Spectrum of SiH2

Dubois, I.; Herzberg, G.; Verma, R. D.

doi:10.1063/1.1701609

Cited by 112 publications

(29 citation statements)

References 4 publications

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“…[4][5][6] A number of spectroscopic studies has been devoted to this transient species. SiH 2 was first identified by Dubois 30 years ago 7,8 by detection of its electronic absorption spectrum in the visible range. It was produced by photolysis of phenylsilane and the spectrum was obtained with a path length of 48 m and photographed at high dispersion.…”

Section: Introductionmentioning

confidence: 99%

“…The accuracy of the line positions is about 0.01 cm Ϫ1 , which is intermediate between the high resolution infrared experiment of Yamada et al 10 and the previous data from Dubois. 7,8 We also present a more comprehensive determination of the rotational constants of the ͑0,0,0͒ level in the electronic ground state, performed by combining all three sets of data with appropriate weights in a single refinement process.…”

Section: Introductionmentioning

confidence: 99%

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Absorption spectroscopy of SiH2 near 640 nm

Escribano

Campargue

1998

The Journal of Chemical Physics

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The Ã 1 B 1 -X 1 A 1 absorption spectrum of SiH 2 has been observed using intracavity laser absorption spectroscopy with an equivalent path length of up to 13.0 km and the Ã 1 B 1 (0, 0, 0)-X 1 A 1 (0, 0, 0) band near 640 nm recorded for the first time. The silylene radical was generated in a continuous discharge in a flowing mixture of silane in argon, giving a concentration of the order of 10 10 SiH 2 /cm 3 . The spectrum spans the region between 15350 and 16100 cm Ϫ1 . Rotational transitions have been assigned to levels up to Jϭ16 and K a ϭ9, with ⌬K a up to 5, ⌬K c up to 4. Perturbations have been detected in the spectrum, due to Renner-Teller and spin-orbit interactions between both electronic states and the 3 B 1 state, predicted to be between them. However, the strength of the irregular perturbations affecting the rotational states of Ã 1 B 1 ͑0,0,0͒ state is found to be much weaker than that affecting the other (0, v 2 Ј, 0) levels previously studied. The analysis of the spectrum has allowed the determination of the rotational constants of the 1 B 1 ͑0,0,0͒ level, and a new estimation of those of the vibrational and electronic ground state. The geometry of the excited electronic level has also been determined for the first time from accurate experimental data. A change in the structure of this molecule takes place with this transition, the equilibrium angle opening from 92°to 122.4°, while the bond distance is reduced from 1.51 to 1.485 Å.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Absorption spectroscopy of SiH2 near 640 nm

Escribano

Campargue

1998

The Journal of Chemical Physics

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“…Electronic and steric effects may affect multiplicity and produce triplet silylene . For instance, bulky and electropositive substituents can compensate the increment in promotion energy by increasing the p character of Si valence orbital . The first triplet ground state silylene was studied by Gordon .…”

Section: Introductionmentioning

confidence: 99%

“…[11][12][13] For instance, bulky and electropositive substituents can compensate the increment in promotion energy by increasing the p character of Si valence orbital. [14] The first triplet ground state silylene was studied by Gordon. [15] Later, Gaspar studied triplet dimethylsilylene and disilylsilylene using DFT and ab initio methods.…”

Section: Introductionmentioning

confidence: 99%

Toward triplet disilavinylidenes: A Hammett electronic survey for substituent effects on singlet‐triplet energy gaps of silylenes by DFT

