Two-Dimensional Folded Nanosheets Lead to an Unusual Circular Dichroism Effect in Aqueous Solution

We found that two-dimensional (2D) folded nanosheets with crystalline structure in aqueous solution could induce an unusual time-dependent circular dichroism (CD) effect in the CD measurements after shaking or stirring the solution. In addition, a critical damping curve was observed in the CD spectrum after stop of stirring the solution. The apparent CD effect actually originates from linear dichroism (LD) changes in the oscillations of two-dimensional folded nanosheets and the inherent optical imperfections of the CD instruments. The oscillations of the folded nanosheets should induce this CD effect by the conformational change. Although an unusual apparent CD effect in alignment of one-dimensional (1D) dye-containing supramolecular nanofibers has been documented, this study reports for the first time that 2D folded nanosheets can lead to such a CD effect. It is anticipated that the method may provide a way to spectroscopically visualize the dynamic conformational change of self-assemblies in solutions

<i>p</i>‑Toluenesulfonohydrazide as Highly Efficient Initiator for Direct C–H Arylation of Unactivated Arenes

<i>p</i>-Toluenesulfonohydrazide (PTSH) was shown to promote the highly efficient direct arylation of unactivated arenes with aryl iodides, bromides, or chlorides in the presence of potassium <i>tert</i>-butoxide without the assistance of any transition metals. The reaction proceeds through base-promoted homolytic aromatic substitution (BHAS) involving aryl radicals and arylradical anions as intermediates

Supramolecular Hydrogels Fabricated from Supramonomers: A Novel Wound Dressing Material

Daily repeated wound dressing changes will lead to additional trauma to newly formed tissue and prolonging the healing process. In this letter, we designed and fabricated an easily removable wound dressing material. To accomplish this, we first generated cross-linkable supramonomers through host–guest noncovalent interaction, followed by radical copolymerization of acrylamide with supramonomer as cross-linker to fabricate supramolecular hydrogels. Benefiting from the dynamic nature of the supramonomer, the supramolecular hydrogel is able to dissolve upon exposure to memantine, an FDA approved drug, making it easily removed from a wound, representing a promising candidate for the new generation of wound dressing

Layer-by-Layer Assembly of Azulene-Based Supra-Amphiphiles: Reversible Encapsulation of Organic Molecules in Water by Charge-Transfer Interaction

Stable multilayer films have been fabricated on the basis of alternating layer-by-layer assembly of an azulene-based supra-amphiphile and a photoreactive polyanion. Moreover, one component of the supra-amphiphile, pyrene, can be removed from the multilayer films, generating functional surface-imprinted multilayer films. Uptake experiments show that the surface-imprinted films are capable of recognizing the hydrophobic template molecule in water. The reloading process increases with increasing of temperature. The loading capacity can be regulated by change of the layer pairs. In addition, the as-prepared multilayers are promising in purification of pyrene-polluted water