banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Quasiequilibrium states in thermotropic liquid crystals studied by multiple-quantum NMR
Rent this article for
View: Figures


Image of FIG. 1.
FIG. 1.

Dipolar signals after the JB experiment and Zeeman signals (dotted) in (a) nematic 5CB and (b) powder adamantane, at and . In (a), dipolar (solid) corresponds to a preparation time and dipolar (dashed) to . In (b), several dipolar signals corresponding to different . Vertical lines indicate the times of maximum and zero -order.

Image of FIG. 2.
FIG. 2.

Radio frequency pulse sequence used to encode coherences of the spin states at time after the JB pulse pair, on the and bases. Phases and were incremented from zero to in steps of to encode up to eight quantum coherence in both bases. is set short enough to minimize evolution during this period. Setting before the last 45° readout pulse sufficiently long, undesired transient signals are allowed to decay. The signal corresponds to 5CB prepared in a state of dipolar order, , , and .

Image of FIG. 3.
FIG. 3.

and basis correlated coherence numbers at short evolution times after the JB pulse pair before the establishment of the quasiequilibrium states in (a) powder adamantane, (b) nematic 5CB prepared in the condition, and (c) 5CB prepared in the condition.

Image of FIG. 4.
FIG. 4.

Evolution of the coherence amplitudes for times after the JB pulse pair projected on and bases. (a) Powder adamantane, (b) 5CB prepared in the condition, (c) 5CB in the condition, and (d) same as (c) in the range of .

Image of FIG. 5.
FIG. 5.

and basis projections of the coherence spectra [(a) and (b)] at and (c) at . Powder adamantane (a) and 5CB in the state (b) have similar shapes, while 5CB in the state (c) show a completely different composition.

Image of FIG. 6.
FIG. 6.

Relaxation of the MQ coherences encoded on the basis, starting from dipolar order in (a) powder adamantane , (b) 5CB condition , and (c) 5CB condition , at and . Inset in (b) shows relaxation of coherence observed in 5CB under the condition.

Image of FIG. 7.
FIG. 7.

Dipolar relaxation time vs coherence numbers in powder adamantane (solid diamond), 5CB (solid circle), and (open circle) order at and .


Article metrics loading...


Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Quasiequilibrium states in thermotropic liquid crystals studied by multiple-quantum NMR