A molecular perspective on lithium-ammonia solutions.
A detailed molecular orbital (MO) analysis of the structure and electronic properties of the great variety of species in lithium-ammonia solutions is provided. In the odd-electron, doublet states we have considered: e-@(NH3)n (the solvated electron, likely to be a dynamic ensemble of molecules), the...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
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2009
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| _version_ | 1797097055006490624 |
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| author | Zurek, E Edwards, P Hoffmann, R |
| author_facet | Zurek, E Edwards, P Hoffmann, R |
| author_sort | Zurek, E |
| collection | OXFORD |
| description | A detailed molecular orbital (MO) analysis of the structure and electronic properties of the great variety of species in lithium-ammonia solutions is provided. In the odd-electron, doublet states we have considered: e-@(NH3)n (the solvated electron, likely to be a dynamic ensemble of molecules), the Li(NH3)4 monomer, and the [Li(NH3)4+.e-@(NH3)n] ion-pairs, the Li 2s electron enters a diffuse orbital built up largely from the lowest unoccupied MOs of the ammonia molecules. The singly occupied MOs are bonding between the hydrogen atoms; we call this stabilizing interaction H-->H bonding. In e-@(NH3)n the odd electron is not located in the center of the cavities formed by the ammonia molecules. Possible species with two or more weakly interacting electrons also exhibit H-->H bonding. For these, we find that the singlet (S=0) states are slightly lower in energy than those with unpaired (S=1, 2...) spins. TD-DFT calculations on various ion-pairs show that the three most intense electronic excitations arise from the transition between the SOMO (of s pseudosymmetry) into the lowest lying p-like levels. The optical absorption spectra are relatively metal-independent, and account for the absorption tail which extends into the visible. This is the source of Sir Humphry Davy's "fine blue colour" first observed just over 200 years ago. |
| first_indexed | 2024-03-07T04:50:13Z |
| format | Journal article |
| id | oxford-uuid:d4b0c463-5add-4303-a7dc-cc3ace671c02 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T04:50:13Z |
| publishDate | 2009 |
| record_format | dspace |
| spelling | oxford-uuid:d4b0c463-5add-4303-a7dc-cc3ace671c022022-03-27T08:20:29ZA molecular perspective on lithium-ammonia solutions.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:d4b0c463-5add-4303-a7dc-cc3ace671c02EnglishSymplectic Elements at Oxford2009Zurek, EEdwards, PHoffmann, RA detailed molecular orbital (MO) analysis of the structure and electronic properties of the great variety of species in lithium-ammonia solutions is provided. In the odd-electron, doublet states we have considered: e-@(NH3)n (the solvated electron, likely to be a dynamic ensemble of molecules), the Li(NH3)4 monomer, and the [Li(NH3)4+.e-@(NH3)n] ion-pairs, the Li 2s electron enters a diffuse orbital built up largely from the lowest unoccupied MOs of the ammonia molecules. The singly occupied MOs are bonding between the hydrogen atoms; we call this stabilizing interaction H-->H bonding. In e-@(NH3)n the odd electron is not located in the center of the cavities formed by the ammonia molecules. Possible species with two or more weakly interacting electrons also exhibit H-->H bonding. For these, we find that the singlet (S=0) states are slightly lower in energy than those with unpaired (S=1, 2...) spins. TD-DFT calculations on various ion-pairs show that the three most intense electronic excitations arise from the transition between the SOMO (of s pseudosymmetry) into the lowest lying p-like levels. The optical absorption spectra are relatively metal-independent, and account for the absorption tail which extends into the visible. This is the source of Sir Humphry Davy's "fine blue colour" first observed just over 200 years ago. |
| spellingShingle | Zurek, E Edwards, P Hoffmann, R A molecular perspective on lithium-ammonia solutions. |
| title | A molecular perspective on lithium-ammonia solutions. |
| title_full | A molecular perspective on lithium-ammonia solutions. |
| title_fullStr | A molecular perspective on lithium-ammonia solutions. |
| title_full_unstemmed | A molecular perspective on lithium-ammonia solutions. |
| title_short | A molecular perspective on lithium-ammonia solutions. |
| title_sort | molecular perspective on lithium ammonia solutions |
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