Silver molybdyl arsenate has been synthesized by a solid-state reaction. The structure consists of AsO4 tetrahedra and MoO6 octahedra sharing corners to form a three-dimensional framwork containing channels running along [010], in which the Ag+ ions are located. Structural relationships between the different monoarsenates of the AMoO2AsO4 series (A = Ag, Li, Na, K and Rb) are discussed.
Supporting information
Key indicators
- Single-crystal X-ray study
- T = 298 K
- Mean (As-O) = 0.005 Å
- R factor = 0.032
- wR factor = 0.097
- Data-to-parameter ratio = 13.4
checkCIF/PLATON results
No syntax errors found
Alert level C
PLAT241_ALERT_2_C Check High Ueq as Compared to Neighbors for Ag
PLAT301_ALERT_3_C Main Residue Disorder ......................... 9.00 Perc.
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
2 ALERT level C = Check and explain
0 ALERT level G = General alerts; check
0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
1 ALERT type 2 Indicator that the structure model may be wrong or deficient
1 ALERT type 3 Indicator that the structure quality may be low
0 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: CAD-4 EXPRESS (Duisenberg, 1992; Macíček & Yordanov, 1992); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97.
Silver molybdyl arsenate
top
Crystal data top
AgMoO2AsO4 | F(000) = 680 |
Mr = 374.73 | Dx = 5.201 Mg m−3 |
Orthorhombic, Pnma | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2n | Cell parameters from 25 reflections |
a = 10.241 (1) Å | θ = 10–16° |
b = 6.587 (1) Å | µ = 13.52 mm−1 |
c = 7.095 (1) Å | T = 298 K |
V = 478.61 (11) Å3 | Prism, yellow |
Z = 4 | 0.20 × 0.15 × 0.10 mm |
Data collection top
Enraf-Nonius CAD-4 diffractometer | 724 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.035 |
Graphite monochromator | θmax = 30.0°, θmin = 3.5° |
ω/2θ scans | h = −1→14 |
Absorption correction: ψ scan (North et al., 1968) | k = −9→3 |
Tmin = 0.108, Tmax = 0.264 | l = −1→9 |
1278 measured reflections | 2 standard reflections every 120 min |
753 independent reflections | intensity decay: none |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.032 | w = 1/[σ2(Fo2) + (0.038P)2 + 5.3764P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.097 | (Δ/σ)max < 0.001 |
S = 1.24 | Δρmax = 1.08 e Å−3 |
753 reflections | Δρmin = −1.54 e Å−3 |
56 parameters | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.075 (4) |
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 | x | y | z | Uiso*/Ueq | Occ. (<1) |
As | 0.1596 (1) | 0.2500 | 0.0332 (1) | 0.0065 (2) | |
Mo | 0.3312 (1) | 0.2500 | 0.4490 (1) | 0.0071 (2) | |
Ag | 0.0059 (1) | 0.5197 (3) | 0.4486 (2) | 0.0400 (4) | 0.50 |
O1 | 0.3983 (5) | 0.2500 | 0.6681 (7) | 0.0178 (11) | |
O2 | 0.1681 (5) | 0.2500 | 0.5013 (8) | 0.0167 (11) | |
O3 | 0.3030 (5) | 0.2500 | 0.1468 (7) | 0.0106 (9) | |
O4 | 0.0282 (5) | 0.2500 | 0.1747 (7) | 0.0143 (10) | |
O5 | 0.3429 (4) | 0.5444 (6) | 0.3900 (5) | 0.0135 (7) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
As | 0.0070 (4) | 0.0064 (4) | 0.0062 (4) | 0.000 | −0.0008 (2) | 0.000 |
Mo | 0.0077 (3) | 0.0080 (3) | 0.0056 (3) | 0.000 | 0.0001 (2) | 0.000 |
Ag | 0.0331 (6) | 0.0360 (8) | 0.0510 (9) | 0.0163 (5) | 0.0041 (6) | −0.0034 (7) |
O1 | 0.018 (2) | 0.027 (3) | 0.008 (2) | 0.000 | −0.001 (2) | 0.000 |
O2 | 0.012 (2) | 0.025 (3) | 0.014 (2) | 0.000 | 0.001 (2) | 0.000 |
O3 | 0.008 (2) | 0.016 (2) | 0.007 (2) | 0.000 | −0.002 (2) | 0.000 |
O4 | 0.009 (2) | 0.025 (3) | 0.009 (2) | 0.000 | 0.002 (2) | 0.000 |
O5 | 0.022 (2) | 0.008 (2) | 0.011 (2) | 0.001 (1) | 0.001 (1) | −0.003 (1) |
Geometric parameters (Å, º) top
As—O3 | 1.676 (5) | Mo—O4iv | 2.201 (5) |
As—O4 | 1.678 (5) | Ag—O2v | 2.367 (4) |
As—O5i | 1.694 (4) | Ag—O2 | 2.461 (4) |
As—O5ii | 1.694 (4) | Ag—O4 | 2.640 (4) |
Mo—O1 | 1.700 (5) | Ag—O1ii | 2.688 (4) |
Mo—O2 | 1.710 (5) | Ag—O3vi | 2.816 (4) |
Mo—O5iii | 1.987 (4) | Ag—O3vii | 2.846 (4) |
Mo—O5 | 1.987 (4) | Ag—O5vi | 2.930 (4) |
Mo—O3 | 2.163 (5) | Ag—O4v | 3.093 (4) |
| | | |
O3—As—O4 | 114.5 (3) | O5iii—Mo—O5 | 154.7 (2) |
O3—As—O5i | 107.6 (2) | O1—Mo—O3 | 163.8 (2) |
O4—As—O5i | 110.3 (2) | O2—Mo—O3 | 94.9 (2) |
O3—As—O5ii | 107.6 (2) | O5iii—Mo—O3 | 78.4 (1) |
O4—As—O5ii | 110.3 (2) | O5—Mo—O3 | 78.4 (1) |
O5i—As—O5ii | 106.2 (3) | O1—Mo—O4iv | 89.7 (2) |
O1—Mo—O2 | 101.3 (3) | O2—Mo—O4iv | 169.0 (2) |
O1—Mo—O5iii | 99.7 (1) | O5iii—Mo—O4iv | 82.0 (1) |
O2—Mo—O5iii | 96.0 (1) | O5—Mo—O4iv | 82.0 (1) |
O1—Mo—O5 | 99.7 (1) | O3—Mo—O4iv | 74.2 (2) |
O2—Mo—O5 | 96.0 (1) | | |
Symmetry codes: (i) −x+1/2, y−1/2, z−1/2; (ii) −x+1/2, −y+1, z−1/2; (iii) x, −y+1/2, z; (iv) x+1/2, y, −z+1/2; (v) −x, −y+1, −z+1; (vi) x−1/2, y, −z+1/2; (vii) −x+1/2, −y+1, z+1/2. |