Ultralow‐Molecular‐Weight Stimuli‐Responsive and Multifunctional Supramolecular Gels Based on Monomers and Trimers of Hydrazides

Abstract

The simpler, the better. A series of simple, neutral and ultralow-molecular-weight (MW: 140-200) hydrazidederived supramolecular gelators have been designed and synthesized in two straightforward steps. For non-conjugated cyclohexane-derived hydrazides, their monomers can selfassemble to form gels through intermolecular hydrogen bonds and dipole-dipole interactions. Significantly, conjugated phthalhydrazide can self-aggregate into planar and circular trimers through intermolecular hydrogen bonds and then self-assemble to form gels through intermolecular π-π stacking interactions. It is interesting that these simple gelators exhibit unusual properties, such as self-healing, multi-response fluorescence, and visual and selective recognition of chiral (R)/(S)-1,1'-binaphthalene-2,2'-diamine and S 2À through much different times of gel reformation and bluegreen color change, respectively. These results underline the importance of supramolecular gels and extend the scope of supramolecular gelators.

Highly Phosphorescent Planar Chirality by Bridging Two Square-Planar Platinum(II) Complexes: Chirality Induction and Circularly Polarized Luminescence

“…At first, we used the 5-phenyl-OXT ligand to prepare binuclear Pt­(II) complexes, but we failed due to the very poor solubility. Then Cy-OXT and BINA-OXT ligands were adopted because of their good solubility. ,, A 1 mL portion of CH 2 Cl 2 could dissolve at least 60, 20, 100 and 90 mg of Race-Cy-A , Race-Cy-B , ( R , R , R )-BINA-A and ( R , R , R )-BINA-B , respectively,. The single crystals of Race-Cy-A (CCDC: 2117798) and ( R , R , R )-BINA-A (CCDC: 2117799) were obtained by a slow diffusion and evaporation of CH 3 CN/CH 2 Cl 2 solutions.…”

Amino Acid-Based Molecular and Membranous Chiral Tools for Enantiomeric Recognition

“…The need for technologies to discriminate between the enantiomers of a chiral compound has been realized not only in the field of biomedical sciences but also in the pharmacology and food industries. − In this regard, the past decades have witnessed an increased effort in developing strategies for cost-effective and convenient approaches to replace tedious and intricate analytical techniques. − Inspired by the enantioselectivity exhibited by the biological systems, chiral supramolecular systems offer a means to distinctly self-assemble with the enantiomers. − The intrinsic nature of the supramolecular interactions allows the translation of molecular-level interactions to the microscopic level, which is further amplified in their macroscopic behavior. These macroscopic variations can be monitored through color change, precipitation, gel formation, or gel collapse. − …”

Gallic‐Acid‐Modified Naphthalimide Containing Disulfide Bond as Reduction‐Responsive Supramolecular Organogelator

“…[8] Both low molecular-weight gelators (LMWGs) [9] and polymeric gelators [10] have been utilized to construct stimuli-responsive gels. LMWGs in solutions self-assemble to form supramolecular architectures through noncovalent interactions [11] such as electrostatic binding, [12] van der Waals force, [13] hydrogen bonding, [14] guest-host pairing, [15] and π-π stacking. [16] In contrast, polymeric gelators form gels by trapping solvents in the nanopores of large polymer networks.…”