The structure of diammonium tetramolybdate, [(NH
4)
2(Mo
4O
13)]
n, consists of puckered layers built up from the self-assembly of chains of tetrameric units [Mo
4O
13]
2− linked through corner-sharing octahedra. The ammonium cations are located between consecutive layers, yielding a three-dimensional array
via extensive N—H
O hydrogen bonding, in which terminal oxo groups of the surface network are involved.
Supporting information
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (Mo-O) = 0.005 Å
- H-atom completeness 1%
- R factor = 0.037
- wR factor = 0.104
- Data-to-parameter ratio = 11.4
checkCIF/PLATON results
No syntax errors found
Alert level B
PLAT027_ALERT_3_B _diffrn_reflns_theta_full (too) Low ............ 24.99 Deg.
PLAT430_ALERT_2_B Short Inter D...A Contact O1 .. N1 = 2.87 Ang.
PLAT430_ALERT_2_B Short Inter D...A Contact O3 .. N1 = 2.81 Ang.
PLAT430_ALERT_2_B Short Inter D...A Contact O9 .. N2 = 2.86 Ang.
PLAT430_ALERT_2_B Short Inter D...A Contact O10 .. N1 = 2.80 Ang.
PLAT430_ALERT_2_B Short Inter D...A Contact O10 .. N2 = 2.85 Ang.
PLAT430_ALERT_2_B Short Inter D...A Contact O13 .. N1 = 2.87 Ang.
Alert level C
CHEMW03_ALERT_2_C The ratio of given/expected molecular weight as
calculated from the _atom_site* data lies outside
the range 0.99 <> 1.01
From the CIF: _cell_formula_units_Z 8
From the CIF: _chemical_formula_weight 627.84
TEST: Calculate formula weight from _atom_site_*
atom mass num sum
N 14.01 2.00 28.01
O 16.00 13.00 207.99
H 1.01 0.00 0.00
Mo 95.94 4.00 383.76
Calculated formula weight 619.76
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings Differ .... ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ?
PLAT043_ALERT_1_C Check Reported Molecular Weight ................ 627.84
PLAT044_ALERT_1_C Calculated and Reported Dx Differ .............. ?
PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)... ?
PLAT430_ALERT_2_C Short Inter D...A Contact O9 .. N2 = 2.90 Ang.
Alert level G
FORMU01_ALERT_1_G There is a discrepancy between the atom counts in the
_chemical_formula_sum and _chemical_formula_moiety. This is
usually due to the moiety formula being in the wrong format.
Atom count from _chemical_formula_sum: H8 Mo4 N2 O13
Atom count from _chemical_formula_moiety:H8260 N20
FORMU01_ALERT_2_G There is a discrepancy between the atom counts in the
_chemical_formula_sum and the formula from the _atom_site* data.
Atom count from _chemical_formula_sum:H8 Mo4 N2 O13
Atom count from the _atom_site data: Mo4 N2 O13
CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected.
CELLZ01_ALERT_1_G WARNING: H atoms missing from atom site list. Is this intentional?
From the CIF: _cell_formula_units_Z 8
From the CIF: _chemical_formula_sum H8 Mo4 N2 O13
TEST: Compare cell contents of formula and atom_site data
atom Z*formula cif sites diff
H 64.00 0.00 64.00
Mo 32.00 32.00 0.00
N 16.00 16.00 0.00
O 104.00 104.00 0.00
0 ALERT level A = In general: serious problem
7 ALERT level B = Potentially serious problem
7 ALERT level C = Check and explain
4 ALERT level G = General alerts; check
8 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
9 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: MSC/AFC Diffractometer Control Software (Molecular
Structure Corporation, 1993); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 1999); program(s) used to solve structure: SHELXLTL-NT (Bruker, 1998); program(s) used to refine structure: SHELXLTL-NT; molecular graphics: SHELXLTL-NT; software used to prepare material for publication: SHELXLTL-NT.
