Ab initio study of the reactions of Zn(1S, 3P, and 1P) with SiH4

Abstract

The reactions of Zn(1S, 3P, and 1P) with SiH4 have been studied through multiconfigurational self-consistent field (with relativistic effective core potentials) followed by extensive variational and perturbational second-order multireference Möller–Plesset configuration interaction by perturbation selected by iterative process calculations using extended Gaussian basis sets. The Zn atom in the 3P(4s14p1) state breaks the Si–H bond of silane spontaneously, leading directly to the ZnH+SiH3 final products, in agreement with experimental results. The 1P(4s14p1) Zn atom is also inserted in the Si–H bond and the corresponding interaction surface shows an avoided crossing with the lowest-lying X 1A′ potential surface, adiabatically correlated with the Zn(1S:4s2)+SiH4 reactants. This interaction leads also to the ZnH+SiH3 products. The structure of the HZnSiH3 intermediate product was carefully studied as well as the dissociation channels leading to the ZnH+SiH3 and H+ZnSiH3 products. Accurate energy differences between these species are also reported. The qualitative difference in the behavior of the 3P(4s14p1) Zn reaction with methane and silane has been explained by analyzing the corresponding potential energy surfaces; the present results confirm the C–H bond steric hindrance hypothesis advanced by Wang et al. [J. Chem. Phys. 104, 9401 (1996)].

Ab initio studies of the reactions of M(1S,3P, and 1P) with GeH4 (M=Cd, Hg)

“…The strategy to obtain the reaction pathways for the M( 1 S, 3 P, 1 P)ϩGeH 4 (MϭCd, Hg) interactions was that used previously by our group to study the activation of silane by the same metal atoms 16 and long before by a zinc atom 25 which, in turn, was based on the original proposal by Chaquin et al 44 The initial approach ͑starting from 20 a.u.͒ of the metal atom to one of the Ge-H bonds was done in C s symmetry on a plane containing the germanium atom and two hydrogen atoms. All the angles and distances defining the molecular geometry of the HMGeH 3 intermediates are presented in Fig.…”

“…These eight geometric parameters were varied according to the scheme used to describe in full detail the insertion into the Si-H bond of silane by Zn in Ref. 25 and Cd and Hg in Ref. 16.…”

“…16,[24][25][26] However, to our knowledge, with the exception of the experimental study over the Mg-GeH 4 interaction carried out by Breckenridge and Umemoto, 17 there are no other studies, neither experimental nor theoretical, dealing with the interaction of a metal atom with germane. As can be seen from the previous paragraphs, the study of the activation by excited metallic atoms of Ge-H bonds of the GeH 4 molecule and/or in equivalent molecular complexes where the Ge-H bond is present, is a topic of considerable interest from a variety of theoretical and practical aspects.…”

Landau–Zener theory for avoided crossings applied to the gallium–silane reactions

“…In our work 3, the angle θ between silicon–gallium–hydrogen is actually the relevant reaction parameter instead of the distance. The process of finding the potential energy curve versus the angle θ has been widely applied to atom–molecule interactions 4–27. However, it is until now that has been possible to accomplish calculations of nonadiabatic crossing of energy levels when the energy is a function of the angle.…”

Ab initio study of the insertion reactions of Sc+(1D) with HF, HCl, H2O, H2S, NH3, PH3, CH4, and SiH4

“…Because the radical and atom (light atom) insertion into an ROH bond can form many stable compounds, such as hybrids, many have been studied theoretically. The insertion reactions of the radicals 1 CH, 1 NH, 1 SiH, 1 PH with HF, HCl, H 2 O, H 2 S, NH 3 , and PH 3 have been studied by ab initio molecular orbital theory [9 -11] and the atoms C, N, Mg, Al, Si, Cu, Zn, Rh, Ni, and Hg insertion into ROH(RAC, N, O, F, Si, P, S, and Cl) were also studied [12][13][14][15][16][17][18][19]. The mechanisms of the dehydrogenation reaction involving ions were widely investigated theoretically, such as N ϩ , Si ϩ , P ϩ , Al ϩ , Sc ϩ , Y ϩ , Ti ϩ with CH 4 , NH 3 The insertion reaction step connected directly to the particle reaction with RH n molecules is an adiabatic or nonadiabatic reaction, and the key step to further reaction such as dehydrogenation.…”