Origins of structure in the e1 ionisation bands of magnesocene and osmocene. A photoelectron spectroscopic study of M(η−C5D5)2, MMg and Os

Bähr, Anja; Cooper, Glyn; Green, Jennifer C.; Longley, Katherine A.; Lovell-Smith, Marcus; McGrady, G. Sean

doi:10.1016/0301-0104(95)00365-7

Cited by 6 publications

(3 citation statements)

References 25 publications

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“…The drop in the band area is not as great as expected for pure chlorine p orbital character indicating that the chloride ligand is mixing substantially with the metal. Bands five and six have similar positions, areas, and splitting to the Cp e 1 "-based ionizations seen in previously studied piano-stool compounds [56,57] and are assigned as Cp ionizations. The last band is assigned to the Ru-Cl σ ionization (σ) based on the position and band area decrease in going from He I to He II radiation, consistent with FpCl and other metal chlorides [47,58].…”

Section: Rpcl Ionizationssupporting

confidence: 64%

Experimental measure of metal–alkynyl electronic structure interactions by photoelectron spectroscopy: (η5-C5H5)Ru(CO)2C CMe and [(η5-C5H5)Ru(CO)2]2(μ-C C)

et al. 2015

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The gas-phase He I and He II photoelectron spectra of the propynylruthenium molecule CpRu(CO) 2 C≡CMe (Cp = η 5-C 5 H 5) and the ethynediyldiruthenium molecule [CpRu(CO) 2 ] 2 (µ-C≡C) are compared with the spectrum of CpRu(CO) 2 Cl to experimentally determine electronic structure interactions of the alkynyl ligands with the metal. The spectra indicate that the interaction between the filled metal-dπ and filled alkynyl-π orbitals dominates the metal-alkynyl π electronic structure, mirroring previously characterized CpFe(CO) 2 alkynyls. All valence ionizations of the Ru molecules are stabilized with respect to similar Fe compounds, contrary to the common expectation of lower ionization energies with atomic substitution down a column of the periodic table. Ab initio electronic structure calculations suggest that this stabilization traces to the greater inherent electronic relaxation energy associated with removal of Fe 3d electrons compared to removal of Ru 4d electrons. Destabilization of the first two ionization bands of the diruthenium molecule are a result of filled-filled interactions between alkynyl π-bonds with the symmetric combination of metal-metal-dπ orbitals, showing electronic communication between the metals through the alkynyl bridge. From the photoelectron spectrum, this communication was calculated to have a minimum electron-transfer integral of 0.56 eV. The stabilization of the antisymmetric combination of the metal-metal-dπ orbitals gives a direct and unique experimental measure of the interaction with the alkynyl π* orbitals. The stabilization caused by the alkynyl π* orbitals was found to be approximately one-third of the destabilization caused by the filled-filled interaction with the alkynyl π-bonds and about one-fourth to one-third the stabilization provided by back-bonding to a carbonyl ligand.

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Section: Rpcl Ionizationssupporting

confidence: 64%

Experimental measure of metal–alkynyl electronic structure interactions by photoelectron spectroscopy: (η5-C5H5)Ru(CO)2C CMe and [(η5-C5H5)Ru(CO)2]2(μ-C C)

et al. 2015

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“…The most probable origin of the SO splitting comes from small contri-butions from the Re 5p and 6p orbitals. Similar splittings in PE bands in the spectra of OsO 4 37 and Os(η-C 5 H 5 ) 2 38 have been shown to originate in a combination of core and valence p contributions to the associated orbitals. The higher M-C ionisation bands, from 8a 1 and 4b 1 , may be associated with the shoulders perceptible on the low IE edge of the main band in the He I spectrum.…”

Section: Electronic Structure Ofmentioning

confidence: 57%

Structural studies and matrix photochemistry of tetramethyloxorhenium(vi), (CH3)4ReO, and related compounds

Morris

Downs

Green

et al. 2002

J. Chem. Soc., Dalton Trans.

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“…Depending on the energy of the vibrational mode and the stabilization energy provided by distortion of the geometry, the Jahn−Teller effect can be either static or dynamic . If the energy of a Cp vibrational mode is comparable to the stabilization energy provided by Cp ring distortion, strong vibronic coupling can occur …”

