Barium

Fischer, Karl F.; Puchelt, H.

doi:10.1007/978-3-642-65039-0_22

Cited by 5 publications

(1 citation statement)

References 277 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…BVS are 5.74 for U 23 and 4.96 for P. 24 The coordination number (11) of barium is greater than in 1 (see above). 25 The Ba−O bond distances range from 2.666(9) to 3.230(5) Å, which results in a bond valence sum of 2.02 for Ba(1) in 2 (Table S5, Supporting Information). (PO 4 ) 2 ] Polymorphs.…”

Section: +mentioning

confidence: 99%

Highly Distorted Uranyl Ion Coordination and One/Two-Dimensional Structural Relationship in the Ba₂[UO₂(TO₄)₂] (T = P, As) System: An Experimental and Computational Study

Kowalski

et al. 2014

Inorg. Chem.

View full text Add to dashboard Cite

Uranium compounds α-Ba 2 [UO 2 (PO 4 ) 2 ] (1), β-Ba 2 [UO 2 (PO 4 ) 2 ] (2), and Ba 2 [UO 2 (AsO 4 ) 2 ] (3) were synthesized by H 3 BO 3 /B 2 O 3 flux reactions, though boron is not incorporated into the structures. Phases 1 and 2 are topologically identical, but 1 is heavily distorted with respect to 2. An unusual UO 7 pentagonal bipyramid occurs in 1, exhibiting a highly distorted equatorial configuration and significant bending of the uranyl group, due to edge-sharing with one neighboring PO 4 3− tetrahedron. Compound 2 contains more normal square bipyramids that share corners with four neighboring PO 4 3− tetrahedra, but the uranyl cation UO 2 2+ is tilted relative to the equatorial plane. Experimental evidence as well as density functional theory (DFT) calculations suggest that 1 is more stable than 2. In theory, 1 and 2 can interconvert by forming/releasing the shared edge between the uranyl polyhedron and the phosphate tetrahedron. Similar fundamental building blocks in β-Ba 2 [UO 2 (PO 4 ) 2 ] and Ba 2 [UO 2 (AsO 4 ) 2 ] indicate a possible evolution of uranyl-based structures from chain to layer type and formation of an accretional series.

show abstract

Section: +mentioning

confidence: 99%