AI Article Synopsis
- Researchers used solid-state NMR to study the conformations of differently shaped mesogens in the liquid crystalline phase.
- The mesogens examined included a rod-like structure, a three-ring core linked to a phenyl ring, and a trimesic acid with side arms.
- The study found distinct order parameter (S) values for each structure, leading to the proposal of a tripod-like conformation for the trimesic acid mesogen rather than the expected λ shape.
Article Abstract
Mesogens that vary in shape anisometry have been investigated by C solid-state NMR in the liquid crystalline phase to inspect the conformations. The molecules examined comprise of (i) rod-like mesogen with three-phenyl ring core and terminal hexyloxy chains, (ii) three-ring core linked to the fourth phenyl ring via a spacer, and (iii) trimesic acid connected to three side arms core units through a spacer. The order parameter (S ) values for the phenyl rings of the rod-like mesogen are 0.65-0.68, while the mesogen with a three-ring core linked to a phenyl ring via spacer showed dissimilarity. Consequently, for the core unit phenyl rings, S is ~0.70, and the terminal phenyl ring showed a low value of 0.12. For the trimesic acid based mesogen, the S value for the side arm phenyl rings is ~0.53, and for the central phenyl ring, a very low value of 0.11 is witnessed. By considering the ordering of the rod-like mesogen as a yardstick and employing the ratios of S values of the phenyl rings, the average conformations of other mesogens are arrived. Accordingly, for the trimesic acid based mesogen, a tripod-like conformation instead of λ shape is proposed in the liquid crystalline phase.
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| http://dx.doi.org/10.1002/cphc.202300353 | DOI Listing |
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