Ammonium zinc phosphate, (NH
4)Zn(HPO
4)(H
2PO
4), is built up from infinite 4-ring chains of vertex-sharing ZnO
4 and (H/H
2)PO
4 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
Key indicators
- Single-crystal X-ray study
- T = 298 K
- Mean (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
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.
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.
Crystal data top
(NH4)Zn(HPO4)(H2PO4) | Dx = 2.347 Mg m−3 |
Mr = 276.38 | Melting point: decomposes before melting K |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 7.6801 (19) Å | Cell parameters from 25 reflections |
b = 13.235 (3) Å | θ = 5.4–12.8° |
c = 8.0780 (16) Å | µ = 3.56 mm−1 |
β = 107.690 (16)° | T = 298 K |
V = 782.3 (3) Å3 | Lump, colourless |
Z = 4 | 0.40 × 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 tube | Rint = 0.023 |
Graphite monochromator | θmax = 30.0°, θmin = 3.1° |
θ–2θ scans | h = −1→10 |
Absorption correction: ψ scan (XEMP; Bruker, 1997) | k = −1→18 |
Tmin = 0.395, Tmax = 0.530 | l = −11→11 |
2957 measured reflections | 3 standard reflections every 97 reflections |
2280 independent reflections | intensity decay: none |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.031 | H 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 reflections | Δρmax = 0.51 e Å−3 |
110 parameters | Δρmin = −0.53 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0051 (9) |
Crystal data top
(NH4)Zn(HPO4)(H2PO4) | V = 782.3 (3) Å3 |
Mr = 276.38 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 7.6801 (19) Å | µ = 3.56 mm−1 |
b = 13.235 (3) Å | T = 298 K |
c = 8.0780 (16) Å | 0.40 × 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 = 0.530 | 3 standard reflections every 97 reflections |
2957 measured reflections | intensity decay: none |
2280 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.031 | 0 restraints |
wR(F2) = 0.075 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | Δρmax = 0.51 e Å−3 |
2280 reflections | Δρmin = −0.53 e Å−3 |
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 | x | y | z | Uiso*/Ueq | |
N1 | 0.3407 (4) | 0.2432 (2) | 0.0269 (3) | 0.0302 (6) | |
H1 | 0.4459 | 0.2628 | 0.1053 | 0.036* | |
H2 | 0.2703 | 0.2116 | 0.0817 | 0.036* | |
H3 | 0.3655 | 0.2006 | −0.0500 | 0.036* | |
H4 | 0.2813 | 0.2977 | −0.0295 | 0.036* | |
Zn1 | 0.39618 (4) | 0.50781 (2) | 0.24352 (4) | 0.01563 (10) | |
P1 | 0.64019 (9) | 0.66311 (5) | 0.51298 (8) | 0.01533 (14) | |
P2 | 0.23715 (9) | 0.53633 (5) | −0.15325 (8) | 0.01653 (14) | |
O1 | 0.5889 (3) | 0.43346 (15) | 0.1905 (3) | 0.0255 (4) | |
O2 | 0.2660 (3) | 0.40473 (15) | 0.3314 (2) | 0.0236 (4) | |
O3 | 0.2350 (3) | 0.56646 (14) | 0.0283 (2) | 0.0205 (4) | |
O4 | 0.4594 (3) | 0.61796 (15) | 0.4075 (2) | 0.0230 (4) | |
O5 | 0.7699 (3) | 0.68645 (15) | 0.4079 (2) | 0.0228 (4) | |
O6 | 0.5925 (3) | 0.76467 (14) | 0.5904 (3) | 0.0254 (4) | |
H6 | 0.6212 | 0.8202 | 0.5288 | 0.030* | |
O7 | 0.0838 (3) | 0.59705 (17) | −0.2888 (2) | 0.0274 (5) | |
H7 | −0.0323 | 0.5770 | −0.2812 | 0.033* | |
O8 | 0.1993 (4) | 0.42287 (15) | −0.1748 (3) | 0.0335 (5) | |
H8 | 0.2077 | 0.3702 | −0.2849 | 0.040* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0300 (13) | 0.0315 (13) | 0.0306 (13) | 0.0035 (11) | 0.0114 (11) | 0.0001 (11) |
Zn1 | 0.01472 (14) | 0.01617 (15) | 0.01590 (14) | 0.00002 (11) | 0.00449 (10) | 0.00074 (10) |
P1 | 0.0166 (3) | 0.0136 (3) | 0.0156 (3) | −0.0017 (2) | 0.0048 (2) | 0.0000 (2) |
P2 | 0.0171 (3) | 0.0181 (3) | 0.0150 (3) | 0.0021 (2) | 0.0058 (2) | 0.0014 (2) |
O1 | 0.0192 (9) | 0.0269 (10) | 0.0343 (11) | 0.0048 (8) | 0.0140 (8) | 0.0027 (8) |
O2 | 0.0165 (9) | 0.0280 (10) | 0.0248 (9) | −0.0021 (8) | 0.0039 (7) | 0.0108 (8) |
