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Ammonium zinc phosphate, (NH4)Zn(HPO4)(H2PO4), is built up from infinite 4-ring chains of vertex-sharing ZnO4 and (H/H2)PO4 tetrahedra [dav(Zn—O) = 1.943 (2) Å and dav(P—O) = 1.534 (2) Å] crosslinked by ammonium cations. The intra-chain O—H...O hydrogen bond appears to be essentially symmetric [d(O...O) = 2.442 (3) Å].

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801013010/bt6071sup1.cif
Contains datablocks I, nzp2

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536801013010/bt6071Isup2.hkl
Contains datablock I

Key indicators

  • Single-crystal X-ray study
  • T = 298 K
  • Mean [sigma](P-O) = 0.002 Å
  • R factor = 0.031
  • wR factor = 0.075
  • Data-to-parameter ratio = 20.7

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

General Notes

ABSTM_02 When printed, the submitted absorption T values will be replaced by the scaled T values. Since the ratio of scaled T's is identical to the ratio of reported T values, the scaling does not imply a change to the absorption corrections used in the study. Ratio of Tmax expected/reported 0.543 Tmax scaled 0.288 Tmin scaled 0.214

Comment top

The title compound complements the known ammonium zinc phosphates (NH4)Zn(HPO4)(H2PO4).H2O (Boudjada et al., 1980), (NH4)Zn2(PO4)(HPO4) (Bircsak & Harrison, 1998), (NH4)ZnPO4—ABW (Bu et al., 1997) and (NH4)ZnPO4—HEX (Xu et al., 1998). The first two phases are layered with respect to the connectivity of the tetrahedral ZnO4/PO4 building units whereas the latter two are three-dimensional and resemble related aluminosilicate zeolites (Harrison, 2000).

In the title compound (Fig. 1), ZnO4 and PO4 tetrahedral building blocks [dav(Zn—O) = 1.943 (2) Å and dav(P—O) = 1.534 (2) Å] assemble into infinite chains which propagate along [001] (Fig. 2). The chains are built up from polyhedral 4-rings with the zinc centres serving to fuse the 4-rings into chains, which results in the 1:2 Zn:P ratio. Similar zincophosphate 4-ring chains have been seen in RbZn(HPO4)(H2PO4).H2O (Harrison et al., 1997) and N2C6H14.Zn(HPO4)2.H2O (Chavez et al., 1999). In (NH4)Zn(HPO4)(H2PO4), four O atoms serve as Zn—O—P links (θav = 128.5°) and four are terminal to P. Assuming the presence of ammonium cations rather than unprecendented neutral ammonia, three H atoms are required for charge balancing. The structures of similar phases (Harrison et al., 1997; Bircsak & Harrison, 1998) indicate that they are almost certainly associated with terminal P—O bonds. In (NH4)Zn(HPO4)(H2PO4), two of these are well defined and the P1—O6 and P2—O7 bonds show their expected P—O bond lengths (Lightfoot & Masson, 1996). Both P1—O6—H6 and P2—O7—H7 partake in inter-chain hydrogen bonds (Table 2). The O6—H6···O3 interaction links adjacent chains along [010], and the O7—H7···O2 bond performs a similar function along [100]. The location of the third H atom is considerably less certain. The largest difference map feature corresponded to a region roughly half way betweeen O8 and O5i [symmetry code: (i) 1 - x, 1 - y, -z]. Inclusion of a riding H atom at this point marginally lowered the crystallographic residuals. If the H atom is really located here, this intra-chain hydrogen bond (Fig. 3) is essentially symmetric (Fillaux, 1999), although there are no symmetry constraints. However, further investigation, perhaps using neutron diffraction (Wilson, 2001) would be necessary to confirm this site.

The ammonium cation appears to participate in two strong well defined hydrogen bonds (via atoms H3 and H4) and two weaker bifurcated linkages involving H1 and H2. These N—H···O bonds serve to link the anionic [Zn(HPO4(H2PO4]- chains into a three-dimensional array.

