Resonant two-photon ionization spectroscopy of jet-cooled RuC

Abstract

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 PdC

“…The important molecular orbitals are formed using the 4d Pd and 5s Pd orbitals of palladium and the 2s C and 2p C orbitals of carbon. As has been discussed in other papers from this group [13][14][15] and elsewhere, these orbitals combine to give low-lying 10, 11, and 5 orbitals. The 10 and 11 orbitals are somewhat difficult to characterize without detailed calculations, but the 10 orbital is probably mainly carbon 2s in character while the 11 orbital is probably a bonding orbital with significant contributions from the 4d Pd and 2p C orbitals.…”

Vibronic spectroscopy of unsaturated transition metal complexes: CrC2H, CrCH3, and NiCH3

“…1-7 A similarly large effort has been made to characterize diatomic transition metal oxides, nitrides, and carbides. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] In addition to these pure metallic clusters and diatomic molecules, a handful of more complicated polyatomic organometallic radicals involving open d-subshell transition metals have been investigated using gas phase spectroscopic methods. These include the transition metal methylidynes TiCH, 23 VCH, 24 NbCH, 25 TaCH, 26 and WCH, 27 the dicarbide YC 2 , 28,29 the acetylide YbCCH, 30 and the cyanides CuCN 31 and NiCN.…”

Spectroscopic constants and potential energy curves of yttrium carbide (YC)

“…The X 4 ⌺ − state has a considerably smaller dipole moment of 1.492 D, indicating a smaller charge transfer in comparison to other states of YC and also compared to other transition metal carbides. 11,12,[22][23][24]30,32 The A 4 ⌸ state is placed at 1661 cm −1 above the X 4 ⌺ − state with a vibrational frequency of 677 cm −1 ; this state has a much larger dipole moment of e = 4.377 D than the X 4 ⌺ − state. The relative energy separation of the X 4 ⌺ − state and the A 4 ⌸ state warrants additional discussion and is thus considered in Table III which shows the computed spectroscopic constants of the two states at various levels of theory.…”

“…Transition metal carbides such as RuC, FeC, MoC, RhC, PdC, NbC, TaC, WC, IrC, etc., [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]29 have been studied by theoretical techniques and some of these carbides have also been observed by high resolution spectroscopy. Among the second row diatomic transition metal carbides, YC appears to have received less attention compared to others in the period; hence the characterization of YC is by far less complete.…”