Rotaxanes can display molecular chirality solely due to the mechanical bond between the axle and encircling macrocycle without the presence of covalent stereogenic units. However, the synthesis of such molecules remains challenging. We have discovered a combination of reaction partners that function as a chiral interlocking auxiliary to both orientate a macrocycle and, effectively, load it onto a new axle. Here we use these substrates to demonstrate the potential of a chiral interlocking auxiliary strategy for the synthesis of mechanically planar chiral rotaxanes by producing a range of examples with high enantiopurity (93-99% e.e.), including so-called 'impossible' rotaxanes whose axles lack any functional groups that would allow their direct synthesis by other means. Intriguingly, by varying the order of bond-forming steps, we can effectively choose which end of an axle the macrocycle is loaded onto, enabling the synthesis of both hands of a single target using the same reactions and building blocks.
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http://dx.doi.org/10.1038/s41557-021-00825-9 | DOI Listing |
Angew Chem Int Ed Engl
November 2024
Shanghai Key Laboratory of Green Chemistry and Chemical Processes, State Key Laboratory of Petroleum Molecular and Process Engineering, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China.
Starting from AIEgen-functionalized chiral [2]rotaxane building block, we have successfully synthesized a new class of chiral rotaxane-branched dendrimers through controllable divergent strategy for the first time, based on which novel chiral artificial light-harvesting systems (LHSs) were successfully constructed in aqueous phase by sequentially introducing achiral donor and acceptor. More importantly, accompanied by the two-step Förster resonance energy transfer (FRET) process in the resultant artificial LHSs, the sequentially amplified circularly polarized luminescence (CPL) performances were achieved, highlighting that the chiral rotaxane-branched dendrimers could serve as excellent relay for both energy transfer and chirality transmission. Impressively, compared with the sole chiral rotaxane-branched dendrimers, the dissymmetry factors (g) values of the resultant artificial LHSs were amplified by one order of magnitude up to 0.
View Article and Find Full Text PDFChem Sci
October 2024
Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University Shenzhen 518060 P. R. China
Nano Lett
September 2024
School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
This work presents a new strategy to achieve the growth of copper sulfide nanoclusters with high nuclearity. Through a phosphine-assisted C-S reductive cleavage approach, an intrinsically chiral [Cu] cluster passes through a [S-Cu] cluster and transforms into a higher-nuclearity [S-Cu] cluster, which features a core-shell structure with a [Cu] core encapsulated by a chiral [CuS] shell. Interestingly, the spiral arrangement of the bidental ligands on the surface of the [S-Cu] cluster leads to the /-enantiomeric configurations.
View Article and Find Full Text PDFChem Soc Rev
October 2024
Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
The active template synthesis of mechanically interlocked molecular architectures exploits the dual ability of various structural elements (metals or, in the case of metal-free active template synthesis, particular arrangements of functional groups) to serve as both a template for the organisation of building blocks and as a catalyst to facilitate the formation of covalent bonds between them. This enables the entwined or threaded intermediate structure to be covalently captured under kinetic control. Unlike classical passive template synthesis, the intercomponent interactions transiently used to promote the assembly typically do not 'live on' in the interlocked product, meaning that active template synthesis can be traceless and used for constructing mechanically interlocked molecules that do not feature strong binding interactions between the components.
View Article and Find Full Text PDFAdv Sci (Weinh)
October 2024
Beijing National Laboratory of Molecular Sciences and CAS Key Laboratory of Colloid, Interface and Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, ZhongGuanCun North First Street 2, Beijing, 100190, China.
Interactions between lone pairs and aromatic π systems are significant across biology and self-assembled materials. Herein, employing an achiral confinement metal-organic framework (MOF) encapsulates guest molecules, it is successfully realized that lone pair (lp)-π interaction induces fluorescence "turn-on" and circularly polarized luminescence for the first time. The MOFs synthesized based on naphthalenediimide show nearly non-emissive, which can be light-up by introducing acetone or ester guests containing lone pairs-π interaction.
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