Single experiment measurement of residual dipolar couplings in aqueous solution using a biphasic bisperylene imide chromonic liquid crystal

Abstract

The use of the biphasic isotropic/nematic region in a bisperylene imide‐based lyotropic liquid crystal system allows the extraction of proton‐carbon 1DCH residual dipolar couplings in aqueous solution from a single F1‐coupled HSQC experiment. The method was successfully applied to the RDC‐based conformational analysis of sucrose.

A supramolecular and liquid crystalline water‐based alignment medium based on azobenzene‐substituted 1,3,5‐benzenetricarboxamides

“…This approach has previously been reported for other alignment media, for example, bicelles, [ 47,72 ] and more recently chromonic phases. [ 41,42 ]…”

“…This approach has previously been reported for other alignment media, for example, bicelles, [47,72] and more recently chromonic phases. [41,42] F I G U R E 4 1 D CÀH residual dipolar couplings (RDCs) from temperature series for sucrose (4) and sodium cholate (5) (for numbering, see SI) (300 to 350 K and back again, only selected couplings for sodium cholate, both at 600 MHz proton frequency). Slight differences in RDCs displayed compared with Table 1 are reasoned in the usage of different spectrometers (working also at different proton frequencies/magnetic field strengths)…”

“…Because BTA self-assembly is, however, also well known from polar environments, [23,[30][31][32][33] we were wondering if anisotropic phases formed under these conditions might be suitable as alignment media as well, which would further amplify the repertoire of water-compatible alignment media available. [1,[34][35][36][37][38][39][40][41][42][43] Particularly, our interest fell onto the results originally presented by Wang et al, [23] describing an LLC based on a BTA with azosulfonic acid sidechains in water (Figure 1, BTA 1a). Compared with recent work in the field of supramolecular alignment media, [41,42] the main difference is that in contrast to chromonic LLCs, which usually form both a nematic and a hexagonal phase depending on the concentration used, [44,45] for the system used here, only a hexagonal phase is known.…”

“…[1,[34][35][36][37][38][39][40][41][42][43] Particularly, our interest fell onto the results originally presented by Wang et al, [23] describing an LLC based on a BTA with azosulfonic acid sidechains in water (Figure 1, BTA 1a). Compared with recent work in the field of supramolecular alignment media, [41,42] the main difference is that in contrast to chromonic LLCs, which usually form both a nematic and a hexagonal phase depending on the concentration used, [44,45] for the system used here, only a hexagonal phase is known. [23] If this system could successfully be applied as alignment mediumdespite the high viscosity expected for hexagonal phasesit would fundamentally extend the range of application for BTA-based media by enabling measurements also under polar conditions.…”

“…Because BTA self‐assembly is, however, also well known from polar environments, [ 23,30–33 ] we were wondering if anisotropic phases formed under these conditions might be suitable as alignment media as well, which would further amplify the repertoire of water‐compatible alignment media available. [ 1,34–43 ]…”