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Publication
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| Research Title |
Guest-Induced Phase Transformation with Chromotropism in Cobalt(II) Supramolecular Frameworks |
| Date of Distribution |
4 November 2013 |
| Conference |
| Title of the Conference |
4th Asian Conference on Coordination Chemistry (4ACCC) |
| Organiser |
Jeju, South Korea |
| Conference Place |
International Convention Center Jeju (ICCJEJU), Jeju, South Korea |
| Province/State |
Jeju, South Korea |
| Conference Date |
4 November 2013 |
| To |
7 November 2013 |
| Proceeding Paper |
| Volume |
1 |
| Issue |
1 |
| Page |
120 |
| Editors/edition/publisher |
Seoul National University |
| Abstract |
Three new supramolecular frameworks [Co(pydc)(H2O)2]n (1), [Co(pydc)(H2O)4]n(H2O)n (2) and [Co(Hampy)2(H2O)4](SO4)2(H2O)3 (3) (pydc = 3,5-pyridinedicarboxylate and ampy = 4-aminomethylpyridine) have been synthesized. The structure of 1 reveals an infinite 2D layer with honeycomb-like cavities in which each pydc ligand bridges three Co(II) ions. The adjacent 2D layers are orderly packed in an ABAB-type array via intermolecular interactions of the combined π–π stacking and hydrogen bonds to form a 3D supramolecular architecture. In case of compound 2, pydc acts as didentate bridging ligand connecting two Co(II) ions, leading to a 1D zig-zag chain. Guest water molecules fill the gaps in between chains and form hydrogen bonds with the host chains stabilizing the 3D network of 2. For compound 3, the structure contains a mononuclear [Co(Hampy)2(H2O)4]4+ cation unit, two sulfate ions, and three lattice water molecules. Each mononuclear cation unit is assembled by intermolecular hydrogen bonding and π–π stacking interactions by the coordinated and lattice water molecules, amino group, and sulfate anions to form a 3D supramolecular network. Interestingly, compounds 1-3 exhibit a guest induced crystal-to-amorphous transformation with chromotropism. For compound 1, when an amorphous phase (1A) was exposed to water vapor, it was readily converted into the second crystalline phase 1B with a color change. Moreover, a reversible process between 1A and 1B was performed. Compounds 2 and 3 also exhibit water induced reversible crystal-to-amorphous transformation with chromotropism. Surprisingly, the IR and UV-vis spectra, elemental analysis, TGA curve and XRPD pattern of the rehydrated second phase 1B are found to be identical to that of 2 and rehydrated 2′, these results confirm that 2, rehydrated 2′ and 1B are the same compound. In addition, compound 3 also shows the dynamic structural behaviour when exposed to methanol vapour. Therefore, the conspicuous response of the dehydrated amorphous form of all three compounds to the presence of water and methanol suggests that these compounds could be employed as an indicator for humidity and methanol vapour. |
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| Peer Review Status |
มีผู้ประเมินอิสระ |
| Level of Conference |
นานาชาติ |
| Type of Proceeding |
Abstract |
| Type of Presentation |
Poster |
| Part of thesis |
true |
| Presentation awarding |
false |
| Attach file |
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| Citation |
0
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Journal Publication
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