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Title: Direct Experimental Probe of the On-Site Coulomb Repulsion in the Doubly Charged Fullerene Anion C702-

Abstract

Vibrationally resolved photoelectron spectra were obtained for cold C70- and C702-. Accurate values for the first and second electron affinities (EA’s) of C70 were measured as 2.765 ± 0.010 and eV, respectively, establishing that C702- is an electronically stable dianion in the gas phase. The difference between the first and second EA (2.745 eV) provides a direct experimental measure for the onsite coulomb and exchange interactions between the two excess electrons in C702-. Strong electron correlation effects were also observed between the two excess electrons in C702-.

Authors:
; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
882586
Report Number(s):
PNNL-SA-48377
3223; 8592; KP1303000
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters, 96(143002-1-4
Country of Publication:
United States
Language:
English
Subject:
Environmental Molecular Sciences Laboratory

Citation Formats

Wang, Xue B., Woo, Hin-koon, Huang, Xin, Kappes, Manfred M., and Wang, Lai S. Direct Experimental Probe of the On-Site Coulomb Repulsion in the Doubly Charged Fullerene Anion C702-. United States: N. p., 2006. Web. doi:10.1103/PhysRevLett.96.143002.
Wang, Xue B., Woo, Hin-koon, Huang, Xin, Kappes, Manfred M., & Wang, Lai S. Direct Experimental Probe of the On-Site Coulomb Repulsion in the Doubly Charged Fullerene Anion C702-. United States. doi:10.1103/PhysRevLett.96.143002.
Wang, Xue B., Woo, Hin-koon, Huang, Xin, Kappes, Manfred M., and Wang, Lai S. Thu . "Direct Experimental Probe of the On-Site Coulomb Repulsion in the Doubly Charged Fullerene Anion C702-". United States. doi:10.1103/PhysRevLett.96.143002.
@article{osti_882586,
title = {Direct Experimental Probe of the On-Site Coulomb Repulsion in the Doubly Charged Fullerene Anion C702-},
author = {Wang, Xue B. and Woo, Hin-koon and Huang, Xin and Kappes, Manfred M. and Wang, Lai S.},
abstractNote = {Vibrationally resolved photoelectron spectra were obtained for cold C70- and C702-. Accurate values for the first and second electron affinities (EA’s) of C70 were measured as 2.765 ± 0.010 and eV, respectively, establishing that C702- is an electronically stable dianion in the gas phase. The difference between the first and second EA (2.745 eV) provides a direct experimental measure for the onsite coulomb and exchange interactions between the two excess electrons in C702-. Strong electron correlation effects were also observed between the two excess electrons in C702-.},
doi = {10.1103/PhysRevLett.96.143002},
journal = {Physical Review Letters, 96(143002-1-4},
number = ,
volume = ,
place = {United States},
year = {Thu Apr 13 00:00:00 EDT 2006},
month = {Thu Apr 13 00:00:00 EDT 2006}
}
  • Photoelectron spectra of citric acid doubly charged anion were measured. The repulsive Coulomb barrier due to the two excess charges was directly probed and estimated to be about {approximately}1.9{endash} 2.5 eV . The adiabatic binding energy of the second electron was measured to be 1.0thinspthinspeV. Two detachment channels were observed, with the second channel at {approximately}0.6 eV higher in binding energy. The current study presents the first photodetachment experiments of a multiply charged anion and opens up new opportunities to study these novel molecular species. {copyright} {ital 1998} {ital The American Physical Society}
  • Photoelectron spectroscopy has been combined with an electrospray ionization technique to study gas-phase multiple charged anions and their intramolecular Coulomb repulsion and solvation stabilization. The authors report an initial study on a series of linear dicarboxylate dianions (DC{sup 2{minus}}), {sup {minus}}O{sub 2}C(CH{sub 2}){sub n}CO{sub 2}{sup {minus}} (n = 3--6), solvated by one and two waters. The second electron binding energy of DC{sup 2{minus}} decreases with decreasing aliphatic chain length owing to the increasing Coulomb repulsion between the two charges; the dianion with n = 2 has a binding energy close to zero and is not stable in the gas phase.more » The authors found that this dianion can be stabilized by one water, and in general the first water stabilizes the electron binding energy of DC{sup 2{minus}} by {approximately}0.3 eV. The second water, however, was observed to show a much stronger stabilization effect ({approximately}0.6 eV), suggesting that the two waters solvate the two carboxylate groups separately.« less
  • Photoelectron spectra of the three isomers of the benzene dicarboxylate dianion (o-, m-, and p-BDC{sup 2-}) were measured in the gas phase at five photon energies. Detachment features from the carboxylate groups and the {pi} electrons of the ring were clearly observed and distinguished. The electron binding energies were found to increase from the very small value of {approx}0.2 eV in o-BDC{sup 2-} to about 1.0 eV in p-BDC{sup 2-}, due to the reduced Coulomb repulsion as the two excess charges become farther apart. We found that the repulsive Coulomb barrier (RCB) for detaching electrons from the carboxylates decreases frommore » o-BDC{sup 2-} to p-BDC{sup 2-}. However, the RCB for detaching the ring {pi} electrons was found to be significantly higher and remain constant for the three isomers. This distinct anisotropy in the RCB involving different detachment channels is related to the different intramolecular Coulomb repulsions experienced by electrons localized on the carboxylates and the ring. Theoretical calculations were performed to obtain the equilibrium structures of both the dianions and the monoanions and to gain insight into the intramolecular electrostatic interactions. The two carboxylates in m- and p-BDC{sup 2-} were shown to be in-plane with the ring whereas the strong Coulomb repulsion in o-BDC{sup 2-} forces the carboxylate groups out of the plane of the ring. The theoretical results clearly show the localized nature of the excess charges on the carboxylates and help us understand the intramolecular Coulomb repulsions within the three dianions. (c) 2000 American Institute of Physics.« less
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