Тип публикации: статья из журнала
Год издания: 2011
Идентификатор DOI: 10.1016/j.jorganchem.2011.06.051
Ключевые слова: Density functional, Vinylidene, Manganese carbonyl, Iron carbonyl, Binuclear complex, Carbonylation, A-density, Activation barriers, Binuclear complexes, Computational studies, Conjugation effects, E-forms, Hybrid density functional method, Manganese complexes, Phenyl group, Phenyl rings, Single-step, Transition state, Vinylidene complexes, Activation energy, Isomers, Manganese, Stereochemistry, Iron compounds
Аннотация: Treating the phenylvinyldene manganese complex Cp(CO)(2)Mn=C(1)=C(2)HPh, 1, with [Fe(CO)(4)] yields the binuclear mu-vinylidene complex Cp(CO)(2)MnFe(mu-C(1)=C(2)HPh)(CO)(4), 2, that further isomerizes to the carbonylated product eta(4)-[Cp(CO)(2)MnC(1)(CO)C(2)HPh]Fe(CO)(3), 3. In a computational study of the mechanism using a hybrПоказать полностьюid density functional method, we considered two stereoisomers for species 2 and 3 where the phenyl group at center C(2) is oriented in cis (E form) or trans (Z form) fashion to the Cp(CO)(2)Mn unit. Isomers 2E and 2Z were calculated to be degenerate whereas the experimentally detected species 3E is 8 kcal/mol more stable than its isomer 3Z. The two-step pathway 1 -> 2Z -> 3E was calculated to be the lowest-energy route with the highest activation barrier at 12 kcal/mol. The activation energy of the alternative single-step pathway 1 -> 3E is 19 kcal/mol. We rationalized the stabilization of the ground state of 3E and the transition states leading to or starting from isomer 2Z as conjugation effect between the Mn-C=C metallaallene fragment and the co-planar phenyl ring. (C) 2011 Elsevier B. V. All rights reserved.
Журнал: JOURNAL OF ORGANOMETALLIC CHEMISTRY
Выпуск журнала: Vol. 696, Is. 22
Номера страниц: 3445-3453
ISSN журнала: 0022328X
Место издания: LAUSANNE
Издатель: ELSEVIER SCIENCE SA