Halogenated Sodium-closo-Dodecaboranes as Solid-State Ion Conductors
Sodium compounds containing large weakly coordinating anions are explored as ion conductors. The halogenated sodium-closo-dodecaboranes (Na2B12Cl12, Na2B12Br12, and Na2B12I12) are all isostructural (Pa3¯) at room temperature. These compounds undergo an order-disorder polymorphic transition to Fm3¯m...
| Main Authors: | , , , |
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| Format: | Journal Article |
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American Chemical Society
2017
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| Online Access: | http://hdl.handle.net/20.500.11937/53361 |
| _version_ | 1848759125490532352 |
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| author | Hansen, B. Paskevicius, Mark Jørgensen, M. Jensen, T. |
| author_facet | Hansen, B. Paskevicius, Mark Jørgensen, M. Jensen, T. |
| author_sort | Hansen, B. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Sodium compounds containing large weakly coordinating anions are explored as ion conductors. The halogenated sodium-closo-dodecaboranes (Na2B12Cl12, Na2B12Br12, and Na2B12I12) are all isostructural (Pa3¯) at room temperature. These compounds undergo an order-disorder polymorphic transition to Fm3¯m where Na+ partially occupies two crystallographic sites and [B12X12]2- anions undergo reorientational motion. These dynamic structural properties promote extreme Na+ ion conductivity up to 0.162 S/cm at elevated temperature (500 °C). The polymorphic transition temperatures increase down the halogen group (Cl < Br < I). These temperatures are much higher (475, 525, and 570 °C) than for Na2B12H12 (266 °C), which could be related to increasing anion size, mass, and the anisotropic electron density in the covalently bound halogens (B-X). The halogens may form Na-X interactions with increasing strength and directionality, which restrict dynamic motion until high temperature. The halogenated sodium-closo-dodecaboranes demonstrate excellent thermal stabilities (up to 500 °C) and may facilitate the development of new high temperature ion conductors. |
| first_indexed | 2025-11-14T09:54:55Z |
| format | Journal Article |
| id | curtin-20.500.11937-53361 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:54:55Z |
| publishDate | 2017 |
| publisher | American Chemical Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-533612017-10-20T01:49:20Z Halogenated Sodium-closo-Dodecaboranes as Solid-State Ion Conductors Hansen, B. Paskevicius, Mark Jørgensen, M. Jensen, T. Sodium compounds containing large weakly coordinating anions are explored as ion conductors. The halogenated sodium-closo-dodecaboranes (Na2B12Cl12, Na2B12Br12, and Na2B12I12) are all isostructural (Pa3¯) at room temperature. These compounds undergo an order-disorder polymorphic transition to Fm3¯m where Na+ partially occupies two crystallographic sites and [B12X12]2- anions undergo reorientational motion. These dynamic structural properties promote extreme Na+ ion conductivity up to 0.162 S/cm at elevated temperature (500 °C). The polymorphic transition temperatures increase down the halogen group (Cl < Br < I). These temperatures are much higher (475, 525, and 570 °C) than for Na2B12H12 (266 °C), which could be related to increasing anion size, mass, and the anisotropic electron density in the covalently bound halogens (B-X). The halogens may form Na-X interactions with increasing strength and directionality, which restrict dynamic motion until high temperature. The halogenated sodium-closo-dodecaboranes demonstrate excellent thermal stabilities (up to 500 °C) and may facilitate the development of new high temperature ion conductors. 2017 Journal Article http://hdl.handle.net/20.500.11937/53361 10.1021/acs.chemmater.6b04797 American Chemical Society restricted |
| spellingShingle | Hansen, B. Paskevicius, Mark Jørgensen, M. Jensen, T. Halogenated Sodium-closo-Dodecaboranes as Solid-State Ion Conductors |
| title | Halogenated Sodium-closo-Dodecaboranes as Solid-State Ion Conductors |
| title_full | Halogenated Sodium-closo-Dodecaboranes as Solid-State Ion Conductors |
| title_fullStr | Halogenated Sodium-closo-Dodecaboranes as Solid-State Ion Conductors |
| title_full_unstemmed | Halogenated Sodium-closo-Dodecaboranes as Solid-State Ion Conductors |
| title_short | Halogenated Sodium-closo-Dodecaboranes as Solid-State Ion Conductors |
| title_sort | halogenated sodium-closo-dodecaboranes as solid-state ion conductors |
| url | http://hdl.handle.net/20.500.11937/53361 |