Реферат: The reactions of methane and dihydrogen molecules with the cations [(η5-C5H5)2MCH3]+ (1) and [(η5-C5H5)2MH]+ (3) (M=Zr, Ti) have been investigated by gradient-corrected density functional calculations. In the case of CH4, the active cationic center of 1 or 3 attracts the substrate molecule first to form an agostic complex in which its C-H bond is already somewhat weakened. The σ-bonded ligand exchange reaction in the system 1+CH4 proceeds through a symmetric transition state with an activation barrier of 15.0 kcal mol−1 (11.6 kcal mol−1) for the Zr (Ti) complex. Hydrogen reacts with 1 exothermally, ΔH0=−7.1 kcal mol−1 (−8.6 kcal mol−1) for Zr (Ti), yielding 3 and CH4 without an activation barrier. These theoretical results give insight into the mechanism of H/D exchange in methane in the presence of Ziegler–Natta-type catalysts observed experimentally by Grigoryan et al. It is shown that organometallic cationic complexes of Zr(IV) and Ti(IV) may prove to be promising systems for C-H and H-H bond activation under mild conditions.

Библиографическая ссылка: Ustynyuk Y.A. , Ustynyuk L.Y. , Laikov D.N. , Lunin V.V.
Activation of CH4 and H2 by zirconium(IV) and titanium(IV) cationic complexes. Theoretical DFT study
Journal of Organometallic Chemistry. 2000. V.597. N1-2. P.182-189. DOI: 10.1016/s0022-328x(99)00686-5 WOS Scopus OpenAlex

Идентификаторы БД:

Web of science:	WOS:000085941200026
Scopus:	2-s2.0-0001500411
OpenAlex:	W2028031497

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БД	Цитирований
OpenAlex	65
Scopus	72

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