Novel Fundamental Building Blocks and Site Dependent Isomorphism in the First Actinide Borophosphates

Abstract

( 5 -y ) -As y O (20-x) (OH) x }] (x = 1.43, y = 2.24) (AgNBPU-3), have been prepared by the H 3 BO 3 −NH 4 H 2 PO 4 /NH 4 H 2 AsO 4 flux method. The structure of AgNBPU-1 has an unprecedented fundamental building block (FBB), composed of three BO 4 and six PO 4 tetrahedra which can be written as 9□:[Φ] □⟨3□⟩□|□⟨3□⟩□|□⟨3□⟩□|. Two Ag atoms are linearly coordinated; the coordination of a third one is T-shaped. AgNBPU-2 and AgNBPU-3 are isostructural and possess a FBB of two BO 4 and five TO 4 (T = P, As) tetrahedra (7□:□⟨4□⟩□|□). AgNBPU-3 is a solid solution with some PO 4 tetrahedra of the AgNBPU-2 end-member being substituted by AsO 4 . Only two out of the three independent P positions are partially occupied by As, resulting in site dependent isomorphism. The three compounds represent the first actinide borophosphates.

Triple‐Vertex Linkage of (BO4)‐Tetrahedra in a Borosulfate: Synthesis, Crystal Structure, and Quantum‐Chemical Investigation of Sr[B3O(SO4)4(SO4H)]

“…where [F] stands for the bridging m 3 oxygen atom. [14] These FBBs form the anionic chains with the Niggli formula [15] The BÀO bond lengths are similar to our findings and fall in the narrow range of 1.490(18) to 1.568 (11) . However, in this compound the charge compensation of the heteropolyanion is achieved by multiple, partially highly charged cations.…”

Porous Uranyl Borophosphates with Unique Three-Dimensional Open-Framework Structures

“…This, speculatively, can be a reason why KUPB2 has more uranium compared to KUPB1 . In comparison, the first three actinide borophosphates, Ag 2 (NH 4 ) 3 (UO 2 ) 2 B 3 O­(PO 4 ) 4 (PO 4 H) 2 H 2 O, Ag 0.74 (NH 4 ) 3 (UO 2 ) 2 B 2 P 5 O 18.74 (OH) 1.26 , and Ag 0.57 ­(NH 4 ) 3 ­(UO 2 ) 2 ­B 2 P 2.76 ­As 2.24 O 18.57­ (OH) 1.43 , prepared with a H 3 BO 3 /NH 4 H 2 PO 4 flux method at around 200 °C used considerably less water (50 μL) . For comparison with the syntheses of the first series of uranyl borophosphates made by Wu et al, we attempt to synthesize KUPB1 and KUPB2 by changing H 3 PO 3 to NH 4 H 2 PO 4 ; however, all syntheses were unsuccessful.…”

“…The first three actinide borophosphates isolated and reported, Ag 2 (NH 4 ) 3 (UO 2 ) 2 B 3 O­(PO 4 ) 4 (PO 4 H) 2 H 2 O, Ag 0.74 (NH 4 ) 3 (UO 2 ) 2 B 2 P 5 O 18.74 (OH) 1.26 , and Ag 0.57 (NH 4 ) 3 (UO 2 ) 2 B 2 P 2.76 As 2.24 O 18.57 (OH) 1.43 , show structural motifs similar to that of the aforementioned borate–phosphates in the case of Ag 2 (NH 4 ) 3 (UO 2 ) 2 B 3 O­(PO 4 ) 4 (PO 4 H) 2 H 2 O, forming a 2D-layered structure, whereas Ag 0.74 (NH 4 ) 3 (UO 2 ) 2 B 2 P 5 O 18.74 (OH) 1.26 and Ag 0.57 (NH 4 ) 3 (UO 2 ) 2 B 2 P 2.76 As 2.24 O 18.57 (OH) 1.43 show a more intricate 3D assemblage. Interestingly, both sets of described borate–phosphate and borophosphate structures possess porous inorganic 3D open frameworks.…”

“…The first three actinide borophosphates isolated and reported, 30 . 32 Such an exceptional and successful application was attributed to its highly porous open-framework structure and disordered anionic borate groups.…”

Hydrothermal Synthesis and Structural Investigation of a Crystalline Uranyl Borosilicate

“…It is therefore unsurprising that incorporation of mixed-oxoanions into the structures of uranyl compounds often facilitates further structural diversity. For example, a few uranyl borophosphate [25,26], borogermanate [27], aluminoborate [28], and aluminophosphate [29] compounds are known, most of which exhibit complex open-framework structures. No such uranyl compounds containing borosilicate units have been reported, although there are several existing non-uranyl compounds exhibiting a variety of different borosilicate units.…”