Indirect Determination of J and T₁ by an NMR Spin‐Echo Method

H. S.

Gutowsky

,

R. L.

Vold

, and

E. J.

Wells

, , (), and prior work cited therein.

H. Y.

Carr

and

E. M.

Purcell

, , ().

The experimental techniques are those described by

A.

Allerhand

and

H. S.

Gutowsky

, , ().

A.

Allerhand

and

E.

Thiele

, , (); we thank the authors for sending us a preprint.

S.

Binsch

,

J. B.

Lambert

,

B. W.

Roberts

, and

J. D.

Roberts

, , ().

W. B.

Moniz

and

H. S.

Gutowsky

, , ().

We have, however, observed modulation of the echo train in similar systems.⁸ The modulation is eliminated by making the pulse separation small with respect to the spectral parameters. No modulation was observed in the case of 2‐fluoropyridine because $T1N$ is so short that the $tcp$ at which an echo train could be observed for it is sufficiently short to remove the modulation.

N. Boden, J. Deck, and H. S. Gutowsky (unpublished results).

We wish to thank R. L. Vold for his assistance with the calculations.

J. A.

Pople

, , ().

M.

Suzuki

and

R.

Kubo

, , ().

When $TIX$ is too short for use of the spin‐echo method described here, $|JAX|$ in $AnX$ systems may be obtained by direct measurement of $T1A,$ $T2A,$ and $T1X$ as described by A. Abragam, Principles of Nuclear Magnetism (Oxford University Press, London, 1961), p. 331;

J.

Winter

, , ().