A study of the reactions of chlorine and fluorine atoms with SiH2Cl2 and SiHCl3, with ultraviolet photoelectron spectroscopy

Halogenated silanes, radicals, and cations: Theoretical predictions on ionization energies, structures and potential energy surfaces of cations, proton affinities, and enthalpies of formation

“…Both IE a (SiCl 3 ) differ significantly from our G3(CC) prediction of 7.85 eV and previous G2(MP2) of 7.84 eV [51]. Neither the IE a (SiHCl 2 ) = 7.90 ± 0.10 eV by Dyke et al [77] is reliable, even though it agrees accidentally with our G3(CC) of 7.81 eV. Murthy and Beauchamp [45,46] reported an IE a (SiH 2 Cl) = 7.66 ± 0.23 eV using f H • (SiH 2 Cl + ) obtained from ion-molecule reaction kinetics and f H • (SiH 2 Cl) from BAC-MP4 prediction [48], being lower than G3(CC) value of 7.90 eV.…”

“…Dyke et al [77] also reported a value of 8.05 ± 0.10 eV from IE Expt − (IE MP2 ), where IE Expt was the experimental vertical IE from photoelectron spectroscopy and (IE MP2 ) was difference between vertical and adiabatic IE a at MP2/6-31G(d,p) level. The correction (IE MP2 ) was rather rough and unlikely valid.…”

“…Experimental measurements were available only to SiH 3 , SiF 3 , SiHCl 2 and SiCl 3 [31,40,44,77], and theoretical studies were limited to fluorosilyls and SiCl 3 [29,51,54]. Present G3(CC) represents the first systematic study on this system.…”

“…Present G3(CC) represents the first systematic study on this system. G3(CC) calculations show strong effects from F-substitution with increased IE a from SiH 2 F (8.12 eV) to SiF 3 (9.17 eV), very small effect from Cl- Values are obtained from: a JANAF table [94]; b photoionization [31]; c Ion chemistry [38]; d BAC-MP4/6-31G(d,p) [29]; e Ion chemistry [40]; f Ion chemistry [41]; g Rydberg series [32]; h CCSD(T)/CBS [54]; i Ion chemistry [43]; j Ion chemistry [44]; k Rydberg series [33]; l Photoionization mass spectrometry [35]; m CCSD(T)/AVQZ calculation [51]; n Electron impact ionization [76]; o Rydberg series [37]; p Photoelectron spectroscopy [72]; q CCSD(T)/CBS [60]; r Electron impact ionization [73]; s Photoelectron spectroscopy [74]; t G2(MP2) calculation [51]; u Estimation from photoionization [75]; v Rydberg series [36]; w Photoelectron spectroscopy [78]; x Ion-molecule reaction [45,46]; y Estimation from photoelectron spectroscopy [77]. substitution with small change of IE a from SiH 2 Cl (7.90 eV) to SiCl 3 (7.85 eV), and from Br-substitution with slightly decreased IE a from SiH 2 Br (7.83 eV) to SiBr 3 (7.63 eV).…”

Investigation of Hg(SiMe3)2 and Me3Si radical by photoelectron spectroscopy and theoretical methods

“…Various photoionization studies in relation to silicon containing radicals including H 3 Si [3], Cl 3 Si and HCl 2 Si [4] can be found in the literature. Structure and chemical properties of Me 3 Si radical is also discussed in detail [5].…”