Double and Triple Si–H–M Bridge Bonds: Matrix Infrared Spectra and Theoretical Calculations for Reaction Products of Silane with Ti, Zr, and Hf Atoms

Abstract

Infrared spectra of matrix isolated dibridged Si(μ-H)MH and tribridged Si(μ-H)MH molecules (M = Zr and Hf) were observed following the laser-ablated metal atom reactions with SiH during condensation in excess argon and neon, but only the latter species was observed with titanium. Assignments of the major vibrational modes, which included terminal MH, MH and hydrogen bridge Si-H-M stretching modes, were confirmed by the appropriate SiD isotopic shifts and density functional vibrational frequency calculations (B3LYP and BPW91). The Si-H-M hydrogen bridge bond is calculated as weak covalent interaction and compared with the C-H···M agostic interaction in terms of electron localization function (ELF) analysis and noncovalent interaction index (NCI) calculations. Furthermore, the different products of Ti, Zr, and Hf reactions with SiH are discussed in detail.

Charge-Inverted Hydrogen-Bridged Bond in HCa(μ-H)3E (E = Si, Ge, and Sn): Matrix Isolation Infrared Spectroscopic and Theoretical Studies

“…However, excited-state Be­( 1 P:2 s 2 p ) atoms react with silane to form both the classical insertion product HBeSiH 3 and the bridged structure molecules HBe­(μ-H) 3 Si due to the strong electron donor ability of Si–H bond . The triple-bridged structure molecules HM­(μ-H) 3 Si were also identified in the reaction of Ti and Ce atoms with silane. , While both the triple-bridged structure HM (μ-H) 3 Si and double-bridged structure H 2 M (μ-H) 2 Si molecules were produced in the reaction of Zr and Hf atoms with silane . In our previously reported work, ground-state boron atoms react with EH 4 (E = Si, Ge, and Sn) on annealing to produce the planar H 2 BEH 2 molecules with a double BE bond.…”

“…15 The triple-bridged structure molecules HM(μ-H) 3 Si were also identified in the reaction of Ti and Ce atoms with silane. 16,17 While both the triple-bridged structure HM (μ-H) 3 Si and double-bridged structure H 2 M (μ-H) 2 Si molecules were produced in the reaction of Zr and Hf atoms with silane. 17 In our previously reported work, ground-state boron atoms react with EH 4 (E = Si, Ge, and Sn) on annealing to produce the planar H 2 BEH 2 molecules with a double BE bond.…”

“…16,17 While both the triple-bridged structure HM (μ-H) 3 Si and double-bridged structure H 2 M (μ-H) 2 Si molecules were produced in the reaction of Zr and Hf atoms with silane. 17 In our previously reported work, ground-state boron atoms react with EH 4 (E = Si, Ge, and Sn) on annealing to produce the planar H 2 BEH 2 molecules with a double BE bond. Such planar molecules rearrange to E(μ-H) 2 BH 2 upon photolysis.…”