Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Anionic silicate organic frameworks constructed from hexacoordinate silicon centres
AU - Roeser, Jerome
AU - Prill, Dragica
AU - Bojdys, Michael J.
AU - Fayon, Pierre
AU - Trewin, Abbie
AU - Fitch, Andrew N.
AU - Schmidt, Martin U.
AU - Thomas, Arne
PY - 2017/10/1
Y1 - 2017/10/1
N2 - Crystalline frameworks composed of hexacoordinate silicon species have thus far only been observed in a few high pressure silicate phases. By implementing reversible Si-O chemistry for the crystallization of covalent organic frameworks, we demonstrate the simple one-pot synthesis of silicate organic frameworks based on octahedral dianionic SiO6 building units. Clear evidence of the hexacoordinate environment around the silicon atoms is given by Si-29 nuclear magnetic resonance analysis. Characterization by high-resolution powder X-ray diffraction, density functional theory calculation and analysis of the pair-distribution function showed that those anionic frameworks-M-2[Si(C16H10O4)(1.5)], where M = Li, Na, K and C16H10O4 is 9,10-dimethylanthracene-2,3,6,7-tetraolate-crystallize as two-dimensional hexagonal layers stabilized in a fully eclipsed stacking arrangement with pronounced disorder in the stacking direction. Permanent microporosity with high surface area (up to 1,276 m(2) g(-1)) was evidenced by gas-sorption measurements. The negatively charged backbone balanced with extra-framework cations and the permanent microporosity are characteristics that are shared with zeolites.
AB - Crystalline frameworks composed of hexacoordinate silicon species have thus far only been observed in a few high pressure silicate phases. By implementing reversible Si-O chemistry for the crystallization of covalent organic frameworks, we demonstrate the simple one-pot synthesis of silicate organic frameworks based on octahedral dianionic SiO6 building units. Clear evidence of the hexacoordinate environment around the silicon atoms is given by Si-29 nuclear magnetic resonance analysis. Characterization by high-resolution powder X-ray diffraction, density functional theory calculation and analysis of the pair-distribution function showed that those anionic frameworks-M-2[Si(C16H10O4)(1.5)], where M = Li, Na, K and C16H10O4 is 9,10-dimethylanthracene-2,3,6,7-tetraolate-crystallize as two-dimensional hexagonal layers stabilized in a fully eclipsed stacking arrangement with pronounced disorder in the stacking direction. Permanent microporosity with high surface area (up to 1,276 m(2) g(-1)) was evidenced by gas-sorption measurements. The negatively charged backbone balanced with extra-framework cations and the permanent microporosity are characteristics that are shared with zeolites.
KW - MOLECULAR SIMULATIONS
KW - CRYSTAL-STRUCTURES
KW - COMPLEXES
KW - 5-COORDINATE
U2 - 10.1038/NCHEM.2771
DO - 10.1038/NCHEM.2771
M3 - Journal article
VL - 9
SP - 977
EP - 982
JO - Nature Chemistry
JF - Nature Chemistry
SN - 1755-4330
IS - 10
ER -