Study of the Isomers of Isoelectronic C-4, (C3B)(-), and (C3N)(+): Rearrangements through Cyclic Isomers
Optimized structures of the isoelectronic cumulenes (CCCB)(-), CCCC, and (CCCN)(+) and of their isomers formed by rearrangement have been calculated at the B3LYP/6-311+ G(3df) level of theory with relative energies and electronic states determined at the CCSD(T)/aug-cc-pVTZ level of theory. The grou...
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| Format: | Journal Article |
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American Chemical Society
2009
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| Online Access: | http://hdl.handle.net/20.500.11937/34297 |
| _version_ | 1848754185159311360 |
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| author | Wang, Tianfang Buntine, Mark Bowie, John |
| author_facet | Wang, Tianfang Buntine, Mark Bowie, John |
| author_sort | Wang, Tianfang |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Optimized structures of the isoelectronic cumulenes (CCCB)(-), CCCC, and (CCCN)(+) and of their isomers formed by rearrangement have been calculated at the B3LYP/6-311+ G(3df) level of theory with relative energies and electronic states determined at the CCSD(T)/aug-cc-pVTZ level of theory. The ground states of CCCC and (CCCN)(+) are triplets, whereas the ground state of (CCCB)(-) is a quasi-linear singlet structure that is only 0.6 kcal mol(-1) more negative in energy than the linear triplet. When energized, both triplet and singlet CCCC cyclize to planar rhomboids, of which the singlet is the lowest-energy configuration. Ring-opening of rhomboid C-4 reforms CCCC with the carbons partially randomized. Similar rear-rangements occur for (CCCB)(-) and (CCCN)(+), but the reactions are different in the detail. In the case of (CCCN)(+), rearrangement of atoms is supported both experimentally and theoretically. Because (CCCB)(-) and (CCCN)(+) are not symmetrical, two fully cyclized forms are possible; the one more resembling a rhomboid structure is called a "kite" structure, and the other is called a "fail" structure. The rearrangement of (CCCB)(-) is more favored via the triplet with equilibrating kite and fan structures being formed, whereas the singlet (CCCN)(+) ring closes to give the singlet kite structure, which may ring open to give a mixture of (CCCN)(+) and (CCNC)(+). Intersystem crossing may occur for the triplet and singlet forms of CCCC and (CCCB)(-) but not for (CCCN)(+). |
| first_indexed | 2025-11-14T08:36:23Z |
| format | Journal Article |
| id | curtin-20.500.11937-34297 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:36:23Z |
| publishDate | 2009 |
| publisher | American Chemical Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-342972017-09-13T16:07:20Z Study of the Isomers of Isoelectronic C-4, (C3B)(-), and (C3N)(+): Rearrangements through Cyclic Isomers Wang, Tianfang Buntine, Mark Bowie, John NEGATIVE-IONS CORRELATED MOLECULAR CALCULATIONS SPECTRA C3N+ RHOMBOIDAL SIC3 GAUSSIAN-BASIS SETS SMALL CARBON CLUSTERS INTERSTELLAR AB-INITIO GAS-PHASE Optimized structures of the isoelectronic cumulenes (CCCB)(-), CCCC, and (CCCN)(+) and of their isomers formed by rearrangement have been calculated at the B3LYP/6-311+ G(3df) level of theory with relative energies and electronic states determined at the CCSD(T)/aug-cc-pVTZ level of theory. The ground states of CCCC and (CCCN)(+) are triplets, whereas the ground state of (CCCB)(-) is a quasi-linear singlet structure that is only 0.6 kcal mol(-1) more negative in energy than the linear triplet. When energized, both triplet and singlet CCCC cyclize to planar rhomboids, of which the singlet is the lowest-energy configuration. Ring-opening of rhomboid C-4 reforms CCCC with the carbons partially randomized. Similar rear-rangements occur for (CCCB)(-) and (CCCN)(+), but the reactions are different in the detail. In the case of (CCCN)(+), rearrangement of atoms is supported both experimentally and theoretically. Because (CCCB)(-) and (CCCN)(+) are not symmetrical, two fully cyclized forms are possible; the one more resembling a rhomboid structure is called a "kite" structure, and the other is called a "fail" structure. The rearrangement of (CCCB)(-) is more favored via the triplet with equilibrating kite and fan structures being formed, whereas the singlet (CCCN)(+) ring closes to give the singlet kite structure, which may ring open to give a mixture of (CCCN)(+) and (CCNC)(+). Intersystem crossing may occur for the triplet and singlet forms of CCCC and (CCCB)(-) but not for (CCCN)(+). 2009 Journal Article http://hdl.handle.net/20.500.11937/34297 10.1021/jp907484z American Chemical Society restricted |
| spellingShingle | NEGATIVE-IONS CORRELATED MOLECULAR CALCULATIONS SPECTRA C3N+ RHOMBOIDAL SIC3 GAUSSIAN-BASIS SETS SMALL CARBON CLUSTERS INTERSTELLAR AB-INITIO GAS-PHASE Wang, Tianfang Buntine, Mark Bowie, John Study of the Isomers of Isoelectronic C-4, (C3B)(-), and (C3N)(+): Rearrangements through Cyclic Isomers |
| title | Study of the Isomers of Isoelectronic C-4, (C3B)(-), and (C3N)(+): Rearrangements through Cyclic Isomers |
| title_full | Study of the Isomers of Isoelectronic C-4, (C3B)(-), and (C3N)(+): Rearrangements through Cyclic Isomers |
| title_fullStr | Study of the Isomers of Isoelectronic C-4, (C3B)(-), and (C3N)(+): Rearrangements through Cyclic Isomers |
| title_full_unstemmed | Study of the Isomers of Isoelectronic C-4, (C3B)(-), and (C3N)(+): Rearrangements through Cyclic Isomers |
| title_short | Study of the Isomers of Isoelectronic C-4, (C3B)(-), and (C3N)(+): Rearrangements through Cyclic Isomers |
| title_sort | study of the isomers of isoelectronic c-4, (c3b)(-), and (c3n)(+): rearrangements through cyclic isomers |
| topic | NEGATIVE-IONS CORRELATED MOLECULAR CALCULATIONS SPECTRA C3N+ RHOMBOIDAL SIC3 GAUSSIAN-BASIS SETS SMALL CARBON CLUSTERS INTERSTELLAR AB-INITIO GAS-PHASE |
| url | http://hdl.handle.net/20.500.11937/34297 |