Mechanically interlocked molecules (MIMs) have unique properties with broad applications, yet constructing both knotted and linked topologies from the same ligand remains challenging due to their distinct geometric de...Mechanically interlocked molecules (MIMs) have unique properties with broad applications, yet constructing both knotted and linked topologies from the same ligand remains challenging due to their distinct geometric demands. To address this, we design and synthesize a conformationally adaptive ligand 4,7-bis(3-(pyridin-4-yl) phenyl) benzo[c][1,2,5]thiadiazole (L1) with a tunable torsional angle θ of N1C1C2N2 ranging from 7.5° to 108.9°. Utilizing coordination-driven self-assembly at ambient temperature, L1 selectively assembles with binuclear half-sandwich units RhB1, RhB2, RhB3, and RhB4 featuring Cp*^(Rh^(Ⅲ)) (Cp* = η^(5)-pentam-ethylcyclopentadienyl) into distinct topologies: Solomon links Rh-1, trefoil knots Rh-2, molecular tweezers Rh 3, and Rh-4, respectively. Crucially, the self-adaptability of ligand L1 directs topology formation through pro-gramming different combination of noncovalent interactions (π-x stacking, CH..π interaction, and lone pair-π interaction), thus navigating divergent assembly pathways by conformational switching, as evidenced by X-ray crystallography analysis, independent gradient model (IGM) analysis, detailed nuclear magnetic resonance (NMR) spectroscopy and electrospray ionization time-of-flight/mass spectrometry (ESI-TOF/MS). This strategy can also be extended to construct Cp*^(Irl^(Ⅲ)) analogs (Solomon links Ir-1, trefoil knots Ir-2, molecular tweezers Ir-3 and Ir-4), demonstrating metal-independent control and achieving intricate topologies in a high yield.展开更多
The 6-isoquinolinyl system was incorporated into mechanically interlocked molecules(MIMs)syntheses for comparative analysis of its assembly behavior with 4-pyridyl-based coordination ligands,where a coordination-drive...The 6-isoquinolinyl system was incorporated into mechanically interlocked molecules(MIMs)syntheses for comparative analysis of its assembly behavior with 4-pyridyl-based coordination ligands,where a coordination-driven self-assembly strategy by half-sandwich Cp^(*)Rh units was employed to construct diverse molecular links.The pyridyl ligand,adorned with thiophene moieties,assembles into[2]catenanes(2_(1)^(2)links),whereas the isoquinolinyl ligand produces molecular Borromean links(6_(2)^(3)links).Intriguingly,when utilizing extended bithiophene segments,the pyridyl ligand forms Borromean rings(6_(2)^(3)links),while isoquinolinyl counterparts produced a rare low-symmetry cyclic[3]catenane(6_(3)^(3)topology).The results were confirmed through single-crystal X-ray diffraction analysis,nuclear magnetic resonance(NMR)spectroscopy,and electrospray ionization time-of-flight mass spectrometry(ESI-TOF/MS)experiments.Synergistic π-π stacking,C-H···π interactions,and solvophobic effects governed the complex self-assembly system,with independent gradient model(IGM)analyses and solventaccessible surface area(SASA)calculations providing atomistic insights into the pathway selectivity of distinct topological links.展开更多
基金Department of Chemistry,Fudan Uni-versity,the National Natural Science Foundation of China(22031003,21720102004)the Shanghai Science Technology Committee(19DZ227010O)the Alexander von Humboldt Foundation for a Humboldt Research Award.
文摘Mechanically interlocked molecules (MIMs) have unique properties with broad applications, yet constructing both knotted and linked topologies from the same ligand remains challenging due to their distinct geometric demands. To address this, we design and synthesize a conformationally adaptive ligand 4,7-bis(3-(pyridin-4-yl) phenyl) benzo[c][1,2,5]thiadiazole (L1) with a tunable torsional angle θ of N1C1C2N2 ranging from 7.5° to 108.9°. Utilizing coordination-driven self-assembly at ambient temperature, L1 selectively assembles with binuclear half-sandwich units RhB1, RhB2, RhB3, and RhB4 featuring Cp*^(Rh^(Ⅲ)) (Cp* = η^(5)-pentam-ethylcyclopentadienyl) into distinct topologies: Solomon links Rh-1, trefoil knots Rh-2, molecular tweezers Rh 3, and Rh-4, respectively. Crucially, the self-adaptability of ligand L1 directs topology formation through pro-gramming different combination of noncovalent interactions (π-x stacking, CH..π interaction, and lone pair-π interaction), thus navigating divergent assembly pathways by conformational switching, as evidenced by X-ray crystallography analysis, independent gradient model (IGM) analysis, detailed nuclear magnetic resonance (NMR) spectroscopy and electrospray ionization time-of-flight/mass spectrometry (ESI-TOF/MS). This strategy can also be extended to construct Cp*^(Irl^(Ⅲ)) analogs (Solomon links Ir-1, trefoil knots Ir-2, molecular tweezers Ir-3 and Ir-4), demonstrating metal-independent control and achieving intricate topologies in a high yield.
基金supported by the Department of Chemistry,Fudan Universitythe National Natural Science Foundation of China(22031003,21720102004)the Shanghai Science Technology Committee(19DZ2270100)。
文摘The 6-isoquinolinyl system was incorporated into mechanically interlocked molecules(MIMs)syntheses for comparative analysis of its assembly behavior with 4-pyridyl-based coordination ligands,where a coordination-driven self-assembly strategy by half-sandwich Cp^(*)Rh units was employed to construct diverse molecular links.The pyridyl ligand,adorned with thiophene moieties,assembles into[2]catenanes(2_(1)^(2)links),whereas the isoquinolinyl ligand produces molecular Borromean links(6_(2)^(3)links).Intriguingly,when utilizing extended bithiophene segments,the pyridyl ligand forms Borromean rings(6_(2)^(3)links),while isoquinolinyl counterparts produced a rare low-symmetry cyclic[3]catenane(6_(3)^(3)topology).The results were confirmed through single-crystal X-ray diffraction analysis,nuclear magnetic resonance(NMR)spectroscopy,and electrospray ionization time-of-flight mass spectrometry(ESI-TOF/MS)experiments.Synergistic π-π stacking,C-H···π interactions,and solvophobic effects governed the complex self-assembly system,with independent gradient model(IGM)analyses and solventaccessible surface area(SASA)calculations providing atomistic insights into the pathway selectivity of distinct topological links.
