorial, as indicated in Figure 14.36. Analysis of structure using coupling constants is a powerful tool, when such data are available. As indicated previously, coupling constant data will be provided occasionally with homework problems, but only for relatively simple cases (cis-, mns-alkenes, cis-, ra/ s-cyclohexanes, and some substituent patterns on benzene rings). 

The data collection exists in two versions. Only chemical shifts data are reported in the printed version of this volume. In cases where coupling constants data are given in the CD-ROM version the substance is marked by an asterisk ( ) in the column Gross formula. 

H N coupling constants, often measured in H NMR using labeled compounds, are discussed together with N NMR (Section VI,D). Taking into account that H NMR data are now present in every paper dealing explicitly or implicitly with tautomerism, only a few articles are documented in this section. 

Two isomeric structures can be obtained for these products ( -113 and/or Z-113). The stereochemistry was conveniently elucidated on the basis of NMR data which showed coupling constant values 7(H,CO) consistent with the -isomers only. The formation of 113 was explained to occur via the enolate salts (86JHC199). Catalytic... 

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