Rotational Spectrum of the AsH Radical in Itsa1Δ State, Studied by Far-Infrared Laser Magnetic Resonance

Hughes, Rebecca A.; Brown, John M.; Evenson, K. M.

doi:10.1006/jmsp.1997.7351

Cited by 4 publications

(1 citation statement)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compared to nitrogen and phosphorus-containing molecules, arsenic-bearing species have not attracted as much attention from spectroscopists. 1 In the field of pure rotational spectroscopy, for example, only a limited number of molecules have been characterized, such as AsF 3 , [2][3][4] AsCl 3 , 5 AsBr 3 , 6 AsH, 7 AsH 2 , 8,9 AsH 3 , 10,11 CH 3 CAs, 12 and AsP, 13 using far-infrared, millimeter-wave, or microwave techniques. However, due to a rising interest in functional materials made of As-doped carbon clusters, as well as the reactivity of arsenic ylides in organic synthesis, examining the basic properties of As-bearing compounds has acquired a renewed importance.…”

Section: Introductionmentioning

confidence: 99%

The Fourier transform microwave spectrum of the arsenic dicarbide radical (CCAs: X̃Π1∕22) and its C13 isotopologues

Sun

Clouthier

Ziurys

2009

The Journal of Chemical Physics

View full text Add to dashboard Cite

The pure rotational spectrum of the CCAs radical in its ground electronic and spin state, X (2)Pi(12), has been measured using Fourier transform microwave techniques in the frequency range of 12-40 GHz. This species was created in a supersonic expansion from a reaction mixture of AsCl(3) and C(2)H(2) or CH(4) diluted in high pressure argon, using a pulsed nozzle containing a dc discharge source. Three rotational transitions were measured for the main isotopologue, (12)C(12)CAs, in the Omega=12 ladder; both lambda-doubling and arsenic (I=32) hyperfine interactions were observed in these spectra. In addition, two to four rotational transitions were recorded for the (13)C(13)CAs, (13)C(12)CAs, and (12)C(13)CAs species. In these three isotopologues, hyperfine splittings were also resolved arising from the (13)C nuclei (I=12), creating complex spectral patterns. The CCAs spectra were analyzed with a case (a) Hamiltonian, and effective rotational, lambda-doubling, and arsenic and carbon-13 hyperfine constants were determined for the Omega=12 ladder. From the effective rotational constants of the four isotopologues, an r(m) ((1)) structure has been derived with r(C-C)=1.287 A and r(C-As)=1.745 A. These bond lengths indicate that the predominant structure for arsenic dicarbide is C=C=As, with some contributing C[Triple Bond]C and C[Triple Bond]As triple bond characters. The hyperfine constants established in this work indicate that about 23 of the unpaired electron density lies on the arsenic atom, with the remaining percentage on the terminal carbon. The value of the arsenic quadrupole coupling constant (eqQ=-202 MHz) suggests that the As-C bond has a mixture of covalent and ionic characters, consistent with theoretical predictions that both pi backbonding and electron transfer play a role in creating a linear, as opposed to a cyclic, structure for certain heteroatom dicarbides.

show abstract