Studies on Cycloalkane‐Based Bisamide Organogelators: A New Example of Stochastic Chiral Symmetry‐Breaking Induced by Sonication

Abstract

Enantiomerically pure C -alkyl amides derived from cis and trans cycloalkane-1,2-dicarboxylic acids, respectively, have been synthesized and their behavior as organogelators has been investigated. These compounds include cis/trans diastereomeric cyclobutane and cyclohexane derivatives with the aim to explore the influence of the ring size as well as the relative configuration in their hierarchical self-assembly to form gels. High resolution H NMR spectroscopy studies allowed the determination of the dynamics of the gelation process in [D ]toluene and the sol-gel transition temperature. The morphology and size of the aggregates have been investigated and results have shown that, in the case of cyclobutane derivatives, the cis/trans stereochemistry is not relevant for the gelation behavior and the properties of the soft-materials obtained, but it is remarkable for cyclohexane diamides, which are better organogelators. The four compounds produce chiral aggregates despite that two of them are meso achiral molecules. We show herein that this fact is an example of stochastic symmetry breaking induced by sonication. The self-assembly of these molecules has been modelled providing information and support about the structure and the chirality of the aggregates.

Synthesis and Gelling Abilities of Polyfunctional Cyclohexane-1,2-dicarboxylic Acid Bisamides: Influence of the Hydroxyl Groups

“…Compounds cis - and trans - 2 , 3 and 4 were soluble in water whereas 5 was insoluble; formation of hydrogels was not observed in any case. Results for organic solvents are summarized in Table 1 where data for related compounds cis - and trans - 1 [24] are also shown for comparison.…”

“…In addition, cis - 2 also promotes the formation of gels in pentane, ethyl acetate and isopropanol although with higher mgc (minimum gelation concentration) values. Nevertheless, the differences between these diastereoisomers are not very remarkable in contrast with the behavior of isomers 1 , being trans - 1 a much better gelator than the cis diastereomer (Table 1) [24].…”

“…In both cases, a model to explain the self-assembly of the individual molecules to produce the gel was suggested by means of computational calculations. More recently, we reported a combined experimental and computational study to investigate and rationalize the gelling ability of diastereomeric 1,2-disubstituted carbocyclic compounds ( 1 , Figure 1) [24]. The influence of the cis / trans relative configuration of the monomers in their hierarchical self-assembly was analyzed and their gelling behavior compared well with that of trans -cyclohexane-1,2-diamine derivatives described by Hanabusa et al [25] and van Esch et al [26] suggesting that regiochemistry does not play a relevant role in the gelation process.…”

The Chain of Chirality Transfer as Determinant of Brain Functional Laterality. Breaking the Chirality Silence: Search for New Generation of Biomarkers; Relevance to Neurodegenerative Diseases, Cognitive Psychology, and Nutrition Science

“…The phase transitions were shown to be implicated in the effects of the chirality transformation and monochirality observed in the amino acids and proteins [119]. XVIII The sonication-induced chiral symmetry breaking events were observed during sol-gel phase transition [129]. XIX The quantum fluctuations are associated with Heisenberg's uncertainty principle.…”

The Topological Variable Computation for a Special Type of Cycloalkanes

“…More contexts on cycloalkanes and its applications can refer to El-Sayed et al [30], Vásquez-Espinal et al [31], Caroen et al [32], Denicourt-Nowicki et al [33], El-Gamal et al [34,35], Lepori et al [36], Nambu et al [37], Lazić et al [38], Alaoui et al [39], and Pi-Boleda et al [40]. Since cycloalkanes commonly appeared in the chemical compound and possess wide engineering applications in the field of biology, medicine, and pharmacy, it inspires us to study the characterization of cycloalkanes from mathematical point of view.…”