Synthesis of STW zeolites using imidazolium-based dications of varying length

Dications consisting of 1,2-dimethylimidazolium units linked by chains of 4, 5 or 6 methylene groups display structure direction towards the chiral zeolite STW as racemic conglomerates with decreasing strength as the length of the linker increases. A phase transformation from the denser and less str...

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Detalhes bibliográficos
Autores: Lu, Peng, Gómez-Hortigüela Sainz, Luis, Xu, Lei, Camblor, Miguel Ángel
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2017
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/164498
Acesso em linha:http://hdl.handle.net/10261/164498
Access Level:acceso abierto
Palavra-chave:Zeolites
Chirality
Synthesis
Theory-Experiment
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spelling Synthesis of STW zeolites using imidazolium-based dications of varying lengthLu, PengGómez-Hortigüela Sainz, LuisXu, LeiCamblor, Miguel ÁngelZeolitesChiralitySynthesisTheory-ExperimentDications consisting of 1,2-dimethylimidazolium units linked by chains of 4, 5 or 6 methylene groups display structure direction towards the chiral zeolite STW as racemic conglomerates with decreasing strength as the length of the linker increases. A phase transformation from the denser and less strained MTW to the less dense and more strained STW reveals significant stabilization in the case of the 4-methylene dication, which is able to produce STW even in the absence of germanium (i.e., for a pure silica composition), and to a lesser extent for the 5-methylene derivative. When Ge is introduced in the synthesis the crystallization is easier and the crystallization field is wider, with Ge preferentially occupying positions at the double four ring units of the STW framework, as revealed by Rietveld refinement from synchrotron data. Quantum mechanics calculations show that the interaction energy diminishes as the length of the linker increases, in agreement with the experimental findings. In addition, calculation of the 13C NMR chemical shieldings and comparison with experimental spectra allowed us to identify different conformations and orientations of the imidazolium rings in the asymmetric STW cavities, depending on the spacer length. An exploratory study strongly suggests that an asymmetric derivative with additional methyl groups at both sides of the tetramethylene chain could afford the crystallization of the homochiral zeolite even as a pure silica material.Ministerio de Economía y Competitividad, proyectos MAT-2015-65767-P y MAT2015-71117-RPeer reviewedRoyal Society of Chemistry (UK)Ministerio de Economía y Competitividad (España)Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]201820182017info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Publisher's versioninfo:eu-repo/semantics/publishedVersionhttp://hdl.handle.net/10261/164498reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Ingléshttp://pubs.rsc.org/en/content/articlehtml/2018/ta/c7ta10002gSíinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/1644982026-05-22T06:33:51Z
dc.title.none.fl_str_mv Synthesis of STW zeolites using imidazolium-based dications of varying length
title Synthesis of STW zeolites using imidazolium-based dications of varying length
spellingShingle Synthesis of STW zeolites using imidazolium-based dications of varying length
Lu, Peng
Zeolites
Chirality
Synthesis
Theory-Experiment
title_short Synthesis of STW zeolites using imidazolium-based dications of varying length
title_full Synthesis of STW zeolites using imidazolium-based dications of varying length
title_fullStr Synthesis of STW zeolites using imidazolium-based dications of varying length
title_full_unstemmed Synthesis of STW zeolites using imidazolium-based dications of varying length
title_sort Synthesis of STW zeolites using imidazolium-based dications of varying length
dc.creator.none.fl_str_mv Lu, Peng
Gómez-Hortigüela Sainz, Luis
Xu, Lei
Camblor, Miguel Ángel
author Lu, Peng
author_facet Lu, Peng
Gómez-Hortigüela Sainz, Luis
Xu, Lei
Camblor, Miguel Ángel
author_role author
author2 Gómez-Hortigüela Sainz, Luis
Xu, Lei
Camblor, Miguel Ángel
author2_role author
author
author
dc.contributor.none.fl_str_mv Ministerio de Economía y Competitividad (España)
Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
dc.subject.none.fl_str_mv Zeolites
Chirality
Synthesis
Theory-Experiment
topic Zeolites
Chirality
Synthesis
Theory-Experiment
description Dications consisting of 1,2-dimethylimidazolium units linked by chains of 4, 5 or 6 methylene groups display structure direction towards the chiral zeolite STW as racemic conglomerates with decreasing strength as the length of the linker increases. A phase transformation from the denser and less strained MTW to the less dense and more strained STW reveals significant stabilization in the case of the 4-methylene dication, which is able to produce STW even in the absence of germanium (i.e., for a pure silica composition), and to a lesser extent for the 5-methylene derivative. When Ge is introduced in the synthesis the crystallization is easier and the crystallization field is wider, with Ge preferentially occupying positions at the double four ring units of the STW framework, as revealed by Rietveld refinement from synchrotron data. Quantum mechanics calculations show that the interaction energy diminishes as the length of the linker increases, in agreement with the experimental findings. In addition, calculation of the 13C NMR chemical shieldings and comparison with experimental spectra allowed us to identify different conformations and orientations of the imidazolium rings in the asymmetric STW cavities, depending on the spacer length. An exploratory study strongly suggests that an asymmetric derivative with additional methyl groups at both sides of the tetramethylene chain could afford the crystallization of the homochiral zeolite even as a pure silica material.
publishDate 2017
dc.date.none.fl_str_mv 2017
2018
2018
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
Publisher's version
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/164498
url http://hdl.handle.net/10261/164498
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv http://pubs.rsc.org/en/content/articlehtml/2018/ta/c7ta10002g
Sí
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Royal Society of Chemistry (UK)
publisher.none.fl_str_mv Royal Society of Chemistry (UK)
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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