The Dependence of the Polarity of Solvents on 1,3 : 2,4-Di-O-benzylidene-d-sorbitol Gel

Abstract

1,3 : 2,4-Di-O-benzylidene-d-sorbitol (d-DBS) is known as a chiral oil gelator for a wide variety of organic solvents. The relationship between texture, structure of the gel, and the aggregated structure formed by d-DBS was investigated in various solvents. In the low polar solvents, the gel held a mesh type network structure in which the fiber appeared to be a rope-like helical structure. In the moderately polar solvents, the gel held an isotropic mesophase, but in the polar solvents, a spherulite texture was observed. From the experiments for the critical gel concentration of d-DBS in various solvents, it is assumed that there are three regions that differ in the form of hydrogen bonding, depending upon the polarity of solvents. By IR spectroscopic measurements, we found that, with the increase of solvent polarity, the hydrogen bonding between d-DBS and the solvent became more predominant than the intramolecular hydrogen bonding, and the hydrogen bonding between d-DBS became weaker at the same time. In addition, the intensities of CD spectra in the d-DBS gel decreased according to the increase of the solvent polarity. Here it is considered that textures and structurs observed in the gel are related to the aggregated structure that is mainly formed through hydrogen bonding among d-DBS.

1,3:2,4-Dibenzylidene-d-sorbitol (DBS) and its derivatives – efficient, versatile and industrially-relevant low-molecular-weight gelators with over 100 years of history and a bright future

“…36 For the alternative energy-minimized conformations of DBS, it was found that p-p interactions (between phenyl groups in the equatorial position) were also present, in some agreement with the results of Watase. With respect to intermolecular interactions, they found that for the initial energy-minimized configuration of DBS, the only interaction in the dimer was the formation of a hydrogen bond between the 6-OH group of one DBS molecule and an acetal oxygen of the other -in agreement with the model proposed by Yamasaki.…”

“…36 They reacted L-glucono-1,5-lactone with two equivalents of benzaldehyde dimethyl acetal to first yield the intermediate 3,5:4,6-dibenzylidene-L-gluconic acid. Yamasaki and co-workers reported an interesting alternative approach to the 5-methoxy derivative of DBS based on the use of different starting materials.…”

“…36 In low polarity solvents, intra-and intermolecular H-bonding of DBS was favoured, whilst in high polarity solvents, H-bonding between DBS and the solvent, which does not underpin gel assembly, became favoured and the compound dissolved. They explored the impact of different possible hydrogen bonds on DBS self-assembly.…”

Polyaniline-poly(styrene sulfonate) conducting hydrogels reinforced by supramolecular nanofibers and used as drug carriers with electric-driven release

“…The supramolecular self-assembly of DBS has been extensively investigated. A common conclusion is that DBS is capable of self-assembly into a 3D nanofiber network [26][27][28]. We observed that DBS nanofibers and PANI-PSS chains entangle each other, leading to the formation of dual interpenetrated networks and thereby reinforcing the hydrogels.…”

Electrically controlled light scattering from thermoreversible liquid-crystal gels

“…2,3 It is known to cause gelation in the semidilute concentration range ͑Ӷ5%͒ in a great variety of liquids ranging from chloroform 4 to ethylene glycol 5 and siloxanes. 6 Gel formation in these solvents is attributed to an association of DBS molecules into well-ordered helical aggregates 2 that interwind to form a submicron scale three-dimensional network, turning the solutions into viscoelastic solids.…”