Crystal data top
(NH4)2[Mo4O13] | F(000) = 2352 |
Mr = 627.84 | Dx = 3.724 Mg m−3 |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2ab | Cell parameters from 25 reflections |
a = 15.423 (2) Å | θ = 39.3–39.8° |
b = 19.0022 (9) Å | µ = 4.45 mm−1 |
c = 7.6423 (7) Å | T = 293 K |
V = 2239.7 (4) Å3 | Prism, colorless |
Z = 8 | 0.60 × 0.36 × 0.20 mm |
Data collection top
Rigaku AFC-7S diffractometer | 1842 reflections with I > 2σ(I) |
Radiation source: Normal-focus sealed tube | Rint = 0.039 |
Graphite monochromator | θmax = 25.0°, θmin = 2.1° |
ω–2θ scans | h = 0→18 |
Absorption correction: empirical (using intensity measurements) (Walker & Stuart 1983) | k = −2→22 |
Tmin = 0.160, Tmax = 0.411 | l = 0→9 |
2166 measured reflections | 3 standard reflections every 150 reflections |
1968 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)] = 0.037 | H-atom parameters not refined |
wR(F2) = 0.104 | w = 1/[σ2(Fo2) + (0.0611P)2 + 14.763P] where P = (Fo2 + 2Fc2)/3 |
S = 1.24 | (Δ/σ)max < 0.001 |
1968 reflections | Δρmax = 1.40 e Å−3 |
172 parameters | Δρmin = −2.81 e Å−3 |
0 restraints | |
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 | |
Mo1 | −0.14025 (4) | 0.39902 (3) | −0.20935 (8) | 0.00648 (19) | |
Mo2 | −0.27954 (4) | 0.24880 (3) | −0.42271 (7) | 0.00456 (19) | |
Mo3 | 0.06614 (3) | 0.38978 (3) | −0.11479 (8) | 0.00570 (19) | |
Mo4 | −0.07082 (4) | 0.24360 (3) | −0.32982 (8) | 0.00402 (19) | |
O1 | −0.1263 (3) | 0.4551 (3) | −0.3854 (7) | 0.0164 (11) | |
O2 | −0.0231 (3) | 0.3315 (2) | −0.2804 (6) | 0.0083 (10) | |
O3 | −0.3448 (3) | 0.1779 (3) | −0.4433 (7) | 0.0135 (11) | |
O4 | −0.1683 (3) | 0.1949 (2) | −0.4297 (6) | 0.0071 (9) | |
O5 | 0.1438 (3) | 0.3173 (2) | −0.1721 (6) | 0.0083 (10) | |
O6 | −0.1802 (3) | 0.3141 (2) | −0.3107 (6) | 0.0066 (9) | |
O7 | −0.0519 (3) | 0.4218 (2) | −0.0502 (6) | 0.0090 (10) | |
O8 | −0.2723 (3) | 0.2819 (2) | −0.6337 (6) | 0.0090 (10) | |
O9 | −0.2294 (3) | 0.4311 (3) | −0.1039 (7) | 0.0128 (11) | |
O10 | 0.1187 (3) | 0.4228 (3) | 0.0658 (7) | 0.0141 (11) | |
O11 | 0.0854 (3) | 0.4519 (3) | −0.2742 (7) | 0.0131 (10) | |
O12 | 0.0127 (3) | 0.1959 (2) | −0.4253 (6) | 0.0093 (10) | |
