Self-assembling achiral and chiral porphyrin trimers based on benzene tricarboxamide exhibit amplification of chirality only in solvents in which the assemblies are dynamic enough to rearrange their constituting components.
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http://dx.doi.org/10.1039/c2cc31156a | DOI Listing |
Chemistry
January 2025
Indian Institute of Technology Kanpur, Department of Chemistry, Kanpur, 208016, Kanpur, INDIA.
Herein, we report the precise control of molecular to supramolecular chirality induction at the single-molecule level just upon subtle modification in an achiral 'nano-size' trizinc(II) porphyrin trimer. A slight variation in the projection of the substituent at the periphery of the central porphyrin unit in a porphyrin trimer (host) resulted in pronounced changes in the interchromophoric arrangement, leading to distinct 'open' and 'closed' conformations. While 'open' form generates 'monomeric' complex with low CD amplitude, 'closed' form produces exclusive 'polymer' with large, amplified CD signal with opposite sign due to stronger intermolecular excitonic coupling.
View Article and Find Full Text PDFOrg Lett
December 2024
School of Chemistry and Chemical Engineering/State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, Shihezi University, Shihezi, Xinjiang 832003, China.
Easily obtainable and efficient chiral -symmetric bipyridine-,'-dioxide ligands with Ni(OTf) were developed for application in catalyzing [3 + 2] cycloaddition reactions to synthesize optically active fused pyrazolidines or pyrazoline derivatives featuring three contiguous stereogenic centers by employing azomethine imines and α,β-unsaturated 2-acyl imidazoles, affording the corresponding adducts with the opposite configuration compared to previous synthetic products in 80-98% yields with 28-99% ee and >20:1 dr. In addition, subsequent amplification experiments and derivative transformations of the product further demonstrated the efficient catalytic performance of the catalyst Ni(II)-bipyridine-,'-dioxide complexes and the practicality of this synthesis methodology.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Shanghai Jiaotong University: Shanghai Jiao Tong University, School of Chemistry and Chemical Engineeringg, Dongchuan Road, Num 800, 200092, Shanghai, CHINA.
Circularly polarized luminescence (CPL) film attracted considerable attention in information storage and encryption, three-dimensional display, and chiral recognition. However, due to the limited molecular mobility within thin film, achieving a high asymmetry factor and non-contact modulation of CPL remain challenging. In this work, color-switchable homochiral CPL films with high luminescence asymmetry factor (glum~0.
View Article and Find Full Text PDFSmall
December 2024
State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
Currently, circularly polarized luminescence (CPL) has drawn wide interest in 3D display, information storage, and optical sensing. However, traditional synthetic paths are often accompanied by low chiral optical intensity and complex processes. Cellulose nanocrystals (CNCs), with the properties of liquid crystals, can spontaneously arrange into the left-handed layered nanofilm, which enables them candidates in the construction of CPL materials.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Beijing Institute of Smart Energy, Beijing 102200, China.
Supramolecular chirality has gained immense attention for great potential, in which the rational engineering strategy facilitates unique helical stacking/assembly, high chiroptical behavior, and prime biomedical activity. In this study, we reported a novel chiral organic donor-acceptor cocrystal based on asymmetrical components of benzo()naphtho(1,2-)thiophene (BNT) and 9-oxo-9H-indeno(1,2-)pyrazine-2,3-dicarbonitrile (DCAF) that exhibited red emission using a simple solution approach. During the self-assembly, a kinetically controlled growth of polar solvent or substrate induction led to the chiral packing and helical morphology twisted by the cooperation of electrostatic potential energy and chirality.
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