- A highly efficient artificial light-harvesting system with two-step sequential energy transfer based on supramolecular self-assembly
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A highly efficient artificial light-harvesting system (ALHS) in the aqueous phase with a two-step sequential energy transfer process has been successfully constructed based on the host-guest interaction between a water-soluble pillar[5]arene (WP5) and a b
- Han, Tingting,Hu, Xiao-Yu,Jiao, Jianmin,Qian, Weirui,Shi, Yukun,Sun, Guangping,Wang, Leyong
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supporting information
p. 9590 - 9596
(2020/06/05)
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- Shape-Selective Recognition of Quaternary Ammonium Chloride Ion Pairs
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Synthetic receptors that recognize ion pairs are potentially useful for many technical applications, but to date there has been little work on selective recognition of quaternary ammonium (Q+) ion pairs. This study measured the affinity of a tetralactam macrocycle for 11 different Q+·Cl- salts in chloroform solution. In each case, NMR spectroscopy was used to determine the association constant (Ka) and the structure of the associated complex. Ka was found to depend strongly on the molecular shape of Q+ and was enhanced when Q+ could penetrate the macrocycle cavity and engage in attractive noncovalent interactions with the macrocycle's NH residues and aromatic sidewalls. The highest measured Ka of 7.9 × 103 M-1 was obtained when Q+ was a p-CN-substituted benzylic trimethylammonium. This high-affinity Q+·Cl- ion pair was used as a template to enhance the synthetic yield of macrocyclization reactions that produce the tetralactam receptor or structurally related derivatives. In addition, a permanently interlocked rotaxane was prepared by capping the end of a noncovalent complex composed of the tetralactam macrocycle threaded by a reactive benzylic cation. The synthetic method provides access to a new family of rotaxanated ion pairs that can likely act as anion sensors, molecular shuttles, or transport molecules.
- Li, Dong-Hao,Smith, Bradley D.
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p. 2808 - 2816
(2019/03/26)
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- Imine macrocycle with a deep cavity: Guest-selected formation of syn/anti configuration and guest-controlled reconfiguration
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A dynamic covalent bond is one of the ideal linkages for the construction of large and robust organic architectures. In the present article, we show how organic templates can efficiently transform a complex dynamic imine library into a dynamic imine macrocycle. Not only is the constitution well controlled, but also the syn/anti host configuration is efficiently selected and even the orientation of the guest in the asymmetric cavity of the host can be well aligned. This is attributed to the delicate balance and the cooperation of multiple noncovalent interactions between the hosts and the guests. Through sequential additions of three guests in appropriate amounts, controlled structural reconfiguration of dynamic covalent architectures has been achieved for the first time.
- He, Zhenfeng,Ye, Gang,Jiang, Wei
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supporting information
p. 3005 - 3012
(2015/02/05)
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- Odd-even effect and unusual behavior of dodecyl-substituted analogue observed in the crystal structure of alkyltrimethylammonium-[Ni(dmit) 2]- salts
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A series of [Ni(dmit)2]- (dmit: 1,3-dithiole-2- thione-4,5-dithiolato) salts of alkyltrimethylammonium (Cn: n represents the alkyl chain length; n = 3 and 518) have been prepared and analyzed by X-ray structural analysis. All complex salts have been found to be composed of alternate sheets of [Ni(dmit)2]- anions and sheets of cations with a pronounced interdigitation of the alkyl chains. However, molecular arrangement differed between (C3)[Ni(dmit)2] and other (Cn)[Ni(dmit)2] (n = 518). Adjacent cations were aligned along the long axis of [Ni(dmit)2]- anion in C3 complex salt, while in others (C5-C18 complex salts), they were aligned toward the short axis. Such a difference in arrangement arose from correlativity between the lengths of the long axis of cation and anion, namely CLCA. Furthermore, relative orientation between the alkyl chain of cation and [Ni(dmit)2]- anion differed between the odd- and even-numbered cations for C10-C18. Whereas the plane of alkyl chain for odd-numbered cation was normal to the plane of [Ni(dmit)2]- anion, that of even-numbered cation was parallel. It was also found that C12 analog behaved like odd-numbered cations. However, in C12 salt, the end methyl group of the dodecyl group adopted unusual end-gauche conformation.
- Dai, Kotaro,Nomoto, Kuniharu,Ueno, Shinji,Tomono, Kazuaki,Miyamura, Kazuo
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experimental part
p. 312 - 319
(2011/05/13)
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