A resonant two-photon ionization study of the jet-cooled RuC molecule has identified the ground state as a Σ+1 state arising from the 10σ211σ25π42δ4 configuration. The Δi3 state arising from the 10σ211σ25π42δ312σ1 configuration lies very low in energy, with the Δ33 and Δ23 components lying only 76 and 850 cm−1 above the ground state, respectively. Transitions from the X 1Σ+, Δ33, and Δ23 states to the Π23, Π13, Φ33, Φ43, Φ31, and Π11 states arising from the 10σ211σ25π42δ36π1 configuration have been observed in the 12 700–18 100 cm−1 range, allowing all of these states to be placed on a common energy scale. The bond length increases as the molecule is electronically excited, from r0=1.608 Å in the 2δ4, X 1Σ+ state, to 1.635 Å in the 2δ312σ1, Δ3 state, to 1.66 Å in the 2δ36π1, Π3 and Φ3 states, to 1.667 Å in the 2δ36π1, Φ1 and 1.678 Å in the 2δ36π1, Π1 state. A related decrease in vibrational frequency with electronic excitation is also observed. Hyperfine splitting is observed in the 2δ312σ1, Δ33 state for the Ru99(I=5/2)12C and Ru101(I=5/2)12C isotopic combinations. This is analyzed using known atomic hyperfine parameters to show that the 12σ orbital is roughly 83% 5sRu in character, a result in good agreement with previous work on the related RhC and CoC molecules.

Resonant two-photon ionization spectroscopy of jet-cooled tantalum carbide, TaCThe first optical investigation of the spectra of diatomic PdC has revealed that the ground state has ⍀ϭ0 ϩ , with a bond length of r 0 ϭ1.712 Å. The Hund's case ͑a͒ nature of this state could not be unambiguously determined from the experimental data, but dispersed fluorescence studies to be reported in a separate publication, in combination with a comparison to theoretical calculations, demonstrate that it is the 2␦ 4 12 2 , 1 ⌺ 0 ϩ ϩ state, which undergoes spin-orbit mixing with a low-lying 2␦ 4 12 1 6 1 , 3 ⌸ 0 ϩ state. An excited 3 ⌺ ϩ state with r e ϭ1.754Ϯ0.003 Å (r 0 ϭ1.758 Ϯ0.002 Å) and ⌬G 1/2 ϭ794 cm Ϫ1 is found at T 0 ϭ17 867 cm Ϫ1 . Although only the ⍀ϭ1 component of this state is directly observed, the large hyperfine splitting of this state for the 105 Pd 12 C isotopomer implies that an unpaired electron occupies an orbital that is primarily of 5s character on Pd. Comparison to ab initio calculations identifies this state as 2␦ 4 12 1 13 1 , 3 ⌺ 1 ϩ . To higher wavenumbers a number of transitions to states with ⍀ϭ0 ϩ have been observed and rotationally analyzed. Two groups of these have been organized into band systems, despite the clear presence of homogeneous perturbations between states with ⍀ϭ0 ϩ in the region between 22 000 and 26 000 cm Ϫ1 .

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Jet-cooled diatomic PtSi, produced in a laser ablation supersonic expansion source, has been spectroscopically investigated between 17 400 and 24 000 cm−1 by resonant two-photon ionization spectroscopy. Two vibrational progressions are observed and identified as the [15.7]Ω′=1←X 1Σ+ and [18.5]Ω′=1←X 1Σ+ band systems. Three bands in the former system and six bands in the latter system were rotationally resolved and analyzed, leading to bond lengths of re′=2.1905(13) Å and re′=2.2354(3) Å for the [15.7]Ω′=1 and [18.5]Ω′=1 states, respectively. The Ω″=0 ground state of PtSi is assigned as a 1Σ+ state, in agreement with previous work and with the assigned ground states of the isovalent NiC, PdC, PtC, and NiSi molecules. The ground state bond length of PtSi is given by r0″=2.0629(2) Å. A Rydberg–Klein–Rees analysis of the ground and excited state potential energy curves is presented, along with a discussion of the chemical bonding and a comparison to the isoelectronic molecule, AlAu. Evidence is presented for a double bond in PtSi, as opposed to a single bond in AlAu.

Oil derived from vacuum pyrolysis of waste rubber tires was used as a coal liquefaction solvent with a high-volatile A bituminous coal and a Mo catalyst. The vacuum-pyrolyzed tire oil along with the Mo catalyst was found to convert over 90% (daf) of the coal to gas, oil, and asphaltenes. Reactions were carried out in tubing reactors heated to 430 °C under 1000 psig (cold) of hydrogen gas. The vacuum-pyrolyzed tire oil (PTO) obtained from waste rubber tires contained various polyaromatic molecules which have been shown to be beneficial in coal liquefaction. Coal conversion was found to be hydrogen pressure dependent for reactions where coal and PTO were coprocessed together. Conversion results show that most of the coal reacted within the first 10 min of coprocessing. Electron probe microanalysis (EPMA) detected the presence of Mo inside coal particles after 20 min of coprocessing coal and PTO.