Synthesis of Germanosilicate Molecular Sieves from Mono- and Di-Quaternary Ammonium OSDAs Constructed from Benzyl Imidazolium Derivatives: Stabilization of Large Micropore Volumes Including New Molecular Sieve CIT-13

Boal, Ben W.; Deem, Michael W.; Xie, Dan; Kang, Jong Hun; Davis, Mark E.; Zones, Stacey I.

doi:10.1021/acs.chemmater.6b00031

Cited by 33 publications

(42 citation statements)

References 32 publications

(57 reference statements)

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“…In addition to STW, numerous other phases were produced without significant variation in synthesis conditions, including LTA, RTH, IWV, CSV, as well as several phases that could not be identified or consisted of layered organosilicate materials. Synthesis of these microporous materials is not unexpected, because they have all been shown to be derived from similarly shaped imidazole-based OSDAs under crystallization conditions similar to those reported here (25)(26)(27)(28)32).…”

Section: Resultssupporting

confidence: 57%

Enantiomerically enriched, polycrystalline molecular sieves

Brand

Schmidt

Deem

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

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114

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Zeolite and zeolite-like molecular sieves are being used in a large number of applications such as adsorption and catalysis. Achievement of the long-standing goal of creating a chiral, polycrystalline molecular sieve with bulk enantioenrichment would enable these materials to perform enantioselective functions. Here, we report the synthesis of enantiomerically enriched samples of a molecular sieve. Enantiopure organic structure directing agents are designed with the assistance of computational methods and used to synthesize enantioenriched, polycrystalline molecular sieve samples of either enantiomer. Computational results correctly predicted which enantiomer is obtained, and enantiomeric enrichment is proven by high-resolution transmission electron microscopy. The enantioenriched and racemic samples of the molecular sieves are tested as adsorbents and heterogeneous catalysts. The enantioenriched molecular sieves show enantioselectivity for the ring opening reaction of epoxides and enantioselective adsorption of 2-butanol (the R enantiomer of the molecular sieve shows opposite and approximately equal enantioselectivity compared with the S enantiomer of the molecular sieve, whereas the racemic sample of the molecular sieve shows no enantioselectivity). chirality | zeolite | asymmetric catalysis | chiral adsorption

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Section: Resultssupporting

confidence: 57%

Enantiomerically enriched, polycrystalline molecular sieves

Brand

Schmidt

Deem

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

114

140

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“…By combining the structure-directing effects of imidazolium cations, fluoride anions and germanium, three new zeolite structures were discovered: IM-16 (UOS) using 1E3MI [134], IM-20 (UWY) with 1B3MI [135] and CIT-13 using mMBz23DMI (and also oMBz23DMI in a more restricted compositional window [137]). As expected, because of the F and Ge roles, the three of them contain D4R units and this is likely the main effect affording their discovery.…”

Section: Uos Uwy and Cit-13: Imidazolium Fluoride And Germaniummentioning

confidence: 99%

Introduction to the Zeolite Structure-Directing Phenomenon by Organic Species: General Aspects

Gómez‐Hortigüela

Camblor

2017

Structure and Bonding

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During the last years, a tremendous progress has been achieved in the application of new zeolite materials in many different sectors through different pioneering innovations in the field of zeolite synthesis. At the very core of the production of these new zeolite materials lies the use of organic species as structuredirecting agents (SDA), which has been recognized as the most important factor to determine the zeolite product rendered after the crystallization process. These organic species organize the inorganic zeolitic units and drives the crystallization pathway towards the production of particular zeolite framework types. This structure-direction phenomenon frequently works in combination with several other factors related to the chemical composition of the synthesis gels, mainly use of fluoride, concentration (H 2 O/T ratio) and presence of different heteroatoms, which are also relevant for the crystallization of particular zeolite materials. Several properties determine the structure-directing effect of these organic species, especially their molecular size and shape, hydrophobicity, rigidity vs flexibility, and hydrothermal stability. The properties of the zeolitic materials synthesized can be tuned up to a certain point through the use of rationally-selected organic species with particular physico-chemical features as SDA. In this introductory chapter, we briefly review the history of the use of organic cations as SDAs, and give the fundaments of the different aspects related to this structure-direction phenomenon and factors affecting it, explaining the main properties of SDAs, providing some examples of recent uses and trends of organic SDAs, as well as the host-guest chemistry involved. In addition, we pay particular attention to the use of imidazoliumbased organic cations as SDAs because of their current relevance in the synthesis of new zeolite materials.

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“…The NUD-2 zeolite is agermanosilicate with am olar ratio of Ge/Si as low as 0.1:1, from which the highly stable aluminosilicate and siliceous zeolite NUD-2 can be obtained by postsynthetic modification.I ti sn oted that Boal et al reported the synthesis of CIT-13 by using as imilar synthetic system during the preparation of this report. [23] The preliminaryr eport by Boal et al showedt hat CIT-13 is isostructural to NUD-2. Herein, we report our detailed studies on the single-crystal structure and properties of NUD-2.…”

Section: Introductionmentioning

confidence: 99%

A Stable Extra‐Large‐Pore Zeolite with Intersecting 14‐ and 10‐Membered‐Ring Channels

Gao

Chen

et al. 2016

Chemistry A European J

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The development of inorganic frameworks with extra-large pores (larger than 12-membered rings) has attracted considerable attention because of their potential applications in catalysis, the separation of large molecules, and so forth. We herein report the synthesis of the new extra-large-pore zeolite NUD-2 by using the supramolecular self-assembly of simple aromatic organic cations as structure-directing agents (SDAs). NUD-2 is a high-silicon-content germanosilicate with interconnecting 14×10-membered-ring channels. The SDAs in NUD-2 can be removed by calcination in air at 550 °C to yield permanent pores with a BET surface area of 500 m(2) g(-1) . Both germanium and organic cations in NUD-2 can also be removed by treatment with acid at lower temperature, thus not only affording recycling of germanium and SDAs, but also providing a highly stable siliceous zeolite. In addition, aluminum ions can be incorporated into the framework of NUD-2. The NUD-2 structure is yet another extra-large-pore zeolite synthesized by using the supramolecular self-assembling templating approach, thus demonstrating that this approach is a general and applicable strategy for synthesis of new large- and extra-large-pore zeolites.

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Synthesis of Germanosilicate Molecular Sieves from Mono- and Di-Quaternary Ammonium OSDAs Constructed from Benzyl Imidazolium Derivatives: Stabilization of Large Micropore Volumes Including New Molecular Sieve CIT-13

Cited by 33 publications

References 32 publications

Enantiomerically enriched, polycrystalline molecular sieves

Enantiomerically enriched, polycrystalline molecular sieves

Introduction to the Zeolite Structure-Directing Phenomenon by Organic Species: General Aspects

A Stable Extra‐Large‐Pore Zeolite with Intersecting 14‐ and 10‐Membered‐Ring Channels

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