Crystal structure of dimanganese(II) zinc bis­[ortho­phosphate(V)] monohydrate

In contrast to most other structures of transition metal orthophosphates with composition M_3-xM'_x(PO₄)₂·H₂O, the three metallic sites in the structure of Mn₂Zn(PO₄)₂·H₂O show no statistical disorder.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](P-O) = 0.002 Å
• R factor = 0.019
• wR factor = 0.052
• Data-to-parameter ratio = 19.0

checkCIF/PLATON results

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Alert level B
PLAT430_ALERT_2_B Short Inter D...A Contact  O1     ..  O1      ..       2.62 Ang.
PLAT430_ALERT_2_B Short Inter D...A Contact  O4     ..  O6      ..       2.79 Ang.

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CRYSC01_ALERT_1_C The word below has not been recognised as a standard
            identifier.
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Alert level G
PLAT004_ALERT_5_G Polymeric Structure Found with Dimension .......          3 Info
PLAT005_ALERT_5_G No _iucr_refine_instructions_details  in the CIF     Please Do !
PLAT007_ALERT_5_G Number of Unrefined Donor-H Atoms ..............          2 Report
PLAT042_ALERT_1_G Calc. and Reported MoietyFormula Strings  Differ     Please Check
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Zn1    --  O5      ..       12.2 su
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Zn1    --  O1_b    ..        6.0 su
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Mn1    --  O6_e    ..        6.4 su
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Mn1    --  O9_f    ..       10.2 su
PLAT793_ALERT_4_G The Model has Chirality at P1      .............          R Verify
PLAT793_ALERT_4_G The Model has Chirality at P2      .............          R Verify
PLAT899_ALERT_4_G SHELXL97   is Deprecated and Succeeded by SHELXL       2014 Note
PLAT961_ALERT_5_G Dataset Contains no Negative Intensities .......     Please Check

   0 ALERT level A = Most likely a serious problem - resolve or explain
   2 ALERT level B = A potentially serious problem, consider carefully
   1 ALERT level C = Check. Ensure it is not caused by an omission or oversight
  12 ALERT level G = General information/check it is not something unexpected

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   6 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion
   4 ALERT type 5 Informative message, check

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S1. Chemical context

The great structural diversity of metal-based phosphates, associated with their physical properties makes this family of compounds inter­esting as potential functional materials, e.g. as catalysts (Viter & Nagornyi, 2009; Weng et al., 2009) or ion-exchangers (Jignasa et al., 2006). Among the wide variety of metal phosphates, one of our inter­ests is focused on mixed metallic orthophosphates of general formula M_3-xM'_x(PO₄)₂·H₂O. The present communication reports the hydro­thermal synthesis and structural characterization of a new member of this family, Mn₂Zn(PO₄)₂·H₂O.

S2. Structural commentary

The structure of the title compound is built up from four different types of building units: [MnO₆] and [MnO₅(H₂O)] o­cta­hedra, [ZnO₅] square pyramids and PO₄ tetra­hedra, as shown in Fig. 1. Whereas the [MnO₆] o­cta­hedron is more or less regular with Mn—O distances in the range 2.1254 (13) to 2.2590 (13) Å, the [MnO₅(H₂O)] o­cta­hedron is significantly distorted with five equal Mn—O distances in the range 2.1191 (13) to 2.1556 (16) and one considerably longer Mn—O distance to the water ligand of 2.5163 (15) Å; the ZnO₅ square pyramid is also distorted with four shorter Zn—O distances between 1.9546 (13) and 2.0347 (12) Å and one longer Zn—O distance, likewise to the water O atom [2.3093 (14) Å]; the two PO₄ tetra­hedra are rather regular [P—O distances between 1.5322 (13) and 1.5570 (13) Å; O—P—O angles between 102.92 (7) and 111.62 (8)°]. These polyhedra are arranged in such a way as to build up two types of layers parallel to (101). One layer contains two [ZnO₅] polyhedra linked together by edge-sharing into a [Zn₂O₈] dimer that in turn is linked to PO₄ tetra­hedra. The other layer contains dimers of the type [Mn₂O₈(H₂O)₂] (also formed by edge-sharing of two [MnO₅(H₂O)] o­cta­hedra), connecting [MnO₆] o­cta­hedra and PO₄ tetra­hedra through common vertices. The two types of layers are linked by common edges and vertices into a framework structure with channels parallel to [101]. The water molecules of the [MnO₅(H₂O)] o­cta­hedra protrude into these channels and develop hydrogen bonds (one bifurcated) of medium-to-weak strength to framework O atoms across the channels (Fig 2; Table 1).

