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The compound Ag1.49Mn1.49IIMn1.51III(AsO4)3 (silver mangan­ese arsenate) was prepared by a solid-state reaction. It crystallizes in the monoclinic system in space group C2/c. The three-dimensional network is built up from MnO6 octahedra, sharing edges which are linked together by the arsenate groups (AsO4). This arrangement delimits two types of hexagonal tunnels which accommodate Ag+ cations. The compound is isostructural with the compounds X(1)X(2)M(1)M(2)2(PO4)3 of the alluaudite structure.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803005816/br6081sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536803005816/br6081Isup2.hkl
Contains datablock I

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](Mn-O) = 0.009 Å
  • R factor = 0.052
  • wR factor = 0.156
  • Data-to-parameter ratio = 11.0

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


Red Alert Alert Level A:
ABSTM_02 Alert A Crystal and compound unsuitable for non-numerical corrections. Product of mu and tmid > 3.0 Value of mu given = 16.919 tmid = 0.200
1 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
0 Alert Level C = Please check

Comment top

Ag1.49MnII1.49MnIII1.51(AsO4)3 crystallize in the monoclinic space group C2/c and is isostructural with the compounds X(1)X(2)M(1)M(2)2(PO4)3 (Moore, 1971;Yakubovitch et al., 1977) of the alluaudite structure type. The framework of Ag1.49MnII1.49MnIII1.51(AsO4)3 consists of infinite chains of MnO6 octahedra, sharing skew edge, running parallel to the [010] direction and having an Mn1–Mn2–Mn2 sequence. A projection of the structure, showing the displacement ellipsoids, is presented in Fig. 1.

In each chain, repetition of the Mn1O6 and Mn2O6 octahedra are ensured by c-glide and inversion centers, respectively. Atoms As2, Mn1 and Ag1 have twofold symmetry, Ag2 are on inversion centers and all other atoms are in general positions. The infinite chains are linked by As1O4 and As2O4 tetrahedra to form sheets parallel to (010). The As2O4 tetrahedra share all four of their vertices with the MnO6 octahedra two with one chain and two with an adjacent chain. The As1O4 tetrahedron shares its four oxygen summits with four different MnO6 octahedra belonging to three chains, two from the same chain and the two from two different chains (Fig. 2). The MnO6 octahedra appear to be highly distorted, especially around Mn1, in which the angle subtended by two of the trans O atoms is 143.9 (2)°. This distortion probably occurs as a result of the need to accommodate to the connectivity of the AsO4 tetrahedra, which are rather rigid entities and are responsible for holding adjacent chains together. This framework defines large tunnels running along the c direction. one tunnel along (0,0,z) and the other along (0, 1/2,z) (Fig. 3). The silver cations Ag1+ and Ag2+ partially occupy these sites in those tunnels. They exhibit two sort of coordination, Ag1+ [site-occupation factor = 0.870 (7)], located in the second type of tunnel, has a square-planar environment, similar to the situation observed in AgCo3PO4(HPO4)2(Guesmi & Driss, 2002) and Ag2+ [site-occupation factor = 0.620 (7)], located in the first type, is linked to six O atoms. For electroneutrality, it is supposed that Mn2 has the oxidation state 2.69, as indicated by the bond-valence sum (Brown & Altermatt, 1985) and based on parameters for Mn2+—O, then the total charge contributed by Mn1 and Mn2 is 1 × 2 + 2 × 2.69 = 7.38, which leaves a charge of 1.62 to be provided by the two tunnel sites, quite close to the vale of 1.49 provided by the X-ray refinement.

Experimental top

Single crystals of Ag1.49MnII1.49MnIII1.51(AsO4)3 were prepared by a conventional solid-state reaction. NH4H2AsO4, MnO and AgNO3 in the (1:2:3) ratio were ground together under acetone in an agate mortar. The mixture was heated in porcelain crucible at 673 K for 4 h, cooled to room temperature, reground, and heated at 1073 K for 24 h, then cooled slowly to room temperature at a rate of 5 K h−1. The product was washed with hot water. Brown parallelepiped-shaped crystals of the title compound were extracted. Their qualitative analysis by electron microscope probe revealed them to contain Ag, As and Mn atoms.

Refinement top

The occupations of the Ag1 and Ag2 sites are 0.870 (7) and 0.620 (7), respectively.

