RT info:eu-repo/semantics/article
T1 A Bridging bis-Allyl Titanium Complex: Mechanistic Insights into the Electronic Structure and Reactivity
A1 Carbó, Jorge J.
A1 Gómez Pantoja, María
A1 Martín Alonso, Avelino
A1 Mena Montoro, Miguel
A1 Ricart, Josep M.
A1 Salom Catalá, Antoni
A1 Santamaría Angulo, Cristina
K1 Química
K1 Chemistry
AB Treatment of the dinuclear compound [{Ti(η5-C5Me5)Cl2}2(μ-O)] with allylmagnesium chloride provides the formation of the allyltitanium(III) derivative [{Ti(η5-C5Me5)(μ-C3H5)}2(μ-O)] (1), structurally identified by single-crystal X-ray analysis. Density functional theory (DFT) calculations confirm that the electronic structure of 1 is a singlet state, and the molecular orbital analysis, along with the short Ti −Ti distance, reveal the presence of a metal −metal single bond between the two Ti(III) centers. Complex 1 reacts rapidly with organic azides, RN3 (R = Ph, SiMe3), to yield the allyl μ-imido derivatives [{Ti(η5-C5Me5)(CH2CH=CH2)}2(μ-NR)(μ-O)] [R = Ph(2), SiMe3(3)] along with molecular nitrogen release. Reaction of 2 and 3 with H2 leads to the μ-imido propyl species [{Ti(η5-C5Me5)(CH2CH2CH3)}2(μ-NR)(μ-O)] [R = Ph(4), SiMe3(5)]. Theoretical calculations were used to gain insight into the hydrogenation mechanism of complex 3 and rationalize the lower reactivity of 2. Initially, the μ-imido bridging group in these complexes activates the H2 molecule via addition to the Ti −N bonds. Subsequently, the titanium hydride intermediates induce a change in hapticity of the allyl ligands, and the nucleophilic attack of the hydride to the allyl groups leads to metallacyclopropane intermediates. Finally, the proton transfer from the amido group to the metallacyclopropane moieties affords the propyl complexes 4 and 5.
SN 0020-1669
YR 2019
FD 2019-08-26
LK http://hdl.handle.net/10017/38966
UL http://hdl.handle.net/10017/38966
LA eng
NO Ministerio de Ciencia, Innovación y UniversidadesUniversidad de AlcaláGeneralitat de Catalunya
DS MINDS@UW
RD 19-abr-2024