Calculated structures and microwave frequencies of HNSi and HSiN

Kroto, Harold W.; Murrell, J. N.; Al-Derzi, A. R.; Guest, Martyn F.

doi:10.1086/155851

Cited by 44 publications

(8 citation statements)

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“…As first predicted by Kroto et al [13], this constant is small and positive. Isovalent HNC also possesses a small, positive eQq(N) [0.2641(10) MHz; Ref.…”

Section: Isotopic Hnsisupporting

confidence: 77%

“…Many electronic structure calculations [11][12][13][14][15][16][17][18] have been carried out on the HSiN-HNSi potential energy surface, the latest and most comprehensive being that of Lind et al [1]. In that study, relative energies, barrier heights to isomerisation, optimised geometries, dipole moments, vibrational frequencies which include anharmonic corrections, vibrational isotopic shifts, and dissociation energies were calculated for both isomers by a variety of highly correlated ab initio quantum chemical methods.…”

Section: Introductionmentioning

confidence: 99%

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High-resolution rotational spectroscopy of iminosilylene, HNSi

2015

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By means of Fourier transform microwave spectroscopy of a supersonic beam, the fundamental rotational transition of isotopic and vibrationally excited iminosilylene, HNSi, has been detected. In addition to seven isotopic species, vibrational satellite transitions from more than 30 vibrationally excited states, including the three fundamental modes, have been detected. Those from ν 2 are particularly intense, enabling detection of transitions from as high as (0,22 0 ,0) (i.e. ∼10,000 cm −1 above ground). At high spectral resolution, well-resolved nitrogen quadrupole structure has been observed in nearly every transition. Excitation of ν 1 or ν 3 changes eQq(N) little, but eQq(N) systematically decreases with increasing excitation of the ν 2 bend, from a value of 0.376(5) MHz for (0,0 0 ,0) to −2.257(5) MHz for (0,20 0 ,0). With the large amount of new data in hand, it has also been possible to determine the leading vibration-rotation constants (α i and γ i ) for ν 2 or ν 3 to high precision, and derive a revised semi-empirical equilibrium structure for this fundamental triatomic molecule. Various electronic and molecular properties of iminosilylene have been calculated at the coupled cluster level of theory, and these generally agree well with experiment and previous calculations. An unsuccessful search for HSiN, a highly polar isomer calculated to lie nearly 3 eV above HNSi, is also reported.

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“…As first predicted by Kroto et al [13], this constant is small and positive. Isovalent HNC also possesses a small, positive eQq(N) [0.2641(10) MHz; Ref.…”

Section: Isotopic Hnsisupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

High-resolution rotational spectroscopy of iminosilylene, HNSi

2015

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“…structure of formaldehyde, H2C=0, has already been calculated with a variety of basis sets.144,36'38'39 '98 The 3-21G C-O bond distance of 1.207 A is only 0.004 Á longer than the experimental value of 1.203 Á. 97 The 3-21G H-C-O bond angle, 122.5°, is slightly larger than experiment, 121.75°. 98 The triplet (3A") state of formaldehyde is calculated to be 74.2 kcal/mol above the 'A!…”

Section: •58mentioning

confidence: 97%

A theoretical survey of unsaturated or multiply bonded and divalent silicon compounds. Comparison with carbon analogs

Luke¹,

Pople²,

et al. 1986

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“…Among the compounds having multiple bonds to silicon [24] one of the most attractive is HNSi, the silicated counterpart of HNC, which is suspected to be present in dense interstellar clouds [1][2][3][4][5][6][7]. Numerous studies, experimental and theoretical, have been devoted to this species for many decades [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42].…”

Section: Hnsimentioning

confidence: 99%

Interstellar silicon-nitrogen chemistry. I. The microwave and the infrared signatures of the HSiN, HNSi, HSiNH2, HNSiH2 and HSiNH+ species

Parisel¹,

Hanus²,

Ellinger³

1996

Chemical Physics

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The experimental and the theoretical interests for the silicon chemistry have been renewed by the recent detection of SiN in space. In this contribution a theoretical study of the HSiN, HNSi, HSiNH 2 and HNSiH 2 molecular systems is presented that aims to help in the interpretation of available experimental results as well as in the attribution of new interstellar lines. The main goal of this report remains, however, the calibration of ab initio calculations on still-unknown silicon-nitrogen systems: the infrared and the microwave signatures of the HSiNH + cation are reported as a direct application. The signatures of the five molecules under investigation have been computed a t increasing levels of post-Hartree-Fock theories, using up to a 6-311 +-t-G * * atomic orbital expansion. Accurate geometries and B e rotational constants have been determined at the M~511er-Plesset MPn (n = 2, 3, 4), CASSCF and CCSD(T) theoretical plateaus for HNSi. The comparison with experimental data allows then to derive the scaling factors needed to obtain accurate rotational constants for related species: they are applied as such on the crude constants determined for HSiN, HSiNH 2, HNSiH 2, and finally HSiNH 2 in its floppy linear singlet ground state and in its lowest cis-bent a3p(state as well. Dipole moments are reported in order to assess the feasability for these species to be detected owing to their rotational signatures either in the laboratory or in space using millimetric radioastronomy techniques. Infrared (IR) signatures are computed at the same levels of theory and compared to the recent matrix isolation experiments devoted to HSiN, HNSi, HSiNH 2 and HNSiH 2. The calculations unambiguously confirm that all these species have been effectively produced and observed. They also lead to the determination of accurate IR scaling factors that are significantly larger than the usual ones. Such an approach allows then to quantitatively predict the IR spectra of the still-unknown HSiNH ÷ entity. The study of the IR spectra furthermore points out the failure of single-reference correlation methods to obtain predictive IR signatures in some cases, as is unambiguously illustrated in the case of the HSiN species.

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Calculated structures and microwave frequencies of HNSi and HSiN

Cited by 44 publications

References 0 publications

High-resolution rotational spectroscopy of iminosilylene, HNSi

High-resolution rotational spectroscopy of iminosilylene, HNSi

A theoretical survey of unsaturated or multiply bonded and divalent silicon compounds. Comparison with carbon analogs

Interstellar silicon-nitrogen chemistry. I. The microwave and the infrared signatures of the HSiN, HNSi, HSiNH2, HNSiH2 and HSiNH+ species

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