Computing details top

Data collection: CAD-4 EXPRESS (Duisenberg, 1992; Macíček & Yordanov, 1992); cell refinement: CAD-4 EXPRESS; data reduction: MolEN (Fair, 1990); program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. A projection of the structure, showing displacement ellipsoids at the XX% probability level. [Please complete]
[Figure 2] Fig. 2. View showing the association mode between AsO4 tetrahedra (purple) and MnO6 octahedra (cyan).
[Figure 3] Fig. 3. Projection of the structure of Ag1.49MnII1.49MnIII1.51(AsO4)3 along the [001] direction. In this presentation, the corners of the octahedra and tetrahedra are O atoms and the Mn and As atoms are at the center of each octahedron and tetrahedron, respectively. Small solid circles are Ag atoms.
(I) top
Crystal data top
Ag1.49Mn3(AsO4)3F(000) = 1360
Mr = 742.29Dx = 5.062 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 25 reflections
a = 12.262 (2) Åθ = 10.8–13.8°
b = 12.934 (3) ŵ = 16.92 mm1
c = 6.707 (1) ÅT = 293 K
β = 113.690 (2)°Parallelepiped, brown
V = 974.1 (3) Å30.44 × 0.2 × 0.03 mm
Z = 4
Data collection top
Enraf-Nonius CAD-4
diffractometer
829 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.071
Graphite monochromatorθmax = 27.0°, θmin = 2.4°
ω/2θ scansh = 015
Absorption correction: ψ scan
(North et al., 1968)
k = 016
Tmin = 0.178, Tmax = 0.309l = 87
1112 measured reflections2 standard reflections every 120 min
1067 independent reflections intensity decay: 0.4%
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.052 w = 1/[σ2(Fo2) + (0.0825P)2 + 48.2737P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.156(Δ/σ)max < 0.001
S = 1.07Δρmax = 2.61 e Å3
1067 reflectionsΔρmin = 2.08 e Å3
97 parametersExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.0015 (3)
Crystal data top
Ag1.49Mn3(AsO4)3V = 974.1 (3) Å3
Mr = 742.29Z = 4
Monoclinic, C2/cMo Kα radiation
a = 12.262 (2) ŵ = 16.92 mm1
b = 12.934 (3) ÅT = 293 K
c = 6.707 (1) Å0.44 × 0.2 × 0.03 mm
β = 113.690 (2)°
Data collection top
Enraf-Nonius CAD-4
diffractometer
829 reflections with I > 2σ(I)
Absorption correction: ψ scan
(North et al., 1968)
Rint = 0.071
Tmin = 0.178, Tmax = 0.3092 standard reflections every 120 min
1112 measured reflections intensity decay: 0.4%
1067 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0520 restraints
wR(F2) = 0.156 w = 1/[σ2(Fo2) + (0.0825P)2 + 48.2737P]
where P = (Fo2 + 2Fc2)/3
S = 1.07Δρmax = 2.61 e Å3
1067 reflectionsΔρmin = 2.08 e Å3
97 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
As10.26356 (10)0.38996 (9)0.37013 (17)0.0145 (4)
As20.50000.21390 (12)0.25000.0144 (4)
Mn10.50000.23492 (19)0.25000.0160 (6)
Mn20.22059 (19)0.15521 (17)0.1344 (3)0.0271 (5)
Ag10.50000.51173 (14)0.75000.0295 (6)0.870 (7)
Ag20.50000.00000.00000.0299 (9)0.620 (7)
O10.1175 (8)0.4045 (7)0.3085 (17)0.031 (2)
O20.4559 (7)0.2882 (6)0.0243 (12)0.0191 (17)
O30.3344 (8)0.5053 (7)0.3906 (15)0.026 (2)
O40.3351 (7)0.3302 (7)0.6127 (12)0.0206 (18)
