Threshold photoionization and density functional theory studies of the niobium carbide clusters Nb3Cn (n=1-4) and Nb4Cn (n=1-6)
We have used photoionization efficiency spectroscopy to determine ionization potentials (IP) of the niobium-carbide clusters, Nb3Cn (n = 1−4) and Nb4Cn (n = 1−6). The Nb3C2 and Nb4C4 clusters exhibit the lowest IPs for the two series, respectively. For clusters containing up to four carbon atoms, ex...
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| Format: | Journal Article |
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American Chemical Society
2008
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| Online Access: | http://hdl.handle.net/20.500.11937/5894 |
| _version_ | 1848744923296169984 |
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| author | Dryza, V. Addicoat, M. Gascooke, J. Buntine, Mark Metha, G. |
| author_facet | Dryza, V. Addicoat, M. Gascooke, J. Buntine, Mark Metha, G. |
| author_sort | Dryza, V. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We have used photoionization efficiency spectroscopy to determine ionization potentials (IP) of the niobium-carbide clusters, Nb3Cn (n = 1−4) and Nb4Cn (n = 1−6). The Nb3C2 and Nb4C4 clusters exhibit the lowest IPs for the two series, respectively. For clusters containing up to four carbon atoms, excellent agreement is found with relative IPs calculated using density functional theory. The lowest energy isomers are mostly consistent with the development of a 2 × 2 × 2 face-centered cubic structure of Nb4C4. However, for Nb3C4 a low-lying isomer containing a molecular C2 unit is assigned to the experimental IP rather than the depleted 2 × 2 × 2 nanocrystal isomer. For Nb4C5 and Nb4C6, interpretation is less straightforward, but results indicate isomers containing molecular C2 units are the lowest in energy, suggesting that carbon−carbon bonding is preferred when the number of carbon atoms exceeds the number of metal atoms. A double IP onset is observed for Nb4C3, which is attributed to ionization from the both the lowest energy singlet state and a meta-stable triplet state. This work further supports the notion that IPs can be used as a reliable validation for the geometries of metal–carbide clusters calculated by theory. |
| first_indexed | 2025-11-14T06:09:10Z |
| format | Journal Article |
| id | curtin-20.500.11937-5894 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:09:10Z |
| publishDate | 2008 |
| publisher | American Chemical Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-58942017-09-13T14:38:34Z Threshold photoionization and density functional theory studies of the niobium carbide clusters Nb3Cn (n=1-4) and Nb4Cn (n=1-6) Dryza, V. Addicoat, M. Gascooke, J. Buntine, Mark Metha, G. Ionization-potentials Carbon clusters Electronic states Nanocrystals Reactivity Molecules Spectroscopy Transition-metal clusters Spectra Dynamics We have used photoionization efficiency spectroscopy to determine ionization potentials (IP) of the niobium-carbide clusters, Nb3Cn (n = 1−4) and Nb4Cn (n = 1−6). The Nb3C2 and Nb4C4 clusters exhibit the lowest IPs for the two series, respectively. For clusters containing up to four carbon atoms, excellent agreement is found with relative IPs calculated using density functional theory. The lowest energy isomers are mostly consistent with the development of a 2 × 2 × 2 face-centered cubic structure of Nb4C4. However, for Nb3C4 a low-lying isomer containing a molecular C2 unit is assigned to the experimental IP rather than the depleted 2 × 2 × 2 nanocrystal isomer. For Nb4C5 and Nb4C6, interpretation is less straightforward, but results indicate isomers containing molecular C2 units are the lowest in energy, suggesting that carbon−carbon bonding is preferred when the number of carbon atoms exceeds the number of metal atoms. A double IP onset is observed for Nb4C3, which is attributed to ionization from the both the lowest energy singlet state and a meta-stable triplet state. This work further supports the notion that IPs can be used as a reliable validation for the geometries of metal–carbide clusters calculated by theory. 2008 Journal Article http://hdl.handle.net/20.500.11937/5894 10.1021/jp800691s American Chemical Society restricted |
| spellingShingle | Ionization-potentials Carbon clusters Electronic states Nanocrystals Reactivity Molecules Spectroscopy Transition-metal clusters Spectra Dynamics Dryza, V. Addicoat, M. Gascooke, J. Buntine, Mark Metha, G. Threshold photoionization and density functional theory studies of the niobium carbide clusters Nb3Cn (n=1-4) and Nb4Cn (n=1-6) |
| title | Threshold photoionization and density functional theory studies of the niobium carbide clusters Nb3Cn (n=1-4) and Nb4Cn (n=1-6) |
| title_full | Threshold photoionization and density functional theory studies of the niobium carbide clusters Nb3Cn (n=1-4) and Nb4Cn (n=1-6) |
| title_fullStr | Threshold photoionization and density functional theory studies of the niobium carbide clusters Nb3Cn (n=1-4) and Nb4Cn (n=1-6) |
| title_full_unstemmed | Threshold photoionization and density functional theory studies of the niobium carbide clusters Nb3Cn (n=1-4) and Nb4Cn (n=1-6) |
| title_short | Threshold photoionization and density functional theory studies of the niobium carbide clusters Nb3Cn (n=1-4) and Nb4Cn (n=1-6) |
| title_sort | threshold photoionization and density functional theory studies of the niobium carbide clusters nb3cn (n=1-4) and nb4cn (n=1-6) |
| topic | Ionization-potentials Carbon clusters Electronic states Nanocrystals Reactivity Molecules Spectroscopy Transition-metal clusters Spectra Dynamics |
| url | http://hdl.handle.net/20.500.11937/5894 |