Orthorhombic barium dihydrogenphosphate

Abstract

Abstract. Ba(H2PO4)2, space group Pccn, a = 7.7962 (10), b = 10.2574 (10), c = 8.5653 (ll) A at 295 K (2 = 1.54051 A), Z = 4, D x = 3.212, D m = 3.21 g cm -3. A corrugated network of hydrogenbonded phosphate groups lies parallel to the ac plane with Ba--O coordination bonds running between the phosphate layers. The eight Ba-O distances range from 2.659 (2) to 2.903 (2) A. The phosphate distances are: P-OH 1.579 (2) and 1.576 (2) A, and P-O 1.495 (2) and 1.490 (2) A. Introduction.Colorless rhombic platelets of Ba(H2PO4) 2 were grown by slow evaporation from a solution of 10 g of barium phosphate in 200 g of a 10% aqueous solution of H3PO 4. The space group, Pccn, is indicated by mmm Laue symmetry with systematic absences for Okl and hOl (l odd) and hkO (h + k odd). Crystal density was measured by flotation in a mixture of tetrabromoethane and diiodomethane.The data crystal was cut to 0.5 × 0.45 × 0.45 mm and mounted on a four-circle automated diffractometer with ~0 approximately along [320]. Cell constants were determined by least-squares fit from 20, 09 and Z values measured with the resolved Cu Ktq line for 25 reflections in the range 73 ° < 20 < 88 °. Intensity data

Mo6+ Cation Enrichment of the Structure Chemistry of Iodates: Syntheses, Structures, and Calculations of Ba(MoO2)2(IO3)4O, Ba3[(MoO2)2(IO3)4O(OH)4]·2H2O, and Sr[(MoO2)6(IO4)2O4]·H2O

“…These [Mo 2 O 11 ] 10– dimers are linked by isolated [IO 3 ] − units to build 2D [(MoO 2 ) 2 (IO 3 ) 4 O] 2– layers (Figure b), which are separated by the Ba 2+ cations (Figure d). The Ba 2+ cations are coordinated to eight O atoms, forming a [BaO 8 ] 14– (Figure c) bicapped trigonal prism with Ba–O distances in the range of 2.747(3)–2.990(3) Å, which are comparable with those of other reported compounds, such as Ba­(H 2 PO 4 ) 2 (2.659(1)–2.903(2) Å) and Ba 2 (B 5 O 8 (OH) 2 )­(OH) (2.620(6)–2.864(4) Å). , All of the I 5+ cations exhibit the typical [IO 3 ] − pyramid with the I–O bond lengths ranging from 1.786(3) to 1.899(3) Å, which are similar to those found in RbAu­(IO 3 ) 4 …”

Insights into Formation Conditions, Crystal Structures, and Thermal Behavior of Hydrous and Anhydrous Barium Arsenates

“…Ba­(H 2 AsO 4 ) 2 crystallizes isotypically with the triclinic form of Ba­(H 2 PO 4 ) 2 . , Whereas barium dihydrogen phosphate is dimorphic with an orthorhombic symmetry for the second polymorph, , there are no indications for dimorphism of Ba­(H 2 AsO 4 ) 2 as evidenced by X-ray diffraction and thermal analysis. In the two original crystal stucture studies of triclinic Ba­(H 2 PO 4 ) 2 , , the cell settings differ from each other, each with a different nonreduced cell, and only in one of the studies, hydrogen positions have been determined .…”

Dependence of the distortion of the tetrahedra in acid phosphate groups H n PO4 (n = 1–3) on hydrogen-bond length

“…This leads to longer P-O lengths, smaller OPO angles and shorter O-O lengths. Among the structures studied, this 'edge-sharing' coordination and its effects are discussed in Ca(H2PO4)2.H20 (Dickens & Bowen, 1971), Ca(H2PO4)2 (Dickens, Prince, Schroeder & Brown, 1973), .orthorhombic Ba(H2PO4)2 (Gilbert, Lenhert & Wilson, 1977;Prelesnik, Herak, (~uri6 & Krstanovi6, 1978), triclinic Ba(H2PO4)2 (Gilbert & Lenhert, 1978) and Ca2(NH4) H7(PO4)4.2H20 (Takagi, Mathew & Brown, 1980). These were not included in the DI(OPO) and DI(OO) diagrams.…”