The observation of the gaseous UFO(-) anion is reported, which is investigated using photoelectron spectroscopy and relativisitic ab initio calculations. Two strong photoelectron bands are observed at low binding energies due to electron detachment from the U-7sσ orbital. Numerous weak detachment bands are also observed due to the strongly correlated U-5f electrons. The electron affinity of UFO...

Zwitterions are critically important in many biological transformations and are used in numerous chemical processes. The consequences of electrostatic effects on reactivity and physical properties, however, are largely unknown. In this work, we report the results of negative ion photoelectron spectra of nine isomeric pyridinium dicarboxylate zwitterions and three nonzwitterionic methoxycarbonyl...

Previously determined experimental data for thermal attachment of electrons to SF(6) and thermal detachment from SF(6)(-) over the range 590-670 K are reevaluated by a third-law analysis. Recent high precision calculations of SF(6)(-) harmonic frequences and anharmonicities (for several of the modes) lead to considerable changes in modeled vibrational partition functions which then have to be a...

Iron-pyrene cluster anions, [Fe(m)(pyrene)(n)](-) (m = 1-2, n = 1-2) were studied in the gas phase by photoelectron spectroscopy, resulting in the determination of their electron affinity and vertical detachment energy values. Density functional theory calculations were also conducted, providing the structures and spin multiplicities of the neutral clusters and their anions as well as their res...

A photodetachment photoelectron spectroscopy study of a doubly charged anion (S2O8 ) in the gas phase is reported at three photon energies: 193, 266, 355 nm. Adiabatic and vertical electron binding energies of S2O8 22 were measured to be 1.760.2 and 2.260.1 eV, respectively. Several excited states were observed for the S2O8 2 singly charged anion at 193 nm. The repulsive Coulomb barrier that bi...

The 364 nm negative ion photoelectron spectrum of WO2 is obtained. The spectrum reveals that four different electronic states are accessed in the neutral molecule following electron detachment. From the rich vibrational structure the vibrational frequencies of the bending and/or symmetric stretching vibrations are measured. The electron affinity is determined to be 1.998(10) 0.040k eV, where k ...

The chemical structure and bonding of Al4C and Al4C have been studied by photoelectron spectroscopy and ab initio calculations. While Al4C is known to be a tetrahedral molecule, the data reported here suggest that Al4C has D4h symmetry (when averaged over zero-point vibrational motions) and thus is the smallest species identified to date that contains a tetracoordinated planar carbon atom. The ...

High-resolution photoelectron imaging and spectroscopy of cold C₆₀⁻ anions are reported using a newly built photoelectron imaging apparatus coupled with an electrospray ionization source and a temperature-controlled cryogenic ion trap. Vibrationally resolved photoelectron spectra are obtained for the detachment transition from the ground state of C₆₀⁻ to that of C60 at various detachment wavele...

† Managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. Abstract Investigations have been conducted to determine the feasibility of using collisional cooling for reducing the energy spreads and, consequently, the emittances of negative-ion beams. We have designed a gas-filled RFquadrupole ion cooler equipped with provisions for retarding energetic nega...

The adult mammalian retinal pigment epithelium (RPE) is mitotically inactive, yet retains the capacity to proliferate under certain conditions. To determine the onset of RPE proliferation after retinal detachment, we examined experimentally detached cat retinas of 12, 24, 48, and 72 hr duration. An additional animal served as a nondetached, sham-operated control. 3H-thymidine was injected into ...