Cover Picture: Achieving Strong Positive Cooperativity through Activating Weak Non‐Covalent Interactions (Angew. Chem. Int. Ed. 3/2018)

Titelbild: Achieving Strong Positive Cooperativity through Activating Weak Non‐Covalent Interactions (Angew. Chem. 3/2018)

A supramolecular system that strictly follows the binding mechanism of conformational selection

Induced fit and conformational selection are two dominant binding mechanisms in biology. Although induced fit has been widely accepted by supramolecular chemists, conformational selection is rarely studied with synthetic systems. In the present research, we report a macrocyclic host whose binding mechanism is unambiguously assigned to conformational selection. The kinetic and thermodynamic aspects of this system are studied in great detail. It reveals that the kinetic equation commonly used for conformational selection is strictly followed here. In addition, two mathematical models are developed to determine the association constants of the same guest to the two host conformations. A “confo…

Achieving Strong Positive Cooperativity through Activating Weak Non-Covalent Interactions

Positive cooperativity achieved through activating weak non-covalent interactions is common in biological assemblies but is rarely observed in synthetic complexes. Two new molecular tubes have been synthesized and the syn isomer binds DABCO-based organic cations with high orientational selectivity. Surprisingly, the ternary complex with two hosts and one guest shows a high cooperativity factor (α=580), which is the highest reported for synthetic systems without involving ion-pairing interactions. The X-ray single-crystal structure revealed that the strong positive cooperativity likely originates from eight C-H⋅⋅⋅O hydrogen bonds between the two head-to-head-arranged syn tube molecules. Thes…

CCDC 1577841: Experimental Crystal Structure Determination

Related Article: Yan-Long Ma, Hua Ke, Arto Valkonen, Kari Rissanen, Wei Jiang|2018|Angew.Chem.,Int.Ed.|57|709|doi:10.1002/anie.201711077

CCDC 1575263: Experimental Crystal Structure Determination

Related Article: Yan-Long Ma, Hua Ke, Arto Valkonen, Kari Rissanen, Wei Jiang|2018|Angew.Chem.,Int.Ed.|57|709|doi:10.1002/anie.201711077

CCDC 1575262: Experimental Crystal Structure Determination

Related Article: Yan-Long Ma, Hua Ke, Arto Valkonen, Kari Rissanen, Wei Jiang|2018|Angew.Chem.,Int.Ed.|57|709|doi:10.1002/anie.201711077

CCDC 1950443: Experimental Crystal Structure Determination

Related Article: Liu-Pan Yang, Li Zhang, Mao Quan, Jas S. Ward, Yan-Long Ma, Hang Zhou, Kari Rissanen, Wei Jiang|2020|Nat.Commun.|11|2740|doi:10.1038/s41467-020-16534-9

CCDC 1577842: Experimental Crystal Structure Determination

Related Article: Yan-Long Ma, Hua Ke, Arto Valkonen, Kari Rissanen, Wei Jiang|2018|Angew.Chem.,Int.Ed.|57|709|doi:10.1002/anie.201711077