On June 1, 2011, Danila, Ion; Riobe, Francois; Piron, Flavia; Puigmarti-Luis, Josep; Wallis, John D.; Linares, Mathieu; Agren, Hans; Beljonne, David; Amabilino, David B.; Avarvari, Narcis published an article.Electric Literature of 75449-26-2 The title of the article was Hierarchical Chiral Expression from the Nano- to Mesoscale in Synthetic Supramolecular Helical Fibers of a Nonamphiphilic C3-Symmetrical π-Functional Molecule. And the article contained the following:
The controlled preparation of chiral structures is a contemporary challenge for supramol. science because of the interesting properties that can arise from the resulting materials, and here we show that a synthetic nonamphiphilic C3 compound containing π-functional tetrathiafulvalene units can form this kind of object. We describe the synthesis, characterization, and self-assembly properties in solution and in the solid state of the enantiopure materials. CD measurements show optical activity resulting from the presence of twisted stacks of preferential helicity and also reveal the critical importance of fiber nucleation in their formation. Mol. mechanics (MM) and mol. dynamics (MD) simulations combined with CD theor. calculations demonstrate that the (S) enantiomer provides the (M) helix, which is more stable than the (P) helix for this enantiomer. This relationship is for the first time established in this family of C3 sym. compounds In addition, we show that introduction of the “wrong” enantiomer in a stack decreases the helical reversal barrier in a nonlinear manner, which very probably accounts for the absence of a “majority rules” effect. Mesoscopic chiral fibers, which show inverted helicity, i.e. (P) for the (S) enantiomer and (M) for the (R) one, have been obtained upon reprecipitation from dioxane and analyzed by optical and electronic microscopy. The fibers obtained with the racemic mixture present, as a remarkable feature, opposite homochiral domains within the same fiber, separated by points of helical reversal. Their formation can be explained through an “oscillating” crystallization mechanism. Although C3 sym. disk-shaped mols. containing a central benzene core substituted in the 1,3,5 positions with 3,3′-diamido-2,2′-bipyridine based wedges have shown peculiar self-assembly properties for amphiphilic derivatives, the present result shows the benefits of reducing the nonfunctional part of the mol., in our case with short chiral isopentyl chains. The research reported herein represents an important step toward the preparation of functional mesostructures with controlled helical architectures. The experimental process involved the reaction of [2,2′-Bipyridine]-3,3′-diamine(cas: 75449-26-2).Electric Literature of 75449-26-2
The Article related to hierarchical chiral expression nanoscale mesoscale synthetic supramol helical fiber, Physical Organic Chemistry: Optical Rotatory Dispersion and Circular Dichroism and other aspects.Electric Literature of 75449-26-2