4231-75-8Relevant articles and documents
Higher Order Constitutional Dynamic Networks: [2×3] and [3×3] Networks Displaying Multiple, Synergistic and Competitive Hierarchical Adaptation
Men, Guangwen,Lehn, Jean-Marie
supporting information, p. 2474 - 2483 (2017/02/23)
The present study investigates the constitutional dynamic networks (CDNs) underlying dynamic covalent libraries (DCLs) that extend beyond the [2×2] case toward higher orders, namely [2×3] and [3×3] CDNs involving respectively six and nine constituents generated from the recombination of five and six components linked through reversible chemical reactions. It explores the behavior of such systems under the action of one or two effectors. More specifically and for the sake of proof of principle, it makes use of DCLs involving dynamic organic ligands and analyzes their single and double adaptive response under the action of one and two metal cation effectors. Thus, interconversions within [2×3] DCLs of six constituents (hydrazone, acylhydrazone, and imine ligands) give access to the generation of [2×3] CDNs of 3D trigonal prismatic type consisting of three [2×2] sub-networks and presenting specific responses to the application of Cu+ and Zn2+ metal cation effectors, in particular double agonistic amplification. More complex [3×3] CDNs based on nine ligand constituents of imine, hydrazone, and acylhydrazone types were also designed and subjected to the application of one or two effectors, e.g., Cu+ and Fe2+ metal cations, revealing novel types of adaptive behavior: (i) agonistic amplification between a single constituent and a full [2×2] sub-network, and (ii) agonistic amplification along a single diagonal connecting three constituents. Of special interest is also the dependence of the response of the system to hierarchical sequence of effector application, whereby initial interaction with Cu+ ions results in the destruction of the network, whereas the sequence Fe2+ followed by Cu+ yields a clean three-constituent DCL. Finally and strikingly, the present results also demonstrate that the increase in complexity of the system by introduction of an additional entity leads to a simpler output through dynamic competition between components.
Adaptation in constitutional dynamic libraries and networks, switching between orthogonal metalloselection and photoselection processes
Vantomme, Ghislaine,Jiang, Shimei,Lehn, Jean-Marie
supporting information, p. 9509 - 9518 (2014/07/21)
Constitutional dynamic libraries of hydrazones aAbB and acylhydrazones aAcC undergo reorganization and adaptation in response to a chemical effector (metal cations) or a physical stimulus (light). The set of hydrazones [1A1B, 1A2B, 2A1B, 2A 2B] undergoes metalloselection on addition of zinc cations which drive the amplification of Zn(1A2B)2 by selection of the fittest component 1A2B. The set of acylhydrazones [E-1A1C, 1A2C, 2A1C, 2A2C] undergoes photoselection by irradiation of the system, which causes photoisomerization of E- 1A1C into Z-1A1C with amplification of the latter. The set of acyl hydrazones [E-1A1C, 1A3C, 2A1C, 2A 3C] undergoes a dual adaptation via component exchange and selection in response to two orthogonal external agents: a chemical effector, metal cations, and a physical stimulus, light irradiation. Metalloselection takes place on addition of zinc cations which drive the amplification of Zn( 1A3C)2 by selection of the fittest constituent 1A3C. Photoselection is obtained on irradiation of the acylhydrazones that leads to photoisomerization from E-1A 1C to Z-1A1C configuration with amplification of the latter. These changes may be represented by square constitutional dynamic networks that display up-regulation of the pairs of agonists ( 1A2B, 2A1B), (Z-1A 1C, 2A2C), (1A3C, 2A1C), (Z-1A1C, 2A 3C) and the simultaneous down-regulation of the pairs of antagonists (1A1B, 2A2B), (1A 2C, 2A1C), (E-1A1C, 2A3C), (1A3C, 2A 1C). The orthogonal dual adaptation undergone by the set of acylhydrazones amounts to a network switching process.
