title: Unprecedented flexibility of the >Ti=Si< group for the addition of H2.
abstract: We show using DFT calculations that a coordinatively unsaturated >Ti=Si< group exhibits an unprecedented flexibility for the reversible addition of dihydrogen. The H2 attachment may lead to a variety of hydrogenated species (near-equivalent in energy), which contain three-center Ti...H...Si and terminal Ti-H and Si-H bonds. The >Ti=Si< moiety also exhibits a particularly low electronic barrier for heterolytic H2 attachment (approximately 0.0 eV) and beneficial thermodynamics of this process. One important path leads to the kinetically preferred H-Ti...H...Si isomer (at -0.5 eV with respect to the substrates, denoted II), which is capable of a subsequent low-barrier H2 release. Chemically pre-engineered compounds containing the >Ti=Si< grouping might be used for efficient H2 transfer catalysis in organic and inorganic hydrogenations, and for charging/discharging of the hydrogen storage materials.
authors.affiliation: Laboratory of Intermolecular Interactions, Department of Chemistry, University of Warsaw, Pasteur 1, 02093, Warsaw, Poland.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Maj
authors.forename: Wojciech
authors.initials: W
authors.lastname: Grochala
mesh_terms: D003198:Computer Simulation; D006859:Hydrogen / Q000737:chemistry*; D008956:Models, Chemical; D011789:Quantum Theory; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D006859:Hydrogen; D014025:Titanium; D012825:Silicon