The title compound adopts the Fe₃(PO₄)₂·H₂O structure type (Moore & Araki, 1975) and is isotypic with various structures of general formula M_3-xM'_x(PO₄)₂·H₂O: CuMn₂(PO₄)₂·H₂O (Liao et al., 1995); Co_2.59Zn_0.41(PO₄)₂·H₂O (Sørensen et al., 2005); Co_2.39Cu_0.61(PO₄)₂·H₂O (Assani et al., 2010); Mg_1.65Cu_1.35(PO₄)₂·H₂O (Khmiyas et al. 2015).

S3. Synthesis and crystallization

Crystals of Mn₂Zn(PO₄)₂·H₂O were obtained by hydro­thermal treatment of of zinc oxide (0.0406 g), metallic manganese (0.0824 g), phospho­ric acid (0.1 ml) and 12.5 ml of distilled water, in a proportion corresponding to the molar ratio Zn: Mn: P = 1: 3: 3. The hydro­thermal reaction was conducted in a 23 ml Teflon-lined autoclave under autogenous pressure at 493 K for five days. After being filtered, washed with deionized water and dried in air, the reaction product consisted of two types of crystals, the first as off-white parallelepipeds corresponding to Mn₇(PO₄)₂(HPO₄)₄ (Riou et al., 1987) and the second as colourless parallelepipeds corresponding to the title compound.

S4. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The O-bound H atoms were initially located in a difference map. In the last refinement cycle the distances were fixed at 0.89 and 0.91 Å, respectively, and the H atoms refined in the riding-model approximation with U_iso(H) set to 1.5U_eq(O). The highest peak and the deepest hole in the final Fourier map are at 0.32 Å and 0.30 Å, respectively, from Mn1 and Zn1.

Related literature

For related literature, see: Assani et al. (2010); Jignasa et al. (2006); Khmiyas et al. (2015); Liao et al. (1995); Moore & Araki (1975); Riou et al. (1987); Sørensen et al. (2005); Viter & Nagornyi (2009); Weng et al. (2009).

Computing details

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); 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, 2012) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

Fig. 1. The principal building units in the structure of Mn2Zn(PO4)2·H2O. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen bonds are indicated by dashed lines. [Symmetry codes: (i) -x + 1, -y + 1, -z + 1; (ii) x + 1/2, -y + 1/2, z + 1/2; (iii) -x + 2, -y + 1, -z + 1; (iv) -x + 3/2, y + 1/2, -z + 1/2; (v) -x + 1/2, y - 1/2, -z + 1/2; (vi) x - 1/2, -y + 1/2, z - 1/2; (vii) x - 1/2, -y + 3/2, z - 1/2; (viii) -x + 1/2, y + 1/2, -z + 1/2.]

Fig. 2. Polyhedral representation of Mn2Zn(PO4)2·H2O showing channels extending parallel to [101]. Hydrogen bonds are shown as dashed lines.

Dimanganese(II) zinc bis[orthophosphate(V)] monohydrate

Crystal data

Mn2Zn(PO4)2·H2O	F(000) = 736
Mr = 383.21	Dx = 3.688 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2407 reflections
a = 8.1784 (2) Å	θ = 2.8–32.0°
b = 10.1741 (2) Å	µ = 7.54 mm^−1
c = 9.0896 (2) Å	T = 296 K
β = 114.142 (1)°	Parallelepiped, off-white
V = 690.17 (3) Å^3	0.32 × 0.27 × 0.19 mm
Z = 4

Data collection

Bruker X8 APEX diffractometer	2407 independent reflections
Radiation source: fine-focus sealed tube	2305 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
ϕ and ω scans	θmax = 32.0°, θmin = 2.8°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −12→12
Tmin = 0.574, Tmax = 0.748	k = −14→15
11327 measured reflections	l = −13→13

