Uranyl/12-crown-4 Ether Complexes and Derivatives: Structural Characterization and Isomeric Differentiation

Abstract

The following gas-phase uranyl/12-crown-4 (12C4) complexes were synthesized by electrospray ionization:which spontaneously adds water to yield [UO 2 (12C4-H)-(H 2 O)] + . The latter has the same composition as complex [ U O 2 ( 1 2 C 4 ) ( O H ) ] + p r o d u c e d b y C I D o f [UO 2 (12C4) 2 (OH)] + but exhibits different reactivity with water. The postulated structures as isomeric [UO 2 (12C4-H)(H 2 O)] + and [UO 2 (12C4)(OH)] + were confirmed by comparison of infrared multiphoton dissociation (IRMPD) spectra with computed spectra. The structure of [UO 2 (12C4-H)] + corresponds to cleavage of a C−O bond in the 12C4 ring, with formation of a discrete U−O eq bond and equatorial coordination by three intact ether moieties. Comparison of IRMPD and computed IR spectra furthermore enabled assignment of the structures of the other complexes. Theoretical studies of the chemical bonding features of the complexes provide an understanding of their stabilities and reactivities. The results reveal bonding and structures of the uranyl/12C4 complexes and demonstrate the synthesis and identification of two different isomers of gas-phase uranyl coordination complexes.

Destruction of the Uranyl Moiety in a U(V) “Cation–Cation” Interaction

“…The mass spectrum obtained for ESI of a solution of UO 2 Cl 2 :12C4 (1:4 in ethanol/<10% water) was reported previously and is shown in Figure S1. The previous focus was on complexes of one uranyl coordinated by 12C4.…”

“…14 As a result, crown ethers have potential for actinide partitioning from nuclear waste, [15][16] particularly via size-specificity. [17][18][19][20] Gas-phase actinide crown ether complexes, including of uranyl, present a means to elucidate factors that affect complexation and coordination, including geometric effects that may be supported by distinctive crown geometries. 18,20 In the present work we extend this general line of inquiry from mononuclear uranyl-crown complexes to dimeric uranyl complexes, with an aim to understand how crown ethers might act as bridging ligands and support novel bonding motifs such as cation-cation interactions.…”

Trends in the Electronic Structure and Chemical Bonding of a Series of Porphyrinoid–Uranyl Complexes

“…As it is apparent in Figure , [UO 2 (POR)] and [UO 2 (COR)] − share a similarity in the coordination phenomenon that the uranyl resides above the L 4 ligand in [UO 2 (L 4 )] 0/1– and lies between two ligands in [UO 2 (L 4 ) 2 ] 2–/4– . These structures have been commonly reasonable because the small cavities of these two ligands are not enough to accommodate uranyl ions, which have been found in actinyl crown ether complexes. − The side-on complexes are undercoordinated, which further tend to coordinate with other molecules to satisfy the equatorial coordination. For example, the [UO 2 (ORA)­(H 2 O) 2 ] − with two-water coordination shows a larger B.E, compared to that of side-on [UO 2 (ORA)] − (Table S1).…”

Relativistic Effects Stabilize the Planar Wheel-like Structure of Actinide-Doped Gold Clusters: An@Au7 (An = Th to Cm)

“…However, this investigation is still challenging for both direct experiments and theoretical calculations on actinide–gold clusters, especially for transuranic elements, accounting for the lack of comprehensive understanding of the electronic and structural properties of actinide compounds. Lately, the combination of advanced quantum chemistry and the modern bonding theory has become effective means that could provide essential knowledge and comprehensions of these systems. , Herein, we performed complete theoretical calculations using the combination of advanced quantum chemistry and the modern bonding theory on the An@Au 7 (An = Th to Cm), UCM 7 (CM = Cu, Ag, Au), and WAu 7 clusters, to investigate the periodic trend in their electronic and structural features, as well as the chemical bonding between An and CM 7 .…”

“…Lately, the combination of advanced quantum chemistry and the modern bonding theory has become effective means that could provide essential knowledge and comprehensions of these systems. 66,67 Herein, we performed complete theoretical calculations using the combination of advanced quantum chemistry and the modern bonding theory on the An@Au 7 (An = Th to Cm), UCM 7 (CM = Cu, Ag, Au), and WAu 7 clusters, to investigate the periodic trend in their electronic and structural features, as well as the chemical bonding between An and CM 7 .…”