Section: Resultsmentioning

confidence: 99%

Electronic Structure of Early Transition-Metal Carbonyls: Gas-Phase Photoelectron Spectroscopy of (η⁵-C₅H₅)M(CO)₄ (M = V, Nb, Ta)

et al. 2000

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Gas-phase photoelectron spectroscopy is used to investigate the bonding between early transition metals and carbonyl and cyclopentadienyl ligands for the molecules (η 5 The lowest ionization energy region contains two overlapping ionizations that arise from the two orbitals that are occupied according to the formal d 4 metal configuration. However, the character of these ionizations is dominated by the carbonyls rather than by the metals, as evidenced by the extensive C-O stretching vibrational progressions observed with these ionizations, by the trends in the ionization cross sections between the molecules and with different ionization sources, and by the relative lack of shifts of these ionizations with metal substitution from vanadium to niobium to tantalum or with trimethylsilyl and acetyl substitutions on the cyclopentadienyl. The second group of ionizations for these molecules corresponds to orbitals with predominantly cyclopentadienyl π character that donate to empty metal d orbitals. A much larger shift of these ionizations is observed upon cyclopentadienyl substitution. The molecular structures are sensitive to the electron configurations. Both density functional theory and ab initio calculations reproduce well the geometry of the neutral molecules and also predict the geometry changes upon ionization. The first ionization, which relates to an orbital with the a 1 symmetry of the metal d z 2 orbital, is broad due to a substantial geometry change upon removal of an electron from this orbital. The shoulder on the cyclopentadienylbased ionizations relates to a dynamic Jahn-Teller geometrical distortion. The unusually large metal-to-carbonyl back-bonding observed in these molecules is facilitated by the interligand overlap between the four carbonyls, which substantially stabilizes the appropriate symmetry-adapted carbonyl π* acceptor orbitals. The extensive carbonyl character in the valence electronic structure diminishes any trends in properties with substitutions of the metals down the group or with substitutions on the cyclopentadienyl ring.

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Origins of structure in the e1 ionisation bands of magnesocene and osmocene. A photoelectron spectroscopic study of M(η−C5D5)2, MMg and Os

Cited by 6 publications

References 25 publications

Experimental measure of metal–alkynyl electronic structure interactions by photoelectron spectroscopy: (η5-C5H5)Ru(CO)2C CMe and [(η5-C5H5)Ru(CO)2]2(μ-C C)

Experimental measure of metal–alkynyl electronic structure interactions by photoelectron spectroscopy: (η5-C5H5)Ru(CO)2C CMe and [(η5-C5H5)Ru(CO)2]2(μ-C C)

Structural studies and matrix photochemistry of tetramethyloxorhenium(vi), (CH3)4ReO, and related compounds

Electronic Structure of Early Transition-Metal Carbonyls: Gas-Phase Photoelectron Spectroscopy of (η⁵-C₅H₅)M(CO)₄ (M = V, Nb, Ta)

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Origins of structure in the e1 ionisation bands of magnesocene and osmocene. A photoelectron spectroscopic study of M(η−C5D5)2, MMg and Os

Cited by 6 publications

References 25 publications

Experimental measure of metal–alkynyl electronic structure interactions by photoelectron spectroscopy: (η5-C5H5)Ru(CO)2C CMe and [(η5-C5H5)Ru(CO)2]2(μ-C C)

Experimental measure of metal–alkynyl electronic structure interactions by photoelectron spectroscopy: (η5-C5H5)Ru(CO)2C CMe and [(η5-C5H5)Ru(CO)2]2(μ-C C)

Structural studies and matrix photochemistry of tetramethyloxorhenium(vi), (CH3)4ReO, and related compounds

Electronic Structure of Early Transition-Metal Carbonyls: Gas-Phase Photoelectron Spectroscopy of (η5-C5H5)M(CO)4 (M = V, Nb, Ta)

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Electronic Structure of Early Transition-Metal Carbonyls: Gas-Phase Photoelectron Spectroscopy of (η⁵-C₅H₅)M(CO)₄ (M = V, Nb, Ta)