Electronic Structure of C ₆₀ (I ₂ ) _1.88 : a Photoemission Study

Abstract

Combined XPS and UPS data were obtained from stoichiometric iodine Cm crystals. The valence band spectra are diffuse although XAS data from the carbon K edge indicate little change in orbital energies upon doping. The C 1s core level (285.0 ev) does not show the expected downshift characteristic of an acceptor compound. The iodine 3d 6/2 level (620.1 ev) exhibits the same binding energy as in IC1 graphite indicating little ionicity. All spectra show significant shifts upon changing the temperature indicative of pronounced Fermi level pinning. The semiconducting nature also follows from the shape of the UPS data. All these data allow one to describe the compound as a Lewis-acid base adduct rather than an acceptor-type synthetic metal.

Electronic states of the DNA polynucleotides poly(dG)-poly(dC) in the presence of iodine

“…1͑b͒ and 1͑c͔͒. The observed BEs are identical to those for the iodine-doped C 60 system, 58 and thus the iodine in IGC-1 and IGC-2 is identified to be the I 3 − ion, which implies that the evaporated iodine acts as an electron acceptor and may create holes in poly͑dG͒-poly͑dC͒. 37 Figures 1͑d͒-1͑f͒ show N 1s core levels of NGC, IGC-1, and IGC-2.…”

Reversible Intercalation of Charged Iodine Chains into Carbon Nanotube Ropes

“…In contrast, C 60 readily forms charge-transfer solids with donors (K, Rb, Cs), but not acceptors [8,9]. None of these carbon polymorph solids have been observed so far to form a charge-transfer compound with iodine, which is a weak acceptor [8][9][10].…”

“…In contrast, C 60 readily forms charge-transfer solids with donors (K, Rb, Cs), but not acceptors [8,9]. None of these carbon polymorph solids have been observed so far to form a charge-transfer compound with iodine, which is a weak acceptor [8][9][10]. However, low-dimensional organic polymers, e.g., polyacetylene, have been intercalated with charged linear-chain polyiodides ͑I 3 ͒ 2 or ͑I 5 ͒ 2 [10][11][12].…”

Raman scattering and thermogravimetric analysis of iodine-doped multiwall carbon nanotubes

“…However, it is of interest to note that iodine can dope effectively into SWNTs, [5][6][7] whereas it can not intercalate into graphite 1 because of its large van der Waals diameter ͑0.396 nm͒ 8 and interatomic spacing ͑0.27 nm͒ incompatible with any spacing of the basal plane in graphite. 9,10 Raman scattering showed charged polyiodide ions to be distributed throughout the doped SWNTs bundles. 6 The images of atomic resolution Z-contrast scanning transmission electron microscopy 7 were taken for the doped nanotubes which protruded beyond the ends of the iodine-doped bundles, revealing the incorporation of iodine atoms in the form of helical chains inside the SWNT.…”