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Bonding Interactions in Uranyl α-Diimine Complexes: A Spectroscopic and Electrochemical Study of the Impacts of Ligand Electronics and Extended Conjugation

“…The symmetric (ν 1 , Raman active) and asymmetric (ν 3 , IR active) vibrational modes are characteristic of the uranyl moiety, − making vibrational spectroscopy a useful probe to evaluate ligand influence on axial interactions. It has been well-established that uranyl stretching frequencies are strongly indicative of the binding strength of the equatorial ligands and can therefore serve as a measure of covalency. − The large assembly of compounds presented herein represents a unique opportunity to examine the impacts of both R-group substitution and degree of ligand conjugation on the axial -yl interactions. The IR spectra featuring the ν 3 stretches of the two sets of uranyl complexes (gbha and phen-BIAN) are shown in Figure .…”

Study of uranyl sorption onto hematite by in situ attenuated total reflection–infrared spectroscopy

“…The uranyl ion UO 2+ 2 is as a linear molecule (O=U=O), with a U=O distance in the range 0.17-0.19 nm [14]. There are two fundamental uranyl stretchings: the symmetric stretching (ν s ) observed in Raman spectroscopy around 870 cm −1 and the antisymmetric stretching (ν as ) observed in infrared spectroscopy around 920 cm −1 for the free uranyl ion in water [15].…”

Sorption of uranyl ions on titanium oxide studied by ATR-IR spectroscopy

“…This result supports the decomposition into two distinct vibration frequencies of U=O bond. This frequency is linked to the U=O equilibrium distance (R U=O ) according to Badger's equation[30] R U=O = a + bν With values for a and bproposed by Syt'ko and Kabaeva[31] (a = 0.1, b = 7.16), R U=O of 0.177 and 0.176 nm is respectively found for 905 and 920 cm −1 bands. The difference is slight, but should be correlated to a difference in the chemical environment of uranyl ions.…”