O13 | −0.0754 (3) | 0.2086 (3) | −0.1201 (7) | 0.0091 (10) | |
N1 | 0.0226 (4) | 0.4195 (3) | 0.3765 (8) | 0.0146 (13) | |
N2 | 0.2840 (5) | 0.4322 (3) | 0.2305 (9) | 0.0218 (15) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Mo1 | 0.0055 (3) | 0.0041 (3) | 0.0098 (3) | 0.0005 (2) | −0.0016 (2) | −0.0019 (2) |
Mo2 | 0.0036 (3) | 0.0050 (3) | 0.0051 (3) | −0.0001 (2) | −0.0003 (2) | −0.0006 (2) |
Mo3 | 0.0046 (3) | 0.0045 (3) | 0.0080 (3) | −0.0005 (2) | −0.0006 (2) | 0.0000 (2) |
Mo4 | 0.0036 (3) | 0.0032 (3) | 0.0052 (3) | 0.0007 (2) | −0.0002 (2) | −0.0007 (2) |
O1 | 0.016 (3) | 0.019 (3) | 0.015 (3) | −0.004 (2) | −0.001 (2) | 0.003 (2) |
O2 | 0.006 (2) | 0.012 (2) | 0.007 (2) | −0.0012 (19) | −0.0011 (18) | −0.0028 (18) |
O3 | 0.013 (2) | 0.012 (3) | 0.015 (3) | −0.005 (2) | −0.002 (2) | −0.002 (2) |
O4 | 0.007 (2) | 0.005 (2) | 0.009 (2) | −0.0024 (19) | −0.0022 (18) | 0.0011 (18) |
O5 | 0.008 (2) | 0.007 (2) | 0.010 (2) | 0.0035 (19) | 0.0000 (18) | 0.0022 (19) |
O6 | 0.004 (2) | 0.005 (2) | 0.011 (2) | −0.0014 (18) | −0.0008 (18) | 0.0007 (18) |
O7 | 0.006 (2) | 0.009 (2) | 0.012 (2) | −0.0001 (19) | −0.0018 (19) | −0.0032 (19) |
O8 | 0.008 (2) | 0.012 (2) | 0.007 (2) | 0.0012 (19) | −0.0019 (18) | 0.001 (2) |
O9 | 0.010 (2) | 0.009 (2) | 0.019 (3) | 0.0044 (19) | 0.001 (2) | 0.001 (2) |
O10 | 0.013 (2) | 0.014 (3) | 0.015 (3) | −0.001 (2) | −0.002 (2) | −0.003 (2) |
O11 | 0.012 (2) | 0.012 (2) | 0.015 (3) | −0.004 (2) | 0.003 (2) | 0.005 (2) |
O12 | 0.008 (2) | 0.008 (2) | 0.012 (2) | 0.0013 (19) | 0.0021 (19) | −0.0012 (19) |
O13 | 0.010 (2) | 0.008 (2) | 0.009 (2) | 0.0044 (19) | −0.0008 (19) | 0.001 (2) |
N1 | 0.015 (3) | 0.011 (3) | 0.017 (3) | 0.003 (3) | 0.004 (3) | −0.004 (3) |
N2 | 0.024 (4) | 0.021 (4) | 0.020 (3) | −0.002 (3) | −0.006 (3) | 0.007 (3) |
Geometric parameters (Å, º) top
Mo1—O9 | 1.706 (5) | Mo3—O7 | 1.982 (5) |
Mo1—O1 | 1.730 (5) | Mo3—O2 | 2.173 (5) |
Mo1—O7 | 1.877 (5) | Mo3—O12ii | 2.330 (5) |
Mo1—O6 | 1.893 (5) | Mo4—O12 | 1.735 (5) |
Mo1—O2 | 2.281 (5) | Mo4—O13 | 1.736 (5) |
Mo2—O3 | 1.688 (5) | Mo4—O2 | 1.865 (5) |
Mo2—O8 | 1.734 (5) | Mo4—O4 | 1.923 (4) |
