Abstract
Despite an absence of conventional porosity, the 1D coordination polymer [Ag4(O2C(CF2)2CF3)4(TMP)3] (1; TMP=tetramethylpyrazine) can absorb small alcohols from the vapour phase, which insert into AgO bonds to yield coordination polymers [Ag4(O2C(CF2)2CF3)4(TMP)3(ROH)2] (1-ROH; R=Me, Et, iPr). The reactions are reversible single-crystal-to-single-crystal transformations. Vapour-solid equilibria have been examined by gas-phase IR spectroscopy (K=5.68(9)×10−5 (MeOH), 9.5(3)×10−6 (EtOH), 6.14(5)×10−5 (iPrOH) at 295 K, 1 bar). Thermal analyses (TGA, DSC) have enabled quantitative comparison of two-step reactions 1-ROH12, in which 2 is the 2D coordination polymer [Ag4(O2C(CF2)2CF3)4(TMP)2] formed by loss of TMP ligands exclusively from singly-bridging sites. Four polymorphic forms of 1 (1-ALT, 1-AHT, 1-BLT and 1-BHT; HT=high temperature, LT=low temperature) have been identified crystallographically. In situ powder X-ray diffraction (PXRD) studies of the 1-ROH12 transformations indicate the role of the HT polymorphs in these reactions. The structural relationship between polymorphs, involving changes in conformation of perfluoroalkyl chains and a change in orientation of entire polymers (A versus B forms), suggests a mechanism for the observed reactions and a pathway for guest transport within the fluorous layers. Consistent with this pathway, optical microscopy and AFM studies on single crystals of 1-MeOH/1-AHT show that cracks parallel to the layers of interdigitated perfluoroalkyl chains develop during the MeOH release/uptake process.
Original language | English |
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Pages (from-to) | 8799-8811 |
Number of pages | 13 |
Journal | Chemistry - A European Journal |
Volume | 21 |
Issue number | 24 |
Early online date | 11 May 2015 |
DOIs | |
Publication status | Published - 28 May 2015 |
Keywords
- coordination polymers
- gas-phase spectroscopy
- in situ diffraction
- microscopy
- polymorphism
- porosity
- solid-state reactions
- thermal analysis
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Data for: "Coordination polymer flexibility leads to polymorphism and enables a crystalline solid-vapour reaction: a multi-technique mechanistic study"
Vitõrica-Yrezábal, I. J. (Contributor), Libri, S. (Creator), Loader, J. R. (Creator), Mínguez Espallargas, G. (Contributor), Hippler, M. (Creator), Fletcher, A. J. (Creator), Thompson, S. P. (Creator), Warren, J. E. (Creator), Musumeci, D. (Creator), Ward, M. D. (Creator) & Brammer, L. (Creator), Cambridge Crystallographic Data Centre, 6 Sept 2023
DOI: 10.5517/cc141zms, https://dx.doi.org/10.5517/cc141znt and 2 more links, https://dx.doi.org/10.5517/cc141zpv, https://dx.doi.org/10.5517/cc141zqw (show fewer)
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