Proton Spin-Coupling Constants

Source Compiled by Varian Associates. Absolute values. Reproduced with permission. 

---

TABLE 7.46 Proton Spin Coupling Constants (Continued)... 

Some carbon-13-proton spin coupling constants of dimethyl N,N-dimethylaminomethylenemalonate were determined (90IZV356). 

V. F. Bystrov and A. U. Stepanyants, The stereochemical significance of the long-range proton spin coupling constant of the a-fragment H-C-C-C-H, J. Mol. Spectrosc., 21 (1966) 241-248. 

Matsumori, N., Kanono, D., Murata, M., Nakamura, H., and Tachibana, K. (1999). Stereochemical determination of acyclic structures based on carbon-proton spin-coupling constants. A method of configuration analysis for natural products. J. Org. Chem. 64, 866-876. 

Turning now to some examples of energy calculations, the equilibrium between the -20-epimers of the 5a-pregnane-3j3,20-diols (6) was studied. The published proton spin coupling constants agreed... 

Geminal and vicinal proton-proton spin coupling constants in alkanes have been determined long ago and are described in any standard NMR textbook The geminal coupling constant in alkanes is negative and averages to —13 Hz, whereas for... 

Bugge, A., B. Gestoblom, and O. Hartmann. 1970. Long-range proton-proton spin coupling constants in thienothiopbenes. Acta Chem Scand 24 105. 

The proton spin-coupling constants in a number of cycloalkenes, including cyclo-hexa-1,3-diene and cyclohexene, have been calculated using a finite-perturbation INDO method and with a geometry taken from electron diffraction studies. For cy-clohexa-1,3-diene the following values (in Hz) were calculated, with experimental values in parentheses 1. 63 (9.64) 3, 1.7 (1.02) 1.8 (1.12) J2 3, 6.3 (5.04) for... 

FIGURE 2.2. The dependence of the proton-proton spin coupling constants on the dihedral angle using different forms of the Karplus equation. 

---