Mo2—O5i | 1.902 (5) | Mo4—O6 | 2.158 (5) |
Mo2—O4 | 1.999 (5) | Mo4—O13iii | 2.398 (5) |
Mo2—O6 | 2.149 (5) | O5—Mo2iv | 1.902 (5) |
Mo2—O8ii | 2.288 (5) | O8—Mo2iii | 2.288 (5) |
Mo3—O10 | 1.719 (5) | O12—Mo3iii | 2.330 (5) |
Mo3—O11 | 1.723 (5) | O13—Mo4ii | 2.398 (5) |
Mo3—O5 | 1.877 (5) | | |
| | | |
O9—Mo1—O1 | 104.3 (2) | O7—Mo3—O2 | 73.73 (18) |
O9—Mo1—O7 | 101.3 (2) | O10—Mo3—O12ii | 85.6 (2) |
O1—Mo1—O7 | 105.7 (2) | O11—Mo3—O12ii | 168.5 (2) |
O9—Mo1—O6 | 103.7 (2) | O5—Mo3—O12ii | 81.81 (19) |
O1—Mo1—O6 | 104.3 (2) | O7—Mo3—O12ii | 74.64 (18) |
O7—Mo1—O6 | 134.3 (2) | O2—Mo3—O12ii | 77.41 (17) |
O9—Mo1—O2 | 162.1 (2) | O12—Mo4—O13 | 102.6 (2) |
O1—Mo1—O2 | 93.6 (2) | O12—Mo4—O2 | 105.1 (2) |
O7—Mo1—O2 | 73.09 (18) | O13—Mo4—O2 | 99.9 (2) |
O6—Mo1—O2 | 71.39 (18) | O12—Mo4—O4 | 99.3 (2) |
O3—Mo2—O8 | 104.0 (2) | O13—Mo4—O4 | 98.6 (2) |
O3—Mo2—O5i | 102.2 (2) | O2—Mo4—O4 | 145.1 (2) |
O8—Mo2—O5i | 98.4 (2) | O12—Mo4—O6 | 158.8 (2) |
O3—Mo2—O4 | 95.8 (2) | O13—Mo4—O6 | 98.2 (2) |
O8—Mo2—O4 | 96.1 (2) | O2—Mo4—O6 | 74.86 (18) |
O5i—Mo2—O4 | 153.45 (19) | O4—Mo4—O6 | 73.42 (18) |
O3—Mo2—O6 | 157.3 (2) | O12—Mo4—O13iii | 80.2 (2) |
O8—Mo2—O6 | 96.6 (2) | O13—Mo4—O13iii | 176.0 (3) |
O5i—Mo2—O6 | 84.10 (18) | O2—Mo4—O13iii | 81.93 (18) |
O4—Mo2—O6 | 72.18 (18) | O4—Mo4—O13iii | 77.99 (18) |
O3—Mo2—O8ii | 85.2 (2) | O6—Mo4—O13iii | 78.74 (17) |
O8—Mo2—O8ii | 170.8 (2) | Mo4—O2—Mo3 | 145.5 (3) |
O5i—Mo2—O8ii | 80.63 (19) | Mo4—O2—Mo1 | 103.8 (2) |
O4—Mo2—O8ii | 81.55 (18) | Mo3—O2—Mo1 | 94.40 (18) |
O6—Mo2—O8ii | 74.22 (17) | Mo4—O4—Mo2 | 114.4 (2) |
O10—Mo3—O11 | 103.7 (2) | Mo3—O5—Mo2iv | 144.1 (3) |
O10—Mo3—O5 | 98.9 (2) | Mo1—O6—Mo2 | 152.5 (3) |
O11—Mo3—O5 | 103.2 (2) | Mo1—O6—Mo4 | 107.6 (2) |
O10—Mo3—O7 | 97.0 (2) | Mo2—O6—Mo4 | 99.92 (18) |
O11—Mo3—O7 | 97.1 (2) | Mo1—O7—Mo3 | 115.7 (2) |
O5—Mo3—O7 | 150.4 (2) | Mo2—O8—Mo2iii | 143.3 (3) |
O10—Mo3—O2 | 162.2 (2) | Mo4—O12—Mo3iii | 152.7 (3) |
O11—Mo3—O2 | 92.7 (2) | Mo4—O13—Mo4ii | 135.0 (3) |
O5—Mo3—O2 | 83.93 (19) | | |
Symmetry codes: (i) x−1/2, y, −z−1/2; (ii) x, −y+1/2, z+1/2; (iii) x, −y+1/2, z−1/2; (iv) x+1/2, y, −z−1/2. |