Silver indium diphosphate, AgInP2O7

Hafid Zouihri; Mohamed Saadi; Boujemaa Jaber; Lehcen El Ammari

doi:10.1107/S1600536810052451

. 2010 Dec 18;67(Pt 1):i2. doi: 10.1107/S1600536810052451

Silver indium diphosphate, AgInP₂O₇

Hafid Zouihri ^a,^*,^‡, Mohamed Saadi ^a, Boujemaa Jaber ^b, Lehcen El Ammari ^a

PMCID: PMC3050398 PMID: 21522510

Abstract

Polycrystalline material of the title compound, AgInP₂O₇, was synthesized by traditional high-temperature solid-state methods and single crystals were grown from the melt of a mixture of AgInP₂O₇ and B₂O₃ as flux in a platinium crucible. The structure consists of InO₆ octahedra, which are corner-shared to PO₄ tetrahedra into a three-dimensional network with hexagonal channels running parallel to the c axis. The silver cation, located in the channel, is bonded to seven O atoms of the [InP₂O₇] framework with Ag–O distances ranging from 2.370 (2) to 3.015 (2) Å. The P₂O₇ diphosphate anion is characterized by a P—O—P angle of 137.27 (9) and a nearly eclipsed conformation. AgInP₂O₇ is isotypic with the M ^IFeP₂O₇ (M ^I = Na, K, Rb, Cs and Ag) diphosphate family.

Related literature

For properties of M ^IFeP₂O₇ (M ^I = Na, K, Rb, Cs and Ag) diphosphates, see: Terebilenko et al. (2010 ▶); Hizhnyi et al. (2008 ▶); Whangbo et al. (2004 ▶); Vitins et al. (2000 ▶). For isotypic structures, see: Belkouch et al. (1995 ▶); Gabelica-Robert et al. (1982 ▶); Moya-Pizarro et al. (1984 ▶); Mercader et al. (1990 ▶).

Experimental

Crystal data

AgInP₂O₇
M _r = 396.63
Monoclinic,
a = 7.4867 (3) Å
b = 8.2620 (3) Å
c = 9.8383 (5) Å
β = 112.038 (2)°
V = 564.09 (4) Å³
Z = 4
Mo Kα radiation
μ = 8.11 mm⁻¹
T = 296 K
0.08 × 0.06 × 0.05 mm

Data collection

Bruker X8 APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1999 ▶) T _min = 0.563, T _max = 0.667
21692 measured reflections
3730 independent reflections
3245 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.021
wR(F ²) = 0.048
S = 1.03
3730 reflections
101 parameters
Δρ_max = 1.62 e Å⁻³
Δρ_min = −2.04 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810052451/br2154sup1.cif

e-67-000i2-sup1.cif^{(14.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810052451/br2154Isup2.hkl

e-67-000i2-Isup2.hkl^{(179.2KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors thank the Unit of Support for Technical and Scientific Research (UATRS, CNRST) for the X-ray data collection.

supplementary crystallographic information

Comment

The diphosphates A^IM^IIIP₂O₇ (A^I = Li, Na, K, Rb, Cs and Ag; M^III = Al, Ga, Cr, Fe, In, Y) are extensively studied for their electrical and optical properties and for its perspective application as magnetic materials (Terebilenko et al. (2010); Hizhnyi et al. (2008); Whangbo et al. (2004); Vitins et al. (2000)). The crystal structures of most of these compounds are known except a few cases in which the crystal growth is difficult. In this context, the present paper reports on the determination of AgInP₂O₇ crystal structure from X-ray diffraction single-crystal data.

The structure of this phosphate is characterized by a three-dimensional network built up from indum octahedra linked to diphosphate groups by a corner-sharing. Each InO₆ octahedra is surrounded by six PO₄ tetrahedra belonging to five different P₂O₇ groups (see Fig.1 and Fig.2). As a result of these blocks, assemblage three-dimensional-framework is formed with hexagonal channels, where silver cations reside. Although, the coordination sphere of Ag⁺ cations is composed of seven O^2- anions in an irregular geometry, located at Ag–O distances between 2.370 (2) and 3.015 (2) Å (see Fig.2). Furthermore, the diphosphate group contains two distorted PO₄ tetrahedra sharing one corner and display a nearly eclipsed conformation. The P–O bond-lengths range between 1.492 (2) Å for terminal P1–O1 and 1.606 (2) Å for the bridging P2–O7 bond. Therefore, a P1–O7–P2 angle of 137.27 (9) ° is wider than 133.6 (3)° and 132.9 (3) ° reported for both AgFeP₂O₇ and NaFeP₂O₇ respectively (Belkouch et al. (1995); Gabelica-Robert et al. (1982); Moya-Pizarro et al. (1984); Mercader et al. (1990)).

Silver indium diphosphate (pyrophosphate) is isostructural to A^IFeP₂O₇ (A^I = Na, K, Rb, Cs and Ag) diphosphates family and is categorized as a dichromate type.

Experimental

AgInP₂O₇ in the form of single crystals was prepared by stoichiometric reaction of AgNO₃, (NH₄)₂HPO₄ and In₂O₃ in B₂O₃ flux. The mixture was heated at 773 K under ambiante atmosphere for 6 h and 973 K for 2 h with intermediate grindings to ensure complete reaction. Subsequent melting at 1323 K followed by slow cooling to room temperature at a rate of 12°K h^-1 resulted in colourless crystals of the title compound.