Uniaxial negative thermal expansion and metallophilicity in Cu3[Co(CN)6]
We report the synthesis and structural characterisation of the molecular framework copper(I)hexacyanocobaltate(III), Cu3[Co(CN)6], which we find to be isostructural to H3[Co(CN)6] and the colossalnegative thermal expansion material Ag3[Co(CN)6]. Using synchrotron X-ray powder diffraction measurements,...
| Hlavní autoři: | , , , , , , , |
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| Médium: | Journal article |
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Elsevier
2017
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| _version_ | 1826293432087216128 |
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| author | Sapnik, A Liu, X Boström, H Coates, C Overy, A Reynolds, E Tkatchenko, A Goodwin, A |
| author_facet | Sapnik, A Liu, X Boström, H Coates, C Overy, A Reynolds, E Tkatchenko, A Goodwin, A |
| author_sort | Sapnik, A |
| collection | OXFORD |
| description | We report the synthesis and structural characterisation of the molecular framework copper(I)hexacyanocobaltate(III), Cu3[Co(CN)6], which we find to be isostructural to H3[Co(CN)6] and the colossalnegative thermal expansion material Ag3[Co(CN)6]. Using synchrotron X-ray powder diffraction measurements,we find strong positive and negative thermal expansion behaviour respectively perpendicular and parallel to thetrigonal crystal axis:α= 25.4(5) MKa−1andα= − 43.5(8) MKc−1. These opposing effects collectively result in avolume expansivityα= 7.4(11) MKV−1that is remarkably small for an anisotropic molecular framework. Thisthermal response is discussed in the context of the behaviour of the analogous H- and Ag-containing systems.We make use of density-functional theory with many-body dispersion interactions (DFT + MBD) todemonstrate that Cu+…Cu+metallophilic (‘cuprophilic’) interactions are significantly weaker in Cu3[Co(CN)6]than Ag+…Ag+interactions in Ag3[Co(CN)6], but that this lowering of energy scale counterintuitively translatesto a more moderate—rather than enhanced—degree of structural flexibility. The same conclusion is drawn fromconsideration of a simple GULP model, which we also present here. Our results demonstrate that stronginteractions can actually be exploited in the design of ultra-responsive materials if those interactions are set upto act in tension. |
| first_indexed | 2024-03-07T03:30:00Z |
| format | Journal article |
| id | oxford-uuid:ba62fa0f-6cce-4118-b63e-11e8838c7fa3 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T03:30:00Z |
| publishDate | 2017 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | oxford-uuid:ba62fa0f-6cce-4118-b63e-11e8838c7fa32022-03-27T05:09:27ZUniaxial negative thermal expansion and metallophilicity in Cu3[Co(CN)6]Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:ba62fa0f-6cce-4118-b63e-11e8838c7fa3Symplectic Elements at OxfordElsevier2017Sapnik, ALiu, XBoström, HCoates, COvery, AReynolds, ETkatchenko, AGoodwin, AWe report the synthesis and structural characterisation of the molecular framework copper(I)hexacyanocobaltate(III), Cu3[Co(CN)6], which we find to be isostructural to H3[Co(CN)6] and the colossalnegative thermal expansion material Ag3[Co(CN)6]. Using synchrotron X-ray powder diffraction measurements,we find strong positive and negative thermal expansion behaviour respectively perpendicular and parallel to thetrigonal crystal axis:α= 25.4(5) MKa−1andα= − 43.5(8) MKc−1. These opposing effects collectively result in avolume expansivityα= 7.4(11) MKV−1that is remarkably small for an anisotropic molecular framework. Thisthermal response is discussed in the context of the behaviour of the analogous H- and Ag-containing systems.We make use of density-functional theory with many-body dispersion interactions (DFT + MBD) todemonstrate that Cu+…Cu+metallophilic (‘cuprophilic’) interactions are significantly weaker in Cu3[Co(CN)6]than Ag+…Ag+interactions in Ag3[Co(CN)6], but that this lowering of energy scale counterintuitively translatesto a more moderate—rather than enhanced—degree of structural flexibility. The same conclusion is drawn fromconsideration of a simple GULP model, which we also present here. Our results demonstrate that stronginteractions can actually be exploited in the design of ultra-responsive materials if those interactions are set upto act in tension. |
| spellingShingle | Sapnik, A Liu, X Boström, H Coates, C Overy, A Reynolds, E Tkatchenko, A Goodwin, A Uniaxial negative thermal expansion and metallophilicity in Cu3[Co(CN)6] |
| title | Uniaxial negative thermal expansion and metallophilicity in Cu3[Co(CN)6] |
| title_full | Uniaxial negative thermal expansion and metallophilicity in Cu3[Co(CN)6] |
| title_fullStr | Uniaxial negative thermal expansion and metallophilicity in Cu3[Co(CN)6] |
| title_full_unstemmed | Uniaxial negative thermal expansion and metallophilicity in Cu3[Co(CN)6] |
| title_short | Uniaxial negative thermal expansion and metallophilicity in Cu3[Co(CN)6] |
| title_sort | uniaxial negative thermal expansion and metallophilicity in cu3 co cn 6 |
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