Ayoubi‐Chianeh

Kassaee

2019

J of Physical Organic Chem

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To reach for novel triplet silylenes, para‐ and meta‐R‐1,1‐diphenyldisilavinylidenes with various electron donating and withdrawing groups (EDGs and EWGs, respectively) are compared and contrasted using the B3LYP/6‐311++g** method, where para silylenes consist of 1H, 2boldCHbold3, 3OH, 4boldNHbold2, 5F, 6Cl, 7boldCFbold3, 8CHO, 9boldNMebold2, and 10boldNObold2, whereas their meta isomers are bold2′boldCHbold3, 3′OH, bold4′boldNHbold2, 5′F, 6′Cl, bold7′boldCFbold3, 8′CHO, bold9′boldNMebold2, and bold10′boldNObold2. The overall trend for triplet tendency of the latter group based on their singlet‐triplet energy gap (ΔEs‐t) is 3′OH > bold4′boldNHbold2 > 1H > bold2′boldCHbold3 > bold9′boldNMebold2 > 8′CHO > 5′F > 6′Cl > bold7′boldCFbold3 > bold10′boldNObold2 while that for the former, para series is 9boldNMebold2 > 4boldNHbold2 > 3OH > 2boldCHbold3 > 5F > 6Cl > 1H > 7boldCFbold3 > 8CHO > 10boldNObold2. Plotting disilavinylidenes ΔEs‐t, against their corresponding Hammett substituent constants (σp or σm) shows rather significant ρ factors of −2.07 and −1.42 with good correlations of R2 = 0.98 and 0.63, respectively. The negative sign of the ρ indicates that the more EDGs have higher impacts on stabilizing or reaching for the triplet ground states, displaying 4boldNHbold2 and 9boldNMebold2 as two silylenes with triplet ground states. The EWGs increase electrophilicity (ω) making 10boldNObold2 (7.62 eV) the most electrophilic. In contrast, EDGs increase nucleophilicity (N) showing 9boldNMebold2(5.03 eV) as the most nucleophilic silylene. Moreover, 9boldNMebold20.25emshows the highest proton affinity (PA = 388.13 kcal/mol), chemical potential (μ = −3.67 eV), energy of HOMO (EHOMO = −4.46 eV), dipole moment (5.44 debye), and the lowest band gap (ΔEH‐L = −1.59 eV), and electrophilicity (ω = 4.24 eV), with the lowest NBO charge on divalent Si atom (+0.129) among the scrutinized species.

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“…24,25 In those studies, rotational information up to J = 16, K a = 9 was obtained from the analysis of Doppler limited spectra. A combined fit with the previous visible 7,8 and infrared 17 absorption measurements was performed. TheX 1 A 1 state parameters were derived from the analysis of infrared diode laser spectroscopic measurements.…”

Section: Introductionmentioning

confidence: 99%

Detection and characterization of singly deuterated silylene, SiHD, via optical spectroscopy

Kokkin

Steimle

et al. 2016

The Journal of Chemical Physics

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Singly deuterated silylene has been detected and characterized in the gas-phase using high-resolution, two-dimensional, optical spectroscopy. Rotationally resolved lines in the 0 0 0X 1 A ′ →Ã 1 A ′′ band are assigned to both c-type perpendicular transition and additional parallel, axis-switching induced bands. The extracted rotational constants were combined with those for SiH 2 and SiD 2 to determine an improved equilibrium bond length, r SiH , and bond angle, θ, of 1.5137 ± 0.0003 Å and 92.04 • ± 0.05 • , and 1.4853 ± 0.0005 Å and 122.48 • ± 0.08 • for theX 1 A ′ (0, 0, 0) andÃ 1 A ′′ (0, 0, 0) state respectively. The dispersed fluorescence consists of a long progression in theÃ 1 A ′′ (0, 0, 0) →X 1 A ′ (0, ν 2 , 0) emission which was analyzed to produce vibrational parameters. A strong quantum level dependence of the rotationally resolved radiative decay curves is analyzed. Published by AIP Publishing. [http://dx

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Spectrum of SiH2

Cited by 112 publications

References 4 publications

Absorption spectroscopy of SiH2 near 640 nm

Absorption spectroscopy of SiH2 near 640 nm

Toward triplet disilavinylidenes: A Hammett electronic survey for substituent effects on singlet‐triplet energy gaps of silylenes by DFT

Detection and characterization of singly deuterated silylene, SiHD, via optical spectroscopy

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