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Are the anions MeO(CO) n − (n = 1 and 2) methoxide anion donors in the gas phase? A theoretical investigation
Author(s) -
Wang Tianfang,
Eichinger Peter C. H.,
Dua Suresh,
Bowie John H.
Publication year - 2010
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.4586
Subject(s) - chemistry , methoxide , medicinal chemistry , hydride , ion , gas phase , metal , organic chemistry
Abstract1. The anions CH 3 O‐ – CO and CH 3 OCO‐ – CO are both methoxide anion donors. The processes CH 3 O‐ – CO → CH 3 O – + CO and CH 3 OCO—CO → CH 3 O – + 2CO have ΔG values of +8 and −68 kJ mol −1 , respectively, at the CCSD(T)/6‐311++G(2d, 2p)//B3LYP/6‐311++G(2d,2p) level of theory. 2. The reactions CH 3 OCOCO 2 – → CH 3 OCO 2 – + CO (ΔG = −22 kJ mol −1 ) and CH 3 COCH(O – )CO 2 CH 3 → CH 3 COCH(O – )OCH 3 + CO (ΔG = +19 kJ mol −1 ) proceed directly from the precursor anions via the transition states (CH 3 OCO…CO 2 ) – and (CH 3 COCHO…CH 3 OCO) – , respectively. 3. Anion CH 3 COCH(O – )CO 2 CH 3 undergoes methoxide anion transfer and loss of two molecules of CO in the reaction sequence CH 3 COCH(O – )CO 2 CH 3 → CH 3 CH(O – )COCO 2 CH 3 → [CH 3 CHO (CH 3 OCO‐ – CO)] → CH 3 CH(O – )OCH 3 + 2CO (ΔG = +9 kJ mol −1 ). The hydride ion transfer in the first step is a key feature of the reaction sequence. Copyright © 2010 John Wiley & Sons, Ltd.