O50.2788 (8)0.3175 (8)0.1736 (15)0.028 (2)
O60.3979 (10)0.1304 (8)0.2629 (16)0.039 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
As10.0123 (6)0.0174 (6)0.0121 (6)0.0016 (4)0.0031 (4)0.0051 (4)
As20.0238 (9)0.0082 (8)0.0084 (7)0.0000.0035 (6)0.000
Mn10.0167 (12)0.0115 (11)0.0225 (13)0.0000.0106 (10)0.000
Mn20.0285 (11)0.0301 (12)0.0220 (10)0.0067 (8)0.0095 (9)0.0012 (8)
Ag10.0211 (9)0.0406 (11)0.0244 (9)0.0000.0065 (7)0.000
Ag20.0458 (16)0.0151 (12)0.0175 (12)0.0011 (9)0.0010 (10)0.0004 (8)
O10.013 (4)0.025 (5)0.051 (6)0.002 (4)0.009 (4)0.014 (4)
O20.020 (4)0.022 (4)0.011 (4)0.006 (3)0.002 (3)0.008 (3)
O30.025 (5)0.027 (5)0.027 (5)0.007 (4)0.011 (4)0.007 (4)
O40.026 (5)0.022 (4)0.010 (4)0.008 (4)0.004 (3)0.006 (3)
O50.028 (5)0.038 (5)0.019 (4)0.007 (4)0.010 (4)0.001 (4)
O60.050 (7)0.026 (5)0.032 (5)0.015 (5)0.007 (5)0.015 (4)
Geometric parameters (Å, º) top
As1—O11.680 (9)Mn2—O3vi2.038 (9)
As1—O51.688 (9)Mn2—O4vii2.076 (8)
As1—O41.693 (8)Mn2—O5iv2.098 (9)
As1—O31.703 (9)Mn2—O2iv2.121 (9)
As2—O61.682 (10)Mn2—O52.198 (10)
As2—O6i1.682 (10)Ag1—O3viii2.451 (9)
As2—O2i1.688 (7)Ag1—O32.451 (9)
As2—O21.688 (7)Ag1—O3ix2.569 (9)
Mn1—O2ii2.226 (9)Ag1—O3x2.569 (9)
Mn1—O22.226 (9)Ag2—O6i2.311 (10)
Mn1—O4i2.227 (8)Ag2—O6xi2.311 (10)
Mn1—O4iii2.227 (8)Ag2—O1xii2.342 (9)
Mn1—O1iv2.242 (9)Ag2—O1iv2.342 (9)
Mn1—O1v2.242 (9)Ag2—O1v2.595 (10)
Mn2—O62.016 (12)Ag2—O1vi2.595 (10)
O1—As1—O5108.2 (5)O4vii—Mn2—O5iv157.1 (4)
O1—As1—O4112.1 (5)O6—Mn2—O2iv167.5 (3)
O5—As1—O4108.6 (4)O3vi—Mn2—O2iv92.9 (3)
O1—As1—O3112.4 (5)O4vii—Mn2—O2iv77.0 (3)
O5—As1—O3109.6 (4)O5iv—Mn2—O2iv81.6 (3)
O4—As1—O3105.8 (4)O6—Mn2—O581.8 (4)
O6—As2—O6i100.1 (8)O3vi—Mn2—O5177.7 (4)
O6—As2—O2i107.2 (5)O4vii—Mn2—O590.7 (3)
O6i—As2—O2i115.7 (4)O5iv—Mn2—O580.1 (4)
O6—As2—O2115.7 (4)O2iv—Mn2—O587.0 (3)
O6i—As2—O2107.2 (5)O3viii—Ag1—O3176.1 (4)
O2i—As2—O2110.6 (6)O3viii—Ag1—O3ix83.9 (3)
O2ii—Mn1—O2143.9 (4)O3—Ag1—O3ix95.8 (3)
O2ii—Mn1—O4i71.9 (3)O3viii—Ag1—O3x95.8 (3)
O2—Mn1—O4i88.2 (3)O3—Ag1—O3x83.9 (3)
O2ii—Mn1—O4iii88.2 (3)O3ix—Ag1—O3x170.2 (4)
O2—Mn1—O4iii71.9 (3)O6i—Ag2—O6xi180.0 (5)
O4i—Mn1—O4iii112.8 (5)O6i—Ag2—O1xii78.8 (4)
O2ii—Mn1—O1iv117.2 (4)O6xi—Ag2—O1xii101.2 (4)
O2—Mn1—O1iv92.4 (3)O6i—Ag2—O1iv101.2 (4)
O4i—Mn1—O1iv158.5 (3)O6xi—Ag2—O1iv78.8 (4)
O4iii—Mn1—O1iv87.7 (3)O1xii—Ag2—O1iv180.0 (4)
O2ii—Mn1—O1v92.4 (3)O6i—Ag2—O1v74.8 (4)
O2—Mn1—O1v117.2 (4)O6xi—Ag2—O1v105.2 (4)
O4i—Mn1—O1v87.7 (3)O1xii—Ag2—O1v114.9 (4)
O4iii—Mn1—O1v158.5 (3)O1iv—Ag2—O1v65.1 (4)
O1iv—Mn1—O1v72.9 (5)O6i—Ag2—O1vi105.2 (4)
O6—Mn2—O3vi98.5 (4)O6xi—Ag2—O1vi74.8 (4)
O6—Mn2—O4vii108.5 (4)O1xii—Ag2—O1vi65.1 (4)
O3vi—Mn2—O4vii87.0 (4)O1iv—Ag2—O1vi114.9 (4)
O6—Mn2—O5iv91.0 (4)O1v—Ag2—O1vi180.0 (3)
O3vi—Mn2—O5iv102.2 (4)
Symmetry codes: (i) x+1, y, z+1/2; (ii) x+1, y, z1/2; (iii) x, y, z1; (iv) x+1/2, y+1/2, z; (v) x+1/2, y+1/2, z1/2; (vi) x+1/2, y1/2, z+1/2; (vii) x+1/2, y+1/2, z+1; (viii) x+1, y, z+3/2; (ix) x+1, y+1, z+1; (x) x, y+1, z+1/2; (xi) x, y, z1/2; (xii) x+1/2, y1/2, z.

