FeC[sub [ital n]][sup [minus]] and FeC[sub [ital n]]H[sup [minus]] ([ital n]=3,4): A photoelectron spectroscopic and density functional study

Journal Article · Wed Feb 15 04:00:00 EST 1995 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.468646· OSTI ID:6865816

Fan, J ^[1]; Lou, L ^[2]; Wang, L ^[3]

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1. Environmental Molecular Sciences Laboratory, Pacific Northwest Laboratory, MS K2-14, Richland, Washington 99352 (United States)
2. Rice Quantum Institute and Departments of Chemistry and Physics, Rice University, Houston, Texas 77251 (United States)
3. Environmental Molecular Sciences Laboratory, Pacific Northwest Laboratory, MS K2-14, Richland, Washington 99352 (United States) Department of Physics, Washington State University, Richland, Washington 99352 (United States)

Photoelectron spectra of the title molecules are reported at 3.49 eV photon energy. Vibrational structures are resolved in the spectra of FeC[sup [minus]][sub 3] and FeC[sub 3]H[sup [minus]]. The FeC[sup [minus]][sub 4] spectrum is unusually broad, indicating a large equilibrium geometry change from the anion to the neutral states. The FeC[sub 4]H[sup [minus]] spectrum exhibits a single strong feature. Theoretical studies using the density functional theory are carried out to determine the structures and bonding of these clusters. All the molecules in the anion ground states are found to be linear with the Fe atom bonded at one end. The Fe and C bonding involves strong Fe 4[ital s] and C [ital sp] interactions as well as considerable Fe 3[ital d] and C [pi] interactions. The [ital n]=3 species can be best characterized by cumulenic types of bonding with FeC[sub 3]H also having an acetylenic isomer. The [ital n]=4 species in the linear structures can be approximately described by diacetylenic types of bonding. Mulliken charge analyses indicate that the extra charge in all the anions enters mainly into the Fe 4[ital s] antibonding orbital, in agreement with the assignment that the threshold detachment takes place from the [sigma]* orbital mainly between the Fe and C atoms. The vibrational structure resolved in the FeC[sup [minus]][sub 3] spectrum yields a Fe--C stretching frequency of 700 (150) cm[sup [minus]1] for the first excited state of FeC[sub 3], in agreement with the Fe--C multiple bonding character.

• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6865816
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 102:7; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

664100 -- Theory of Electronic Structure of Atoms & Molecules-- (1992-)
664200* -- Spectra of Atoms & Molecules & their Interactions with Photons-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ANIONS
CARBIDES
CARBON COMPOUNDS
CHARGED PARTICLES
CHEMICAL BONDS
ELECTRON SPECTROSCOPY
ENERGY LEVELS
EQUILIBRIUM
EXCITED STATES
GEOMETRY
GROUND STATES
HYDRIDES
HYDROGEN COMPOUNDS
ION PAIRS
IONS
IRON CARBIDES
IRON COMPOUNDS
IRON HYDRIDES
MATHEMATICS
PHOTOELECTRON SPECTROSCOPY
RESOLUTION
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
VIBRATIONAL STATES