Experimental top

The title compound was repared hydrothermally from a mixture of H3PO4, ZnO, NH4OH and TiO2. It appears that titania must be present for (NH4)Zn(HPO4)(H2PO4) to form, although its role is unknown.

Computing details top

Data collection: XSCANS (Bruker, 1997); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. Fragment of (NH4)Zn(HPO4)(H2PO4) shown with 50% probability displacement ellipsoids. The symmetry codes are as in Table 1. The N1—H4···O8 hydrogen bond is indicated by a dashed line.
[Figure 2] Fig. 2. Packing diagram for (NH4)Zn(HPO4)(H2PO4) viewed down [001] (50% displacement ellipsoids; ammonium H atoms have been omitted for clarity; atom colours are as in Fig. 1).
[Figure 3] Fig. 3. Side-on view of a zincophosphate tetrhaedral chain in (NH4)Zn(HPO4)(H2PO4) showing the proposed O8—H8···O5 intra-chain hydrogen bond as a dashed line [50% displacement ellipsoids; symmetry code: (i) 1 - x, 1 - y, -z].
(I) top
Crystal data top
(NH4)Zn(HPO4)(H2PO4)Dx = 2.347 Mg m3
Mr = 276.38Melting point: decomposes before melting K
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 7.6801 (19) ÅCell parameters from 25 reflections
b = 13.235 (3) Åθ = 5.4–12.8°
c = 8.0780 (16) ŵ = 3.56 mm1
β = 107.690 (16)°T = 298 K
V = 782.3 (3) Å3Lump, colourless
Z = 40.40 × 0.35 × 0.35 mm
F(000) = 552
Data collection top
Bruker P4
diffractometer
1911 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.023
Graphite monochromatorθmax = 30.0°, θmin = 3.1°
θ–2θ scansh = 110
Absorption correction: ψ scan
(XEMP; Bruker, 1997)
k = 118
Tmin = 0.395, Tmax = 0.530l = 1111
2957 measured reflections3 standard reflections every 97 reflections
2280 independent reflections intensity decay: none
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.031H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.075 w = 1/[σ2(Fo2) + (0.0353P)2 + 0.6283P]
where P = (Fo2 + 2Fc2)/3
S = 1.07(Δ/σ)max = 0.001
2280 reflectionsΔρmax = 0.51 e Å3
110 parametersΔρmin = 0.53 e Å3
0 restraintsExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0051 (9)
Crystal data top
(NH4)Zn(HPO4)(H2PO4)V = 782.3 (3) Å3
Mr = 276.38Z = 4
Monoclinic, P21/nMo Kα radiation
a = 7.6801 (19) ŵ = 3.56 mm1
b = 13.235 (3) ÅT = 298 K
c = 8.0780 (16) Å0.40 × 0.35 × 0.35 mm
β = 107.690 (16)°
Data collection top
Bruker P4
diffractometer
1911 reflections with I > 2σ(I)
Absorption correction: ψ scan
(XEMP; Bruker, 1997)
Rint = 0.023
Tmin = 0.395, Tmax = 0.5303 standard reflections every 97 reflections
2957 measured reflections intensity decay: none
2280 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0310 restraints
wR(F2) = 0.075H atoms treated by a mixture of independent and constrained refinement
S = 1.07Δρmax = 0.51 e Å3
2280 reflectionsΔρmin = 0.53 e Å3
110 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*/Ueq
N10.3407 (4)0.2432 (2)0.0269 (3)0.0302 (6)
H10.44590.26280.10530.036*
H20.27030.21160.08170.036*
