Unprecedented flexibility of the >Ti=Si< group for the addition of H2.
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.
Maj
Lukasz
L
Laboratory of Intermolecular Interactions, Department of Chemistry, University of Warsaw, Pasteur 1, 02093, Warsaw, Poland.
Grochala
Wojciech
W
D003198:Computer Simulation; D006859:Hydrogen / Q000737:chemistry*; D008956:Models, Chemical; D011789:Quantum Theory; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
D006859:Hydrogen; D014025:Titanium; D012825:Silicon