The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
John M. Dyke - One of the best experts on this subject based on the ideXlab platform.
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The X̃ 2B1, 2B2, 2A1, and 2A2 states of Oxygen Difluoride cation (F2O+): High-level ab initio calculations and simulation of the ultraviolet photoelectron spectrum of F2O
The Journal of Chemical Physics, 2001Co-Authors: De-chao Wang, Foo-tim Chau, Daniel K. W. Mok, Edmond P. F. Lee, Levi Beeching, J. Steven Ogden, John M. DykeAbstract:The ultraviolet photoelectron spectrum of F2O was recorded with a higher resolution than previously published. New vibrational structure was observed in the second and third bands. Near state-of-the-art molecular orbital calculations were performed on the X 1A1 state of F2O and the X 2B1, 2B2, 2A1, and 2A2 state of F2O+, and their potential energy functions were computed. Spectral simulations based on Franck–Condon factor calculations including the Duchinsky effect were carried out within the harmonic oscillator model and also with the inclusion of anharmonicity, in order to assist spectral assignment. Based on the computed ionization energies obtained with the coupled cluster and multireference configuration interaction methods with basis sets of up to quintuple zeta quality, the order of the low-lying cationic states of F2O+ has been firmly established. However, the detailed assignment of the overlapping second and third photoelectron bands was only achieved with the aid of spectral simulation. The it...
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the x 2b1 2b2 2a1 and 2a2 states of Oxygen Difluoride cation f2o high level ab initio calculations and simulation of the ultraviolet photoelectron spectrum of f2o
Journal of Chemical Physics, 2001Co-Authors: De-chao Wang, Foo-tim Chau, Daniel K. W. Mok, Edmond P. F. Lee, Levi Beeching, Steven J Ogden, John M. DykeAbstract:The ultraviolet photoelectron spectrum of F2O was recorded with a higher resolution than previously published. New vibrational structure was observed in the second and third bands. Near state-of-the-art molecular orbital calculations were performed on the X 1A1 state of F2O and the X 2B1, 2B2, 2A1, and 2A2 state of F2O+, and their potential energy functions were computed. Spectral simulations based on Franck–Condon factor calculations including the Duchinsky effect were carried out within the harmonic oscillator model and also with the inclusion of anharmonicity, in order to assist spectral assignment. Based on the computed ionization energies obtained with the coupled cluster and multireference configuration interaction methods with basis sets of up to quintuple zeta quality, the order of the low-lying cationic states of F2O+ has been firmly established. However, the detailed assignment of the overlapping second and third photoelectron bands was only achieved with the aid of spectral simulation. The it...
Lester Andrews - One of the best experts on this subject based on the ideXlab platform.
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reactions of lanthanide atoms with Oxygen Difluoride and the role of the ln oxidation state
ChemInform, 2014Co-Authors: Tanya Mikulas, Mingyang Chen, Kirk A Peterson, Yu Gong, David A. Dixon, Lester AndrewsAbstract:Oxidative addition products OLnF2 (Ln: lanthanide) and OLnF are obtained by condensation of laser-ablated Ln atoms with OF2 in excess argon or neon at 4 K.
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reactions of lanthanide atoms with Oxygen Difluoride and the role of the ln oxidation state
Inorganic Chemistry, 2014Co-Authors: Tanya Mikulas, Mingyang Chen, Kirk A Peterson, Yu Gong, David A. Dixon, Lester AndrewsAbstract:Laser-ablated lanthanide metal atoms were condensed with OF2 in excess argon or neon at 4 K. New infrared absorption bands were observed and assigned to the oxidative addition products OLnF2 and OL...
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Reactions of Lanthanide Atoms with Oxygen Difluoride and the Role of the Ln Oxidation State
Inorganic Chemistry, 2013Co-Authors: Tanya Mikulas, Mingyang Chen, Kirk A Peterson, Yu Gong, David A. Dixon, Lester AndrewsAbstract:Laser-ablated lanthanide metal atoms were condensed with OF2 in excess argon or neon at 4 K. New infrared absorption bands were observed and assigned to the oxidative addition products OLnF2 and OLnF on the basis of 18O isotopic substitution and electronic structure calculations of the vibrational frequencies. The dominant absorptions in the 500 cm–1 region are identified as Ln–F stretching modes, which follow the lanthanide contraction. The Ln–O stretching frequency is an important measure of the oxidation states of the Ln and Oxygen and the spin state of the complex. The OCeF2, OPrF2, and OTbF2 molecules have higher frequency Ln–O stretching modes. The Ce is assigned to the IV oxidation state and the Pr and Tb are assigned to a mixed III/IV oxidation state. The remaining OLnF2 compounds have lower Ln–O stretches, and the Ln is in the III oxidation state and the O is in the −1 oxidation state. For all of the OLnF compounds, the metal is in the III oxidation state, and the Ln–F bonds are ionic. In OCeF2, ...