H30.36550.20060.05000.036*
H40.28130.29770.02950.036*
Zn10.39618 (4)0.50781 (2)0.24352 (4)0.01563 (10)
P10.64019 (9)0.66311 (5)0.51298 (8)0.01533 (14)
P20.23715 (9)0.53633 (5)0.15325 (8)0.01653 (14)
O10.5889 (3)0.43346 (15)0.1905 (3)0.0255 (4)
O20.2660 (3)0.40473 (15)0.3314 (2)0.0236 (4)
O30.2350 (3)0.56646 (14)0.0283 (2)0.0205 (4)
O40.4594 (3)0.61796 (15)0.4075 (2)0.0230 (4)
O50.7699 (3)0.68645 (15)0.4079 (2)0.0228 (4)
O60.5925 (3)0.76467 (14)0.5904 (3)0.0254 (4)
H60.62120.82020.52880.030*
O70.0838 (3)0.59705 (17)0.2888 (2)0.0274 (5)
H70.03230.57700.28120.033*
O80.1993 (4)0.42287 (15)0.1748 (3)0.0335 (5)
H80.20770.37020.28490.040*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0300 (13)0.0315 (13)0.0306 (13)0.0035 (11)0.0114 (11)0.0001 (11)
Zn10.01472 (14)0.01617 (15)0.01590 (14)0.00002 (11)0.00449 (10)0.00074 (10)
P10.0166 (3)0.0136 (3)0.0156 (3)0.0017 (2)0.0048 (2)0.0000 (2)
P20.0171 (3)0.0181 (3)0.0150 (3)0.0021 (2)0.0058 (2)0.0014 (2)
O10.0192 (9)0.0269 (10)0.0343 (11)0.0048 (8)0.0140 (8)0.0027 (8)
O20.0165 (9)0.0280 (10)0.0248 (9)0.0021 (8)0.0039 (7)0.0108 (8)
O30.0249 (9)0.0214 (9)0.0150 (8)0.0087 (7)0.0059 (7)0.0017 (7)
O40.0173 (9)0.0239 (9)0.0249 (9)0.0013 (7)0.0019 (7)0.0077 (8)
O50.0267 (10)0.0232 (9)0.0227 (9)0.0033 (8)0.0139 (8)0.0001 (7)
O60.0391 (12)0.0149 (8)0.0284 (10)0.0055 (8)0.0196 (9)0.0051 (7)
O70.0170 (9)0.0406 (12)0.0217 (9)0.0001 (8)0.0017 (8)0.0120 (8)
O80.0588 (15)0.0186 (9)0.0297 (11)0.0065 (10)0.0234 (11)0.0040 (8)
Geometric parameters (Å, º) top
N1—H10.9000P1—O2i1.535 (2)
N1—H20.8999P1—O61.5720 (19)
N1—H30.9000P2—O1ii1.510 (2)
N1—H40.9000P2—O31.5251 (18)
Zn1—O41.9298 (19)P2—O81.529 (2)
Zn1—O11.9307 (19)P2—O71.564 (2)
Zn1—O21.9484 (19)O6—H60.9500
Zn1—O31.9620 (18)O7—H70.9500
P1—O41.514 (2)O8—H81.1467
P1—O51.5240 (19)
H1—N1—H2109.5O5—P1—O6108.60 (11)
H1—N1—H3109.5O2i—P1—O6106.43 (12)
H2—N1—H3109.5O1ii—P2—O3113.04 (12)
H1—N1—H4109.5O1ii—P2—O8112.73 (13)
H2—N1—H4109.5O3—P2—O8108.00 (11)
H3—N1—H4109.5O1ii—P2—O7104.37 (11)
O4—Zn1—O1119.18 (9)O3—P2—O7108.22 (11)
O4—Zn1—O2109.19 (9)O8—P2—O7110.37 (13)
O1—Zn1—O2103.70 (9)P2ii—O1—Zn1133.91 (13)
O4—Zn1—O3105.57 (8)P1i—O2—Zn1122.89 (11)
O1—Zn1—O3108.96 (8)P2—O3—Zn1124.07 (11)
O2—Zn1—O3110.14 (8)P1—O4—Zn1132.90 (12)
O4—P1—O5114.18 (11)P1—O6—H6109.5
O4—P1—O2i110.62 (11)P2—O7—H7109.5
O5—P1—O2i110.56 (11)P2—O8—H8129.2
O4—P1—O6106.05 (12)
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+1, y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O5iii0.902.442.971 (3)118
N1—H1···O10.902.513.192 (3)133
N1—H2···O4iv0.902.183.014 (3)154
N1—H2···O6i0.902.562.978 (3)109
N1—H3···O7v0.902.012.907 (3)176
N1—H4···O80.902.022.901 (3)167
O6—H6···O3vi0.951.742.603 (3)150
O7—H7···O2vii0.951.732.603 (3)151
O8—H8···O5ii1.151.302.442 (3)175
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+1, y+1, z; (iii) x+3/2, y1/2, z+1/2; (iv) x+1/2, y1/2, z+1/2; (v) x+1/2, y1/2, z1/2; (vi) x+1/2, y+3/2, z+1/2; (vii) x, y+1, z.

