Theoretical calculations of isotope effects on chemical shifts and coupling constants and comparison with experimental values were used as a method of the calculation methods verification. Several papers were dedicated to this topic, mostly the review articles.32-35 [Pg.152]

Clearly, in the framework of the proposed physicochemical approach, it is impossible to theoretically predict the values of chemical constants k0 for each particular reaction couple A-B. This drawback is known to be characteristic of any phenomenological consideration. Therefore, the inverse task is exercised in practice, namely, experimentally determined kinetic dependences x - t and y - t are used to calculate appropriate constants. [Pg.87]

On the other hand, in the theoretical calculations of statistical mechanics, it is frequently more convenient to use volume as an independent variable, so it is important to preserve the general importance of the chemical potential as something more than a quantity GTwhose usefulness is restricted to conditions of constant temperature and pressure. [Pg.350]

If we remember the two very different routes which led to the theoretical calculation of chemical constants (pp. 169 and 205), we must regard it as probable— [Pg.267]

Overend and coworkers " applied the preceding theoretical relationships, permitting calculation of chemical reaction-rate constants from kinetic currents, to some monosaccharides and their derivatives. They [Pg.141]

The calculation of NMR chemical shifts has become feasible recently with improvements in both the speed and capabilities of computational chemical methods [70]. While the bulk of the theoretical work has been directed toward the calculation of chemical shifts, results for [71], [72], and hypertine coupling constants [Pg.334]

Sychrovsky, V., Sponer, J., Elobza, P. (2004). Theoretical calculation of the NMR spin-spin coupling constants and the NMR shifts allow distinguishability between the specific direct and the water-mediated binding of a divalent metal cation to guanine. Journal of the American Chemical Society, 126, 663. [Pg.1308]

SR = calculated from measured spin rotation constants in molecular beam experiments. Aik.Hal. = from theoretical calculations of shieldings in alkali halide crystals. Aik.Hal. (P) = from pressure dependence of alkali halide shifts in combination with theoretical models for shielding values. T2 = calculated from experimental value of line width at infinite dilution. 6VS.T2 = calculated from concentration dependence of chemical shifts and line widths. H2O/D2O = calculated from solvent isotope effects on chemical shifts. NaVwa" = estimated from difference in chemical shift between Na and Na . Atomic beam = calculated from magnetic moment of free atom determined in atomic beam experiments. [Pg.210]

It has been possible to correlate molecular structure and stereochemistry, including parameters such as electron distributions and bond angles, to observed coupling constants. However, as is the case with chemical shifts, a firm theoretical framework for calculation of coupling constants is absent, and those semi-theoretical treatments that have been put forward must be applied with care. We will consider other aspects of spin-spin coupling in Section 4(cXii). [Pg.19]

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