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Formation of metal oxyfluorides from specific metal reactions with Oxygen Difluoride: infrared spectroscopic and theoretical investigations of the OScF2 radical and OScF with terminal single and triple Sc-O bonds.
Chemistry (Weinheim an der Bergstrasse Germany), 2012Co-Authors: Yu Gong, Lester Andrews, Charles W. BauschlicherAbstract:The scandium oxyDifluoride free radical, OScF(2), is produced by the spontaneous, specific reaction of laser ablated Sc atoms with OF(2) in solid argon and characterized by using matrix infrared spectroscopy and theoretical calculations. The OScF(2) molecule is predicted to have C(2v) symmetry and a (2)B(2) ground state with an unpaired electron located primarily on the terminal Oxygen atom, which makes it a scandium Difluoride molecule coordinated by a neutral Oxygen atom radical in forming the Sc-O single bond. The closed shell singlet OScF molecule with an obtuse bent geometry has a much shorter Sc-O bond of 1.682 A than that of the OScF(2) radical (1.938 A) on the basis of B3LYP calculations. The Sc-O bond in OScF consists of two covalent bonds and a dative bond in which the Oxygen 2p(π) lone pair donates electron density into an empty Sc 3d orbital thus forming a triple oxo bond. Density functional calculations suggest it is highly exothermic for fluorine transfer from OF(2) to scandium, which favors the formation of the OScF(2) radical species as well as the OScF molecule after fluorine loss.
Thomas M. Klapötke - One of the best experts on this subject based on the ideXlab platform.
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A theoretical investigation of the reaction of Oxygen Difluoride with nitrosyl fluoride
Journal of Fluorine Chemistry, 2000Co-Authors: Thomas M. Klapötke, Richard D. HarcourtAbstract:Abstract The reaction of Oxygen Difluoride, OF 2 , with nitrosyl fluoride, NOF, afforded as the main products FNO 2 , F 2 , NF 3 and O 2 . No ONF 3 was detected as a major product. Likely mechanisms to account for the formation of the observed products have been proposed on the basis of high level ab initio computations. According to ab initio calculations, OF 2 reacts in a bimolecular reaction with NOF according either (i) forming FNO 2 and F 2 directly or (ii) forming the peroxide species F 2 N–O–O–F as an unstable intermediate which then decomposes in an unimolecular decomposition to yield NF 3 and O 2 . The likely intermediate compound F 2 N–O–O–F was shown using quantum chemical calculations to possess a true minimum on its potential energy surface and the structure and vibrational data of F 2 N–O–O–F were calculated at MP2(FULL)/6-311G(d) level of theory.
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Possible intermediate formation of cyclic nitrous oxide, N2O: Reaction of Oxygen Difluoride, OF2, with cesium azide, CsN3
Inorganic chemistry, 1999Co-Authors: Margaret-jane Crawford, Thomas M. KlapötkeAbstract:The reaction of OF2 with NaN3 or CsN3 yielded dinitrogen and nitrous oxide. The formation of nitrous oxide (N2O) from the reaction of OF2 with CsN3 is proposed to occur through the intermediate formation of O(N3)2 which decomposes into two equivalents of N2 and cyclic N2O which is formed initially and then rearranges to give the more stable linear isomer (C∞v).
De-chao Wang - One of the best experts on this subject based on the ideXlab platform.
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The X̃ 2B1, 2B2, 2A1, and 2A2 states of Oxygen Difluoride cation (F2O+): High-level ab initio calculations and simulation of the ultraviolet photoelectron spectrum of F2O
The Journal of Chemical Physics, 2001Co-Authors: De-chao Wang, Foo-tim Chau, Daniel K. W. Mok, Edmond P. F. Lee, Levi Beeching, J. Steven Ogden, John M. DykeAbstract:The ultraviolet photoelectron spectrum of F2O was recorded with a higher resolution than previously published. New vibrational structure was observed in the second and third bands. Near state-of-the-art molecular orbital calculations were performed on the X 1A1 state of F2O and the X 2B1, 2B2, 2A1, and 2A2 state of F2O+, and their potential energy functions were computed. Spectral simulations based on Franck–Condon factor calculations including the Duchinsky effect were carried out within the harmonic oscillator model and also with the inclusion of anharmonicity, in order to assist spectral assignment. Based on the computed ionization energies obtained with the coupled cluster and multireference configuration interaction methods with basis sets of up to quintuple zeta quality, the order of the low-lying cationic states of F2O+ has been firmly established. However, the detailed assignment of the overlapping second and third photoelectron bands was only achieved with the aid of spectral simulation. The it...
