Matrix-Infrared Spectra and Structures of HM–SiH₃ (M = Ge, Sn, Pb, Sb, Bi, Te Atoms)

Abstract

The reactions of Ge, Sn, Pb, Sb, Bi, and Te atoms with silane molecules were studied using matrix-isolation Fourier transform infrared spectroscopy and density functional theoretical (DFT) calculations. All metals generate the inserted complexes HM-SiH, which were stabilized in an argon matrix, while HM═SiH and HM≡SiH were not observed. DFT and CCSD(T) calculations show the insertion complex HM-SiH is the most stable isomer with a near right angle H-M-Si moiety. However, silydene complexes HM═SiH (M = C, Si) were calculated and identified as the most stable complexes with the lighter elements. The bonding difference is mainly due to relativistic effects, which is that for heavier metal atoms valence s and p orbitals have a lower tendency to form hybrid orbitals.

Matrix Infrared Spectra and Theoretical Calculations of Fluoroboryl Complexes F2B–MF (M = C, Si, Ge, Sn and Pb)

“…For group 14 atoms, carbon is special since it has almost equal 2s and 2p orbital radial expectation values . However, for the heavier atoms, the considerable value difference between valence s and p atomic orbital increase, and the value differences are 0.39, 0.48, 0.57, and 0.79 Å for Si, Ge, Sn, and Pb, respectively, − which was mainly caused by relativistic effect. Obviously there is a lower tendency to form hybrid orbital between s and p orbital for the heavier atoms.…”

“…In our atoms-in-molecules (AIM) picture (Figure ) the bond critical point (BCP) between B and C, Si, Ge, Pb locates in the region with negative Laplacian value (∇ 2 ρ cp = −0.222 for B–C, −0.137 for B–Si, −0.095 for B–Ge, 0.0097 for B–Sn, and −0.029 for B–Pb). As pointed out in the AIM methodology, , the classification of the interaction is defined by the sign of ∇ 2 ρ cp . Thus, the interactions between B and Si, Ge, and Pb are in the region of the covalent bond.…”

“…The negative value of the local energy density H (r) = −0.02899 for B–Sn indicates the covalent bonding character . Moreover, the |V cp |/ G cp value is a good indicator for the bond properties, which when smaller than 1 indicates ionic bond and large than 2 often manifests a covalent bond. , The |V cp |/ G cp value is 2.35, 2.84, 2.92, 1.72, and 2.76 for the CP of B–M bonds (M = C, Si, Ge, Sn, and Pb, respectively), indicating an increase in covalent character from C to Ge, a decrease from Ge to Sn, and an increase again from Sn to Pb.…”

Access to Monomeric Hydridoplumbate(II) Anions with Remarkable Thermostability

“…with unsaturated molecules 5,6 . Transient lead hydride species can also be generated through the reaction of laser-ablated Pb atoms with, for example, H 2 7 , CH 4 8 , and SiH 4 at low temperature 9 , and can be observed using infrared spectroscopy. Per their recent theoretical results, Toro-Labbé et al predicted that a βdiketiminato ligand-supported lead(II) hydride complex is superior to its Ge(II) and Sn(II) analogues as a catalyst for CO 2 activation 10 .…”

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

“…Compared with methane, the reactions of its heavier analogues (SiH 4 , GeH 4 , and SnH 4 ) with naked metal atoms using the matrix isolation technique have been much less reported. Silyl metal hydride molecules HMSiH 3 were identified in the reaction of group IIB metal atoms (Zn, Cd, and Hg) and p-block metal atoms (Al, Ga, In, Ge, Sn, Pb, Sb, Bi, and Te) − with silane in solid argon matrix. Except for the silyl metal hydride molecules HMSiH 3 , low-spin H 3 MoSiH and H 3 WSiH molecules with triple MoSi and WSi bonds were identified in the reaction of group VIB metal atoms (Cr, Mo, and W) with SiH 4 .…”