Experimental details

Crystal data
Chemical formula(NH4)Zn(HPO4)(H2PO4)
Mr276.38
Crystal system, space groupMonoclinic, P21/n
Temperature (K)298
a, b, c (Å)7.6801 (19), 13.235 (3), 8.0780 (16)
β (°) 107.690 (16)
V3)782.3 (3)
Z4
Radiation typeMo Kα
µ (mm1)3.56
Crystal size (mm)0.40 × 0.35 × 0.35
Data collection
DiffractometerBruker P4
diffractometer
Absorption correctionψ scan
(XEMP; Bruker, 1997)
Tmin, Tmax0.395, 0.530
No. of measured, independent and
observed [I > 2σ(I)] reflections
2957, 2280, 1911
Rint0.023
(sin θ/λ)max1)0.703
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.075, 1.07
No. of reflections2280
No. of parameters110
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.51, 0.53

Computer programs: XSCANS (Bruker, 1997), XSCANS, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), SHELXL97.

Selected geometric parameters (Å, º) top
Zn1—O41.9298 (19)P1—O2i1.535 (2)
Zn1—O11.9307 (19)P1—O61.5720 (19)
Zn1—O21.9484 (19)P2—O1ii1.510 (2)
Zn1—O31.9620 (18)P2—O31.5251 (18)
P1—O41.514 (2)P2—O81.529 (2)
P1—O51.5240 (19)P2—O71.564 (2)
O4—Zn1—O1119.18 (9)O2i—P1—O6106.43 (12)
O4—Zn1—O2109.19 (9)O1ii—P2—O3113.04 (12)
O1—Zn1—O2103.70 (9)O1ii—P2—O8112.73 (13)
O4—Zn1—O3105.57 (8)O3—P2—O8108.00 (11)
O1—Zn1—O3108.96 (8)O1ii—P2—O7104.37 (11)
O2—Zn1—O3110.14 (8)O3—P2—O7108.22 (11)
O4—P1—O5114.18 (11)O8—P2—O7110.37 (13)
O4—P1—O2i110.62 (11)P2ii—O1—Zn1133.91 (13)
O5—P1—O2i110.56 (11)P1i—O2—Zn1122.89 (11)
O4—P1—O6106.05 (12)P2—O3—Zn1124.07 (11)
O5—P1—O6108.60 (11)P1—O4—Zn1132.90 (12)
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+1, y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O5iii0.902.442.971 (3)118.3
N1—H1···O10.902.513.192 (3)132.5
N1—H2···O4iv0.902.183.014 (3)154.1
N1—H2···O6i0.902.562.978 (3)109.4
N1—H3···O7v0.902.012.907 (3)175.7
N1—H4···O80.902.022.901 (3)166.7
O6—H6···O3vi0.951.742.603 (3)150.0
O7—H7···O2vii0.951.732.603 (3)150.7
O8—H8···O5ii1.151.302.442 (3)175.4
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+1, y+1, z; (iii) x+3/2, y1/2, z+1/2; (iv) x+1/2, y1/2, z+1/2; (v) x+1/2, y1/2, z1/2; (vi) x+1/2, y+3/2, z+1/2; (vii) x, y+1, z.
 

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