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the x 2b1 2b2 2a1 and 2a2 states of Oxygen Difluoride cation f2o high level ab initio calculations and simulation of the ultraviolet photoelectron spectrum of f2o
Journal of Chemical Physics, 2001Co-Authors: De-chao Wang, Foo-tim Chau, Daniel K. W. Mok, Edmond P. F. Lee, Levi Beeching, Steven J Ogden, John M. DykeAbstract:The ultraviolet photoelectron spectrum of F2O was recorded with a higher resolution than previously published. New vibrational structure was observed in the second and third bands. Near state-of-the-art molecular orbital calculations were performed on the X 1A1 state of F2O and the X 2B1, 2B2, 2A1, and 2A2 state of F2O+, and their potential energy functions were computed. Spectral simulations based on Franck–Condon factor calculations including the Duchinsky effect were carried out within the harmonic oscillator model and also with the inclusion of anharmonicity, in order to assist spectral assignment. Based on the computed ionization energies obtained with the coupled cluster and multireference configuration interaction methods with basis sets of up to quintuple zeta quality, the order of the low-lying cationic states of F2O+ has been firmly established. However, the detailed assignment of the overlapping second and third photoelectron bands was only achieved with the aid of spectral simulation. The it...
Jorge R Barrio - One of the best experts on this subject based on the ideXlab platform.
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Identification and quantitation of gaseous compounds of fluorine generated in [18F]F2 target systems
Nuclear medicine and biology, 1996Co-Authors: Allyson Bishop, Nagichettiar Satyamurthy, Gerald Bida, Michael E. Phelps, Jorge R BarrioAbstract:The first direct evidence for the chemical identity of the electrophilic fluorinating agents generated in 20Ne(d, alpha)18F (single-step), 18O(p,n)18F (single-step and two-step) and 16O(3He2+, p)18F (single-step) gas target systems, utilizing aluminum, silver, copper, nickel and gold plated copper target bodies, has been established with multinuclear NMR and mass spectral techniques. The major components of the reactive fraction from these targets were also quantitated using 19F NMR. Fluorine-19 NMR data of the reactive fraction of all proton and 3He2+ irradiated Oxygen gas target systems showed the presence of Oxygen Difluoride in various proportions. Samples from the single-step method contained up to 20% OF2 while those from the two-step process had 0-5%. Fluorine nitrate (FONO2) was observed only as a minor component (0-3%) in the reactive fraction. The presence of OF2 and FONO2 was further confirmed by 17O and 15N NMR, respectively, using [17O]O2 and [15N]N2 spiked Oxygen gas targets. The NMR results were supported by mass spectral data collected with a residual gas analyzer (RGA). Both 19F NMR and mass spectroscopy showed CF4 as the only major inert component in the single-step Oxygen target products. As expected, the 19F NMR and mass spectral data showed that the reactive fraction of the neon gas target constituted only F2 and the inert fraction comprised of CF4 and NF3.
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regioselective synthesis of 6 fluorodopamine 6 fluoro m tyramine and 4 fluoro m tyramine using elemental fluorine Oxygen Difluoride and acetyl hypofluorite
Journal of Fluorine Chemistry, 1995Co-Authors: Mohammad Namavari, Nagichettiar Satyamurthy, Jorge R BarrioAbstract:Abstract 6-Fluorodopamine was regioselectively synthesized in good yields from N -(trifluoroacetyl)-3,4-di-t-butoxycarbonyloxy-6-(trimethylstannyl)phenylethylamine (6) via a fluorodestannylation reaction using F 2 OF 2 or CH 3 COOF followed by acid hydrolysis. Similarly, 6-fluoro- m -tyramine (14) and 4-fluoro- m -tyramine (20) were prepared from their corresponding trimethylstannyl derivatives. All precursors and products were fully characterized by multinuclear NMR spectroscopy and high resolution mass spectrometry.
