title: Two-State Reactivity Mechanism of Benzene C-C Activation by Trinuclear Titanium Hydride.
abstract: The cleavage of inert C-C bonds is a central challenge in modern chemistry. Multinuclear transition metal complexes would be a desirable alternative because of the synergetic effect of multiple metal centers. In this work, carbon-carbon bond cleavage and rearrangement of benzene by a trinuclear titanium hydride were investigated using density functional theory. The reaction occurs via a novel "two-state reactivity" mechanism. The important elementary steps consist of hydride transfer, benzene coordination, dehydrogenation, oxidative addition, hydride-proton exchange, and reductive elimination. Most importantly, the ground-state potential energy surface switches from nearly degenerate triplet and antiferromagnetic singlet states to a closed-shell singlet state in the dearomatization of benzene, which effectively decreases the activation barrier. Furthermore, the roles of the transition metal centers and hydrides were clarified.
authors.affiliation: Institute of Functional Materials Chemistry and Local United Engineering Lab for Power Battery, Faculty of Chemistry, Northeast Normal University , Changchun 130024, P. R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhu
authors.affiliation: Institute of Functional Materials Chemistry and Local United Engineering Lab for Power Battery, Faculty of Chemistry, Northeast Normal University , Changchun 130024, P. R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Guan
authors.affiliation: Institute of Functional Materials Chemistry and Local United Engineering Lab for Power Battery, Faculty of Chemistry, Northeast Normal University , Changchun 130024, P. R. China.
authors.forename: Li-Kai
authors.initials: LK
authors.lastname: Yan
authors.affiliation: Institute of Functional Materials Chemistry and Local United Engineering Lab for Power Battery, Faculty of Chemistry, Northeast Normal University , Changchun 130024, P. R. China.
authors.forename: Zhong-Min
authors.initials: ZM
authors.lastname: Su