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.019	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.052	H-atom parameters constrained
S = 1.11	w = 1/[σ^2(Fo^2) + (0.0248P)^2 + 1.0141P] where P = (Fo^2 + 2Fc^2)/3
2407 reflections	(Δ/σ)max = 0.001
127 parameters	Δρmax = 0.94 e Å^−3
0 restraints	Δρmin = −0.84 e Å^−3

Special details

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 > 2σ(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 (Ų)

	x	y	z	Uiso*/Ueq
Mn1	0.88638 (3)	0.35884 (3)	0.46580 (3)	0.00768 (6)
Mn2	0.48057 (3)	0.38305 (3)	0.21880 (3)	0.00726 (6)
Zn1	0.12609 (3)	0.62028 (2)	0.06179 (2)	0.00934 (6)
P1	0.70438 (5)	0.08456 (4)	0.32706 (5)	0.00553 (8)
P2	0.38560 (5)	0.67442 (4)	0.36388 (5)	0.00613 (8)
O1	0.58212 (17)	0.03301 (13)	0.40831 (15)	0.0102 (2)
O2	0.87050 (16)	0.15076 (13)	0.45546 (15)	0.0094 (2)
O3	0.59293 (17)	0.18429 (12)	0.19887 (15)	0.0092 (2)
O4	0.76145 (17)	−0.03217 (12)	0.25178 (15)	0.0092 (2)
O5	0.23736 (18)	0.77279 (13)	0.26723 (16)	0.0123 (2)
O6	0.36400 (17)	0.63194 (13)	0.51688 (15)	0.0104 (2)
O7	0.57269 (16)	0.73311 (13)	0.41028 (15)	0.0110 (2)
O8	0.35411 (17)	0.55914 (13)	0.24330 (15)	0.0107 (2)
O9	0.88135 (18)	0.58568 (14)	0.57419 (16)	0.0130 (2)
H1	0.7876	0.6203	0.4923	0.019*
H2	0.8793	0.5969	0.6731	0.019*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mn1	0.00519 (11)	0.00776 (11)	0.00860 (11)	−0.00070 (8)	0.00129 (8)	0.00274 (8)
Mn2	0.00657 (11)	0.00704 (11)	0.00777 (11)	−0.00016 (8)	0.00254 (9)	−0.00025 (8)
Zn1	0.00839 (10)	0.00949 (10)	0.00884 (9)	0.00028 (6)	0.00219 (7)	0.00093 (6)
P1	0.00538 (16)	0.00594 (17)	0.00519 (16)	0.00046 (13)	0.00209 (13)	−0.00030 (13)
P2	0.00556 (16)	0.00676 (17)	0.00569 (16)	0.00008 (13)	0.00193 (13)	−0.00044 (13)
O1	0.0107 (5)	0.0111 (5)	0.0126 (5)	0.0015 (4)	0.0087 (5)	0.0025 (4)
O2	0.0079 (5)	0.0105 (5)	0.0073 (5)	−0.0020 (4)	0.0008 (4)	−0.0025 (4)
O3	0.0099 (5)	0.0080 (5)	0.0081 (5)	0.0022 (4)	0.0020 (4)	0.0013 (4)
O4	0.0083 (5)	0.0091 (5)	0.0099 (5)	0.0017 (4)	0.0033 (4)	−0.0027 (4)
O5	0.0121 (5)	0.0135 (6)	0.0108 (5)	0.0070 (5)	0.0041 (4)	0.0035 (4)
O6	0.0106 (5)	0.0137 (6)	0.0071 (5)	−0.0006 (4)	0.0038 (4)	0.0016 (4)
O7	0.0081 (5)	0.0129 (6)	0.0120 (5)	−0.0031 (4)	0.0041 (4)	−0.0030 (4)
O8	0.0107 (5)	0.0093 (5)	0.0099 (5)	0.0011 (4)	0.0021 (4)	−0.0035 (4)
O9	0.0109 (5)	0.0181 (6)	0.0106 (5)	0.0020 (5)	0.0051 (4)	0.0007 (5)

Geometric parameters (Å, º)