Experimental details

Crystal data
Chemical formulaAg1.49Mn3(AsO4)3
Mr742.29
Crystal system, space groupMonoclinic, C2/c
Temperature (K)293
a, b, c (Å)12.262 (2), 12.934 (3), 6.707 (1)
β (°) 113.690 (2)
V3)974.1 (3)
Z4
Radiation typeMo Kα
µ (mm1)16.92
Crystal size (mm)0.44 × 0.2 × 0.03
Data collection
DiffractometerEnraf-Nonius CAD-4
diffractometer
Absorption correctionψ scan
(North et al., 1968)
Tmin, Tmax0.178, 0.309
No. of measured, independent and
observed [I > 2σ(I)] reflections
1112, 1067, 829
Rint0.071
(sin θ/λ)max1)0.639
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.052, 0.156, 1.07
No. of reflections1067
No. of parameters97
w = 1/[σ2(Fo2) + (0.0825P)2 + 48.2737P]
where P = (Fo2 + 2Fc2)/3
Δρmax, Δρmin (e Å3)2.61, 2.08

Computer programs: CAD-4 EXPRESS (Duisenberg, 1992; Macíček & Yordanov, 1992), CAD-4 EXPRESS, MolEN (Fair, 1990), SHELXS86 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), DIAMOND (Brandenburg, 1998), SHELXL97.

Selected geometric parameters (Å, º) top
As1—O11.680 (9)Mn2—O3iv2.038 (9)
As1—O51.688 (9)Mn2—O4v2.076 (8)
As1—O41.693 (8)Mn2—O5iii2.098 (9)
As1—O31.703 (9)Mn2—O2iii2.121 (9)
As2—O61.682 (10)Mn2—O52.198 (10)
As2—O2i1.688 (7)Ag1—O3vi2.451 (9)
Mn1—O2ii2.226 (9)Ag1—O3vii2.569 (9)
Mn1—O4i2.227 (8)Ag2—O6i2.311 (10)
Mn1—O1iii2.242 (9)Ag2—O1viii2.342 (9)
Mn2—O62.016 (12)Ag2—O1ix2.595 (10)
O2ii—Mn1—O2143.9 (4)O4x—Mn1—O1iii87.7 (3)
O2—Mn1—O4i88.2 (3)O2—Mn1—O1ix117.2 (4)
O2—Mn1—O4x71.9 (3)O4x—Mn1—O1ix158.5 (3)
O4i—Mn1—O4x112.8 (5)O1iii—Mn1—O1ix72.9 (5)
O2—Mn1—O1iii92.4 (3)
Symmetry codes: (i) x+1, y, z+1/2; (ii) x+1, y, z1/2; (iii) x+1/2, y+1/2, z; (iv) x+1/2, y1/2, z+1/2; (v) x+1/2, y+1/2, z+1; (vi) x+1, y, z+3/2; (vii) x+1, y+1, z+1; (viii) x+1/2, y1/2, z; (ix) x+1/2, y+1/2, z1/2; (x) x, y, z1.
 

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