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)

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…

Directional Shuttling of a Stimuli-Responsive Cone-Like Macrocycle on a Single-State Symmetric Dumbbell Axle

Rotaxane-based molecular shuttles are often operated using low-symmetry axles and changing the states of the binding stations. A molecular shuttle capable of directional shuttling of an acid-responsive cone-like macrocycle on a single-state symmetric dumbbell axle is now presented. The axle contains three binding stations: one symmetric di(quaternary ammonium) station and two nonsymmetric phenyl triazole stations arranged in opposite orientations. Upon addition of an acid, the protonated macrocycle shuttles from the di(quaternary ammonium) station to the phenyl triazole binding station closer to its butyl groups. This directional shuttling presumably originates from charge repulsion and an …

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

Achieving Strong Positive Cooperativity through Activating Weak Non‐Covalent Interactions

CCDC 1826426: Experimental Crystal Structure Determination

Related Article: Jie‐Shun Cui, Qian‐Kai Ba, Hua Ke, Arto Valkonen, Kari Rissanen, Wei Jiang|2018|Angew.Chem.,Int.Ed.|57|7809|doi:10.1002/anie.201803349

CCDC 1828064: Experimental Crystal Structure Determination

Related Article: Jie‐Shun Cui, Qian‐Kai Ba, Hua Ke, Arto Valkonen, Kari Rissanen, Wei Jiang|2018|Angew.Chem.,Int.Ed.|57|7809|doi:10.1002/anie.201803349

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

CCDC 1826427: Experimental Crystal Structure Determination

Related Article: Jie‐Shun Cui, Qian‐Kai Ba, Hua Ke, Arto Valkonen, Kari Rissanen, Wei Jiang|2018|Angew.Chem.,Int.Ed.|57|7809|doi:10.1002/anie.201803349