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| Type |
Poster Presentation |
| Area |
Inorganic Chemistry |
| Room No. |
Event Hall |
| Time |
4월 19일 (목요일) 11:00~12:30 |
| Code |
INOR.P-217 |
| Subject |
Chirality Inversion in Supramolecular Polymers |
| Authors |
Ka Young Kim, Jong Hwa Jung*
Department of Chemistry, Gyeongsang National University, Korea
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| Abstract |
We report a distinctly different dynamic helix inversion pathway of self-assembled terpyridine-based ligands composed of different numbers of peptide moieties with Co2+ and its amplification of strain-induced chirality from an achiral terpyridine moiety. The helical chirality of the metal centers, coordinated by terpyridine ligands, is controlled by strain induced chirality with complex ligand to Co2+ ratios. We also show that the distinct helical inversion mechanism is significantly dependent on the number of peptides attached to ligands. The helical inversion pathway of the self-assembled ligand (R-1 and S-1) complexes composed of one alanine analogue (R- or S-2-amino-1-propyl moiety) and one long saturated alkyl chain relies on two steps of chirality with different complex geometries, first from strain-induced chirality originating from an octahedral structure to octahedral structure with different helical direction and then on to helical chirality in a square pyramidal structure. In contrast, the helix inversion of the self-assembled R-2 and S-2 complexes containing an alanine analogue and two glycine moieties with Co2+ was followed by one step to form two distinct coexisting complex geometries having the same helical direction. In particular, the Circular Dichroism (CD) intensities of the self-assembled R-1 and R-2 complexes with Co2+ were 900–1500-fold amplified compared to those of free R-1 and R-2. The Gibbs free energy of the self-assembled complexes with different geometries were also calculated by temperature-dependent CD observation; the square pyramidal structure of the self-assembled R-1 complex with Co2+ was more stable than the self-assembled R-2 complex with Co2+. |
| E-mail |
rk5321@gnu.ac.kr |
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121st General Meeting of the KCS