Unique pore selectivity for Cs+ and exceptionally high NH4+ exchange capacity of the chalcogenide material K6Sn[Zn4Sn4S17]
Φόρτωση...
Ημερομηνία
Συγγραφείς
Manos, M. J.
Chrissafis, K.
Kanatzidis, M. G.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
American Chemical Society
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
J Am Chem Soc
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
Highly selective ion-exchange properties and -exchange capacities of the open framework chalcogenide material K6Sn[Zn4Sn4S17] (1) with Cs+ and NH4+ are reported. Because the structure of this framework is known in great detail, these studies are a rare example where structure/property relationships can be directly drawn. 1 possesses three types of micropore cavities. The largest pore of 1 presents an exact fit for Cs+ and exhibits high selectivity for this ion, as demonstrated by competitive ion-exchange experiments. The next largest pore has a greater capacity (up to four cations) and is well suited for NH4+ ions. This leads to a high ammonium-exchange capacity for 1 of 3.06 mequiv/gr, which is close to the NH4+-exchange capacities of natural zeolites. The single-crystal structures of ammonium-exchanged products at various stages reveal an unusual mechanism for the exchange process of 1 which involves diffusion of ammonium cations from the large cavity to the small ones of the framework. Thermal analysis of one of these ammonium-exchanged products, in combination with mass spectroscopy, showed the decomposition of NH4+ cations to NH3 and H2S with the parallel transformation of the exchanged product to a mixture of crystalline phases. Since K6Sn[Zn4Sn4S17] can be grown in suitably large crystals ( much larger than most zeolites), it defines an excellent model system in which ion-exchange processes and products can be characterized and studied in detail in various reaction stages.
Περιγραφή
Λέξεις-κλειδιά
extra-large-pore, ion-exchange, structural-characterization, framework sulfide, porous materials, zeolites, transformation, geometry, channels, clusters
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000238728000040
http://pubs.acs.org/doi/pdfplus/10.1021/ja061342t
http://pubs.acs.org/doi/pdfplus/10.1021/ja061342t
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας