The Formula of Uranyl Ion

Crandall, H.W.

doi:10.1063/1.1747345

Cited by 51 publications

(48 citation statements)

References 9 publications

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“…Facile OH exchange as compared with O yl exchange is in accord with the rationale presented by Crandall that a covalent U−O yl bond should be more resistant to disruption than an ionic U−OH bond. 1 The O yl exchange efficiency for UO 2 + was much greater than for NpO 2 + and PuO 2 + . DFT results for UO 2 + , NpO 2 + , and PuO 2 + indicate a substantially higher energy transition state for the latter two, in accord with the observations.…”

Section: ■ Conclusionmentioning

confidence: 98%

On the Origins of Faster Oxo Exchange for Uranyl(V) versus Plutonyl(V)

et al. 2012

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Activation of uranyl(V) oxo bonds in the gas phase is demonstrated by reaction of U(16)O(2)(+) with H(2)(18)O to produce U(16)O(18)O(+) and U(18)O(2)(+). In contrast, neptunyl(V) and plutonyl(V) are comparatively inert toward exchange. Computed potential energy profiles (PEPs) reveal a lower yl oxo exchange transition state for uranyl(V)/water as compared with neptunyl(V)/water and plutonyl(V)/water. A correspondence between oxo exchange rates in gas phase and acid solutions is apparent; the contrasting oxo exchange rates of UO(2)(+) and PuO(2)(+) are considered in the context of covalent bonding in actinyls. Hydroxo exchange of U(16)O(2)((16)OH)(+) with H(2)(18)O to give U(16)O(2)((18)OH)(+) proceeded much faster than oxo exchange, in accord with a lower computed transition state for OH exchange. The PEP for the addition of H(2)O to UO(2)(+) suggests that both UO(2)(+)·(H(2)O) and UO(OH)(2)(+) should be considered as potential products.

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Section: ■ Conclusionmentioning

confidence: 98%

On the Origins of Faster Oxo Exchange for Uranyl(V) versus Plutonyl(V)

et al. 2012

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“…42 These equatorial aqua ligands are labile and interchange with the aqueous media, whereas the two oxygen centers of uranyl are inert with respect to substitution. 96,97 Quite a few theoretical studies 7-9,15-18,53 computed the effects of hydration on UO 2 2+ considering 4, 5, and 6 water molecules in the equatorial plane. On the basis of solvation energetics, several authors identified the pentacoordinated complex as energetically preferred.…”

Section: Chloro Complexes [Ano 2 CL 4 ] 2- [Uo 2 Cl 4 ] 2-mentioning

confidence: 99%

Systematic DFT Study of Gas Phase and Solvated Uranyl and Neptunyl Complexes [AnO₂X₄]ⁿ (An = U, Np; X = F, Cl, OH, n = −2; X = H₂O, n = +2)

et al. 2006

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The six-valent uranyl and neptunyl complexes [An(VI)O2X4]n (An = U, Np; X = F, Cl, OH, n = -2; X = H2O, n = +2) have been studied within the framework of density functional theory. The relative stabilities of the cis and trans isomers, structural properties, charge distribution, and ligand binding energies have been determined using the modified Perdew-Burke-Ernzerhof functional at the all-electron scalar relativistic level. Uranyl and neptunyl complexes with different ligands have been compared in a systematic fashion, demonstrating close similarity of these actinides in oxidation state VI. In addition, the effect of an aqueous solution has been taken into account with the polarizable continuum model COSMO. Computed averaged ligand binding energies permit one to rationalize the observed different stabilities of the title species in aqueous media.

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“…22 They obtained IR spectra for neutral uranyl hexafluoroacetylacetonate (hfac) adducts with additional basic ligands. The bare 4 complex, which can simplistically be formulated as UO 2 2+ (hfac -) 2 , exhibited a ν 3 of 958 cm -1 .…”

Section: Introductionmentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] The infrared (IR) active asymmetric v 3 stretching mode of uranyl has been studied extensively in both condensed and gas phases, with a focus on the effect of ligation on the frequency. In aqueous solution the hydrated uranyl ν 3 frequency is close to 963 cm -1 .…”

Section: Introductionmentioning

confidence: 99%

Infrared Multiphoton Dissociation Spectroscopy of a Gas-Phase Complex of Uranyl and 3-Oxa-Glutaramide: An Extreme Red-Shift of the [O═U═O]²⁺ Asymmetric Stretch

Gibson

Stipdonk

et al. 2015

J. Phys. Chem. A

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The gas-phase complex UO2(TMOGA)2(2+) (TMOGA = tetramethyl-3-oxa-glutaramide) prepared by electrospray ionization was characterized by infrared multiphoton dissociation (IRMPD) spectroscopy. The IRMPD spectrum from 700-1800 cm(-1) was interpreted using a computational study based on density functional theory. The predicted vibrational frequencies are in good agreement with the measured values, with an average deviation of only 8 cm(-1) (<1%) and a maximum deviation of 21 cm(-1) (<2%). The only IR peak assigned to the linear uranyl moiety was the asymmetric ν3 mode, which appeared at 965 cm(-1) and was predicted by DFT as 953 cm(-1). This ν3 frequency is red-shifted relative to bare uranyl, UO2(2+), by ca. 150 cm(-1) due to electron donation from the TMOGA ligands. Based on the degree of red-shifting, it is inferred that two TMOGA oxygen-donor ligands have a greater effective gas basicity than the four monodentate acetone ligands in UO2(acetone)4(2+). The uranyl ν3 frequency was also computed for uranyl coordinated by two TMGA ligands, in which the central Oether of TMOGA has been replaced by CH2. The computed ν3 for UO2(TMGA)2(2+), 950 cm(-1), is essentially the same as that for UO2(TMOGA)2(2+), suggesting that electron donation to uranyl from the Oether of TMOGA is minor. The computed ν3 asymmetric stretching frequencies for the three actinyl complexes, UO2(TMOGA)2(2+), NpO2(TMOGA)2(2+) and PuO2(TMOGA)2(2+), are comparable. This similarity is discussed in the context of the relationship between ν3 and intrinsic actinide-oxygen bond energies in actinyl complexes.

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The Formula of Uranyl Ion

Cited by 51 publications

References 9 publications

On the Origins of Faster Oxo Exchange for Uranyl(V) versus Plutonyl(V)

On the Origins of Faster Oxo Exchange for Uranyl(V) versus Plutonyl(V)

Systematic DFT Study of Gas Phase and Solvated Uranyl and Neptunyl Complexes [AnO₂X₄]ⁿ (An = U, Np; X = F, Cl, OH, n = −2; X = H₂O, n = +2)

Infrared Multiphoton Dissociation Spectroscopy of a Gas-Phase Complex of Uranyl and 3-Oxa-Glutaramide: An Extreme Red-Shift of the [O═U═O]²⁺ Asymmetric Stretch

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The Formula of Uranyl Ion

Cited by 51 publications

References 9 publications

On the Origins of Faster Oxo Exchange for Uranyl(V) versus Plutonyl(V)

On the Origins of Faster Oxo Exchange for Uranyl(V) versus Plutonyl(V)

Systematic DFT Study of Gas Phase and Solvated Uranyl and Neptunyl Complexes [AnO2X4]n (An = U, Np; X = F, Cl, OH, n = −2; X = H2O, n = +2)

Infrared Multiphoton Dissociation Spectroscopy of a Gas-Phase Complex of Uranyl and 3-Oxa-Glutaramide: An Extreme Red-Shift of the [O═U═O]2+ Asymmetric Stretch

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Systematic DFT Study of Gas Phase and Solvated Uranyl and Neptunyl Complexes [AnO₂X₄]ⁿ (An = U, Np; X = F, Cl, OH, n = −2; X = H₂O, n = +2)

Infrared Multiphoton Dissociation Spectroscopy of a Gas-Phase Complex of Uranyl and 3-Oxa-Glutaramide: An Extreme Red-Shift of the [O═U═O]²⁺ Asymmetric Stretch