Mn1—O6^i	2.1191 (13)	Zn1—O1^vi	2.0242 (13)
Mn1—O2	2.1208 (14)	Zn1—O1^viii	2.0347 (12)
Mn1—O3^ii	2.1464 (12)	Zn1—O5	2.3093 (14)
Mn1—O9^iii	2.1504 (14)	P1—O3	1.5327 (13)
Mn1—O4^iv	2.1556 (13)	P1—O4	1.5355 (13)
Mn1—O9	2.5163 (15)	P1—O2	1.5377 (13)
Mn2—O8	2.1254 (13)	P1—O1	1.5570 (13)
Mn2—O5^v	2.1533 (13)	P2—O7	1.5322 (13)
Mn2—O4^iv	2.1921 (13)	P2—O6	1.5340 (13)
Mn2—O2^vi	2.2126 (13)	P2—O5	1.5401 (13)
Mn2—O6^i	2.2166 (13)	P2—O8	1.5532 (13)
Mn2—O3	2.2590 (13)	O9—H1	0.8939
Zn1—O7^vii	1.9546 (13)	O9—H2	0.9131
Zn1—O8	2.0174 (13)
O6^i—Mn1—O2	90.23 (5)	O4^iv—Mn2—O3	87.66 (5)
O6^i—Mn1—O3^ii	109.27 (5)	O2^vi—Mn2—O3	76.87 (5)
O2—Mn1—O3^ii	81.31 (5)	O6^i—Mn2—O3	87.34 (5)
O6^i—Mn1—O9^iii	161.48 (5)	O7^vii—Zn1—O8	132.60 (5)
O2—Mn1—O9^iii	107.27 (5)	O7^vii—Zn1—O1^vi	100.19 (6)
O3^ii—Mn1—O9^iii	80.06 (5)	O8—Zn1—O1^vi	99.81 (5)
O6^i—Mn1—O4^iv	81.32 (5)	O7^vii—Zn1—O1^viii	117.98 (5)
O2—Mn1—O4^iv	118.14 (5)	O8—Zn1—O1^viii	107.48 (5)
O3^ii—Mn1—O4^iv	158.49 (5)	O1^vi—Zn1—O1^viii	80.41 (5)
O9^iii—Mn1—O4^iv	84.99 (5)	O7^vii—Zn1—O5	87.57 (5)
O6^i—Mn1—O9	76.07 (5)	O8—Zn1—O5	67.61 (5)
O2—Mn1—O9	157.28 (5)	O1^vi—Zn1—O5	167.20 (5)
O3^ii—Mn1—O9	86.18 (5)	O1^viii—Zn1—O5	105.05 (5)
O9^iii—Mn1—O9	89.00 (5)	O3—P1—O4	111.58 (7)
O4^iv—Mn1—O9	78.15 (5)	O3—P1—O2	110.68 (7)
O8—Mn2—O5^v	89.03 (5)	O4—P1—O2	109.99 (7)
O8—Mn2—O4^iv	98.10 (5)	O3—P1—O1	106.62 (7)
O5^v—Mn2—O4^iv	167.53 (5)	O4—P1—O1	108.79 (7)
O8—Mn2—O2^vi	104.14 (5)	O2—P1—O1	109.08 (7)
O5^v—Mn2—O2^vi	90.14 (5)	O7—P2—O6	109.42 (7)
O4^iv—Mn2—O2^vi	97.96 (5)	O7—P2—O5	111.62 (8)
O8—Mn2—O6^i	91.85 (5)	O6—P2—O5	110.15 (7)
O5^v—Mn2—O6^i	91.25 (5)	O7—P2—O8	110.32 (7)
O4^iv—Mn2—O6^i	78.36 (5)	O6—P2—O8	112.31 (8)
O2^vi—Mn2—O6^i	163.97 (5)	O5—P2—O8	102.92 (7)
O8—Mn2—O3	173.90 (5)	H1—O9—H2	114.6
O5^v—Mn2—O3	84.95 (5)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x+1/2, −y+1/2, z+1/2; (iii) −x+2, −y+1, −z+1; (iv) −x+3/2, y+1/2, −z+1/2; (v) −x+1/2, y−1/2, −z+1/2; (vi) x−1/2, −y+1/2, z−1/2; (vii) x−1/2, −y+3/2, z−1/2; (viii) −x+1/2, y+1/2, −z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O9—H1···O7	0.89	1.97	2.7866 (19)	151
O9—H2···O5^ix	0.91	2.16	2.8687 (19)	134
O9—H2···O1^ii	0.91	2.48	3.0494 (19)	120

Symmetry codes: (ii) x+1/2, −y+1/2, z+1/2; (ix) x+1/2, −y+3/2, z+1/2.