Metallosupramolecules of Macrocycles and Beyond: Networking, Capsules, PSMs, Photochemistry, Chiral Inversion, and Adaptive Recognitions

조회수 : 477 등록일 : 2018.10.10 09:10

일시 : 2018.10.10 17:00
소속 : 경상대학교 화학과
발표자 : 이심성
장소 : AS510
Nature has been a source of scientific inspiration because the relations between structure and function are associated with their behaviors in molecular level. Inspired by the nature’s elaborated fashion, we report several synthetic receptors which recognize specific organic guests via the metal-driven adaptation (Figs. 1-6).1-7
The regioisomers of bis-dithiamacrocycle o-bis-L and m-bis-L react with CuI to yield 1-D polymers, in which each isomer is linked by cubane [Cu4I4] cluster and square [Cu2I2] cluster, respectively (Fig. 1).1,2 The results illustrate the possibility for the adaptive formations of the clusters through the binding site design or alternation.
Post-synthetic modifications (PSMs) provide a powerful tool, not only for creating of new materials, but also for understanding mechanistic pathways. We report an anion exchange process accompanying cation reduction and dimerization via the SCSC transformation.3
The combination of the dicopper platform and 1,4-bis(4-pyridyl)piperazine, afforded the first example of a 1-D polyrotaxane whose “string” and “bead” are constructed from the same components (Fig. 3).4 The bead of stoichiometry has a large rectangular cavity and is threaded onto a stair-like string of composition. The formation of the polyrotaxane is driven by π−π stacking between the string and the beads with precise electronic and steric complementarity between these components. A pathway for the formation of the polyrotaxane is proposed.
In the solid state, photo-induced [2+2] cycloaddition of olefin complexes has been used to generate cyclobutane derivatives as a green technology. Our advances in the preparation of organic polymers via the photo-reaction employing MOFs are introduced (Fig. 4).5
In biological molecular recognition, induced fit via adaptive changes of the receptor is more acceptable than lock-&-key principle. We report a metal-driven cascade complex of macrocycle whose organic guest recognition is anion dependent (Fig. 5).6 In solution, its dimercury(II) perchlorato complex recognizes dabco, but its iodo complex shows no reactivity. In crystals, the dabco recognition is associated with a swing door manner of the anions.
Chiral inversion has been a challenging task because chirality information controls structures and functions of various molecules, artificial nanostructures, DNA, and proteins. We present pillar[5]thiacrown whose planar chiral inversion is driven by a metal ion under the control of anions for the first time (Fig. 6).7 This work demonstrates the first chiral inversion induced by combination of metal ion and anion and presents a new perspective on the coordination chemistry of pillar[n]arenes.
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