Nanostructuring with chirality: binaphthyl-based synthons for the production of functional oriented nanomaterials

Abstract

Chirality is a powerful tool for the generation of order, directionality, and, as such, of function, in assembled nanoscale chemical devices. Axially chiral binaphthyls have been widely used in organic synthesis; the stability of the enantiomers enables their use as robust chirality inducers and catalysts in asymmetric reactions, and they are nowadays industrially applied in a variety of organic transformations. Applications of these compounds in the field of nanosciences are more recent, and not yet fully explored. The integration of such a robust class of chiral compounds, capable of efficient transfer of stereochemical information, into functional aggregates and nanoarchitectures is of great current interest. We will discuss preeminent examples of applications of these synthons in several fields of nanoscience, such as reticular chemistry, non-linear optical materials and imaging, and liquid crystals.

Synthesis of New Chiral Benzimidazolylidene–Rh Complexes and Their Application in Asymmetric Addition Reactions of Organoboronic Acids to Aldehydes

“…Their applicability in the asymmetric arylation of aromatic aldehydes has been demonstrated, and the corresponding diarylmethanols were obtained with high yields and moderate enantiomeric excesses (up to 46%). Further work is in progress to utilize these complexes in asymmetric 1,2-addition reactions of arylboronic acids with ketones, as well as their applications in fields of nanoscience [39,40].…”

Chiral Buckybowl Molecules

“…Their preorganized binding sites can recognize optically active molecular species selectively via noncovalent interactions and gave a conformationally stable chiral organic structures. Furthermore, essential molecular chiral components amplify to form 3D supramolecularly assembled architectures and oriented nanoscale assemblies [111,112]. The nanoscale chirality of these 3D chiral supramolecular assemblies has potential application in functional soft materials.…”

Synthesis of Binaphthyl-Based Push-Pull Chromophores with Supramolecularly Polarizable Acceptor Ends

“…On the other hand, molecular chirality offers simple design principles for push-pull and noncentrosymmetric molecules, and the nanostructuring via self-assembly of chiral organic dyes has been shown to have pronounced effects and amplifications of their SHG response [9]. Binaphthyl compounds have been exploited for the realization of second-order nonlinear optical (NLO) materials, having the combined advantages of being chromophores and carrying the required element of chirality for bulk anisotropy [10][11][12][13][14][15][16][17]. In fact, binaphthyl systems, such as that shown in Figure 1, are composed of two chromophores joined through an aryl-aryl bond, which is the element (axis) of chirality, with dihedral angles usually close to 90 ∘ , so that interchromophoric conjugation is not efficient.…”

“…The application of the binaphthyl compounds in the field of nanosciences is recent and not yet fully explored [18][19][20][21][22][23][24][25][26][27][28][29]. In all previously reported examples of binaphthyl dyes for NLO applications, the molecular design expressing the push-pull concept was developed by placing electron donating groups in the 2,2 positions and the electron accepting units in the 6,6 positions ( Figure 1) [10][11][12][13][14][15][16][17].…”