Optical spectroscopy of tungsten carbide (WC)

Sickafoose, Shane M.; Smith, Adam W.; Morse, Michael D.

doi:10.1063/1.1427068

Cited by 46 publications

(35 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Note that the proposed configuration 9 for the [17.6]2 state of ..14σ 2 8π 3 15σ 2 4δ(5d)16σ 2 (6s) is consistent with the observed reduction of μ upon excitation because the highly polarizable 16σ orbital is doubly occupied. This configuration is also consistent with the observed negligible hyperfine splitting in the [17.6]2 state.…”

supporting

confidence: 66%

“…Previous high-resolution spectroscopic studies of WC are limited to the mass selected resonance enhanced multiphoton ionization spectrum (REMPI), and the dispersed laser induced fluorescence study performed by the Morse group. 9 In that study numerous bands in the 17 500 cm −1 to 24 000 cm −1 spectral region were observed, many of which were assigned to progressions in the [17.6]2-X The supersonic molecular beam apparatus and laser induced fluorescence (LIF) optical detection scheme for the Stark measurements was identical to that recently used in the study of ThO. 12 A tungsten rod was ablated with the ∼2 mJ of 532 nm radiation.…”

mentioning

confidence: 99%

“…9 The doubling of the 183 WC spectral features is caused by 183 W(I = 1/2) magnetic hyperfine interaction. The transition frequencies for the R (1-3), Q (2)(3)(4)(5)(6), and P(3-4) lines of the four isotopologues were precisely measured and are available via the supplementary material.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Communication: Electric dipole moment and hyperfine interaction of tungsten monocarbide, WC

Wang

Steimle

2011

The Journal of Chemical Physics

View full text Add to dashboard Cite

The [17.6]2← X3Δ1(1,0) band of tungsten monocarbide, WC, was recorded using laser induced fluorescence both field-free and in the presence of a static electric field. The Stark induced shifts of the R(1) and Q(2) lines were analyzed to produce values for the permanent electric dipole moments, μ, of 3.90 ± 0.04 D and 2.57 ± 0.04 D for the X3Δ1(v = 0) and [17.6]2(v = 1) states, respectively. An upper limit to the Ω-doubling parameter, $\tilde o_\Delta$õΔ, of 2 MHz is established. The 183W(I = 1/2) Fermi contact parameter, bF, for the X3Δ1(v = 0) is estimated to be 1363 MHz. The results are compared with theoretical predictions and a molecular orbital correlation description.

show abstract

supporting

confidence: 66%

mentioning

confidence: 99%

See 1 more Smart Citation

Communication: Electric dipole moment and hyperfine interaction of tungsten monocarbide, WC

Wang

Steimle

2011

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…3 are the only other experimental observation of the 2 S 1∕2 excited state. The WC neutral ground state has been previously identified by optical (20) and anion photoelectron (21) spectroscopic methods to be the triplet 3 Δ 1 ( ½… 4δ 1 16σ 1 ). This electronic term designation and orbital occupation are analogous to the lowest energy triplet 3 D 3 ( ½Xe 5d 9 6s 1 ) level of the neutral isoelectronic element, Pt (apart from the Ω∕J inversion).…”

Section: Resultsmentioning

confidence: 99%

Superatom spectroscopy and the electronic state correlation between elements and isoelectronic molecular counterparts

Peppernick

Gunaratne²,

Castleman

2009

Proc. Natl. Acad. Sci. U.S.A.

101

View full text Add to dashboard Cite

Detailed in the present investigation are results pertaining to the photoelectron spectroscopy of negatively charged atomic ions and their isoelectronic molecular counterparts. Experiments utilizing the photoelectron imaging technique are performed on the negative ions of the group 10 noble metal block (i.e. Ni − , Pd − , and Pt − ) of the periodic table at a photon energy of 2.33 eV (532 nm). The accessible electronic transitions, term energies, and orbital angular momentum components of the bound electronic states in the atom are then compared with photoelectron images collected for isoelectronic early transition metal heterogeneous diatomic molecules, M-X − (M ¼ Ti; Zr; W; X ¼ O or C). A superposition principle connecting the spectroscopy between the atomic and molecular species is observed, wherein the electronic structure of the diatomic is observed to mimic that present in the isoelectronic atom. The molecular ions studied in this work, TiO − , ZrO − , and WC − can then be interpreted as possessing superatomic electronic structures reminiscent of the isoelectronic elements appearing on the periodic table, thereby quantifying the superatom concept.cluster anions | photoelectron imaging | superatoms | angular distributions | transition metal A lchemy, the medieval practice that endeavored to transform mundane elements into the rarer, exotic variety has found many analogies in the modern physical sciences ranging from gas-phase clusters (1) to surface science (2). Particularly intriguing was a report (2) demonstrating that a tungsten carbide surface displayed similar chemical reactivity as the noble metal platinum, an element well established in its propensity for catalytically initiating a vast array of chemical transformations. By contrast, elemental tungsten alone did not exhibit comparable reactivity patterns. In order to provide insight to these findings, we have undertaken a comparative spectroscopic investigation between anionic group 10 elements ðNi − ; Pd − ; Pt − Þ and their complementary isoelectronic early transition metal molecular counterparts M-X − (M ¼ Ti; Zr; W and X ¼ O or C). We observe photoelectron signatures and angular distributions in the acquired images that exhibit very similar aspects between the respective atom and molecule. This observation suggests a correlation between the spectroscopy of an element and the isoelectronic molecular species. As a representative example, consider the formation of the diatomic molecule TiO from the united atom perceptive of molecular orbital theory (3). If only the 6 valence electrons of O ( ½He 2s 2 2p 4 ) are to be considered, subsequent combination with the 4 valence electrons of Ti ( ½Ar 3d 2 4s 2 ) creates a molecular entity with an isoelectronic configuration commensurate with the 10 valence electrons of elemental Ni ( ½Ar 3d 8 4s 2 ). In other words, the early transition metal Ti is positioned on the periodic table 6 elements removed from Ni and the intervening periodic span is traversed by the valency of atomic O. The diatomic molecule, TiO,...

show abstract

“…With the much lower temperature the 4 P i assignment of the ground state was unambiguous, and led to the interesting result that the carbon 2p molecular orbitals lie at almost the same energy as the metal 5s. Since then a number of monocarbides have been found, most notably FeC [12,13], CoC [14,15], NiC [16], NbC [17], MoC [18], PdC [19], and WC [20].…”

Section: Introductionmentioning

confidence: 99%