Conversion of neutral C₂COC₂ to C₄CO. Potential interstellar molecules
| dc.contributor.author | Dua, S. | |
| dc.contributor.author | Blanksby, S. | |
| dc.contributor.author | Bowie, J. | |
| dc.date.issued | 2000 | |
| dc.description | Copyright © 2000 Elsevier Science B.V. All rights reserved. | |
| dc.description.abstract | Both [C<inf>4</inf>CO]<sup>-.</sup> and [C<inf>2</inf>COC<inf>2</inf>]<sup>-.</sup> are formed in the ion source of a VG ZAB 2HF mass spectrometer by the respective processes HO<sup>-</sup> + Me<inf>3</inf>Si-C≡C-C≡CO-CMe<inf>3</inf> → [C<inf>4</inf>CO]<sup>-.</sup> + Me<inf>3</inf>SiOH + Me<inf>3</inf>C<sup>.</sup>, and Me<inf>3</inf>Si-C≡CO-C-SiMe<inf>3</inf> + SF<inf>6</inf> + e → [C<inf>2</inf>COC<inf>2</inf>]<sup>-.</sup> + 2Me<inf>3</inf>SiF + SF<inf>4</inf>. The second synthetic pathway involves a double desilylation reaction similar to that first reported by Squires. The two radical anion isomers produce different and characteristic charge reversal spectra upon collisional activation. In contrast, following collision induced charge stripping, both radical anions produce neutral C<inf>4</inf>CO as evidenced by the identical neutralisation reionisation (<sup>-</sup>NR<sup>+</sup>) spectra. The exclusive rearrangement of C<inf>2</inf> <sup>13</sup>COC<inf>2</inf> to C<inf>4</inf> <sup>13</sup>CO indicates that <sup>12</sup>C-O bond formation is not involved in the reaction. Ab initio calculations (at the RCCSD(T)/aug-cc-pVDZ//B3LYP/6-31G* level of theory) have been used to investigate the reaction coordinates on the potential surfaces for both singlet and triplet rearrangements of neutral C<inf>2</inf>COC<inf>2</inf>. Singlet C<inf>2</inf>COC<inf>2</inf> is less stable than singlet C<inf>4</inf>CO by 78.8 kcal mol<sup>-1</sup> and requires only 8.5 kcal mol<sup>-1</sup> of additional energy to effect conversion to C<inf>4</inf>CO by a rearrangement sequence involving three C-C ring opening/cyclisation steps. (C) 2000 Elsevier Science B.V. | |
| dc.description.statementofresponsibility | Suresh Dua, Stephen J. Blanksby and John H. Bowie | |
| dc.description.uri | http://www.elsevier.com/wps/find/journaldescription.cws_home/500847/description#description | |
| dc.identifier.citation | International Journal of Mass Spectrometry, 2000; 195/196:45-54 | |
| dc.identifier.doi | 10.1016/S1387-3806(99)00188-8 | |
| dc.identifier.issn | 1387-3806 | |
| dc.identifier.issn | 1873-2798 | |
| dc.identifier.uri | http://hdl.handle.net/2440/4507 | |
| dc.language.iso | en | |
| dc.publisher | Elsevier Science BV | |
| dc.relation.grant | ARC | |
| dc.source.uri | https://doi.org/10.1016/s1387-3806(99)00188-8 | |
| dc.title | Conversion of neutral C₂COC₂ to C₄CO. Potential interstellar molecules | |
| dc.title.alternative | Conversion of neutral C(2)COC(2) to C(4)CO. Potential interstellar molecules | |
| dc.type | Journal article | |
| pubs.publication-status | Published |