O3 | 0.0249 (9) | 0.0214 (9) | 0.0150 (8) | 0.0087 (7) | 0.0059 (7) | 0.0017 (7) |
O4 | 0.0173 (9) | 0.0239 (9) | 0.0249 (9) | −0.0013 (7) | 0.0019 (7) | −0.0077 (8) |
O5 | 0.0267 (10) | 0.0232 (9) | 0.0227 (9) | −0.0033 (8) | 0.0139 (8) | 0.0001 (7) |
O6 | 0.0391 (12) | 0.0149 (8) | 0.0284 (10) | −0.0055 (8) | 0.0196 (9) | −0.0051 (7) |
O7 | 0.0170 (9) | 0.0406 (12) | 0.0217 (9) | 0.0001 (8) | 0.0017 (8) | 0.0120 (8) |
O8 | 0.0588 (15) | 0.0186 (9) | 0.0297 (11) | −0.0065 (10) | 0.0234 (11) | −0.0040 (8) |
Geometric parameters (Å, º) top
N1—H1 | 0.9000 | P1—O2i | 1.535 (2) |
N1—H2 | 0.8999 | P1—O6 | 1.5720 (19) |
N1—H3 | 0.9000 | P2—O1ii | 1.510 (2) |
N1—H4 | 0.9000 | P2—O3 | 1.5251 (18) |
Zn1—O4 | 1.9298 (19) | P2—O8 | 1.529 (2) |
Zn1—O1 | 1.9307 (19) | P2—O7 | 1.564 (2) |
Zn1—O2 | 1.9484 (19) | O6—H6 | 0.9500 |
Zn1—O3 | 1.9620 (18) | O7—H7 | 0.9500 |
P1—O4 | 1.514 (2) | O8—H8 | 1.1467 |
P1—O5 | 1.5240 (19) | | |
| | | |
H1—N1—H2 | 109.5 | O5—P1—O6 | 108.60 (11) |
H1—N1—H3 | 109.5 | O2i—P1—O6 | 106.43 (12) |
H2—N1—H3 | 109.5 | O1ii—P2—O3 | 113.04 (12) |
H1—N1—H4 | 109.5 | O1ii—P2—O8 | 112.73 (13) |
H2—N1—H4 | 109.5 | O3—P2—O8 | 108.00 (11) |
H3—N1—H4 | 109.5 | O1ii—P2—O7 | 104.37 (11) |
O4—Zn1—O1 | 119.18 (9) | O3—P2—O7 | 108.22 (11) |
O4—Zn1—O2 | 109.19 (9) | O8—P2—O7 | 110.37 (13) |
O1—Zn1—O2 | 103.70 (9) | P2ii—O1—Zn1 | 133.91 (13) |
O4—Zn1—O3 | 105.57 (8) | P1i—O2—Zn1 | 122.89 (11) |
O1—Zn1—O3 | 108.96 (8) | P2—O3—Zn1 | 124.07 (11) |
O2—Zn1—O3 | 110.14 (8) | P1—O4—Zn1 | 132.90 (12) |
O4—P1—O5 | 114.18 (11) | P1—O6—H6 | 109.5 |
O4—P1—O2i | 110.62 (11) | P2—O7—H7 | 109.5 |
O5—P1—O2i | 110.56 (11) | P2—O8—H8 | 129.2 |
O4—P1—O6 | 106.05 (12) | | |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+1, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O5iii | 0.90 | 2.44 | 2.971 (3) | 118 |
N1—H1···O1 | 0.90 | 2.51 | 3.192 (3) | 133 |
N1—H2···O4iv | 0.90 | 2.18 | 3.014 (3) | 154 |
N1—H2···O6i | 0.90 | 2.56 | 2.978 (3) | 109 |
N1—H3···O7v | 0.90 | 2.01 | 2.907 (3) | 176 |
N1—H4···O8 | 0.90 | 2.02 | 2.901 (3) | 167 |
O6—H6···O3vi | 0.95 | 1.74 | 2.603 (3) | 150 |
O7—H7···O2vii | 0.95 | 1.73 | 2.603 (3) | 151 |
O8—H8···O5ii | 1.15 | 1.30 | 2.442 (3) | 175 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+1, −z; (iii) −x+3/2, y−1/2, −z+1/2; (iv) −x+1/2, y−1/2, −z+1/2; (v) −x+1/2, y−1/2, −z−1/2; (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) |
Mr | 276.38 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 298 |
a, b, c (Å) | 7.6801 (19), 13.235 (3), 8.0780 (16) |
β (°) | 107.690 (16) |
V (Å3) | 782.3 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 3.56 |
Crystal size (mm) | 0.40 × 0.35 × 0.35 |
|
Data collection |
Diffractometer | Bruker P4 diffractometer |
Absorption correction | ψ scan (XEMP; Bruker, 1997) |
Tmin, Tmax | 0.395, 0.530 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2957, 2280, 1911 |
Rint | 0.023 |
(sin θ/λ)max (Å−1) | 0.703 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.031, 0.075, 1.07 |
No. of reflections | 2280 |
No. of parameters | 110 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.51, −0.53 |
Selected geometric parameters (Å, º) topZn1—O4 | 1.9298 (19) | P1—O2i | 1.535 (2) |
Zn1—O1 | 1.9307 (19) | P1—O6 | 1.5720 (19) |
Zn1—O2 | 1.9484 (19) | P2—O1ii | 1.510 (2) |
Zn1—O3 | 1.9620 (18) | P2—O3 | 1.5251 (18) |
P1—O4 | 1.514 (2) | P2—O8 | 1.529 (2) |
P1—O5 | 1.5240 (19) | P2—O7 | 1.564 (2) |
| | | |
O4—Zn1—O1 | 119.18 (9) | O2i—P1—O6 | 106.43 (12) |
O4—Zn1—O2 | 109.19 (9) | O1ii—P2—O3 | 113.04 (12) |
O1—Zn1—O2 | 103.70 (9) | O1ii—P2—O8 | 112.73 (13) |
O4—Zn1—O3 | 105.57 (8) | O3—P2—O8 | 108.00 (11) |
O1—Zn1—O3 | 108.96 (8) | O1ii—P2—O7 | 104.37 (11) |
O2—Zn1—O3 | 110.14 (8) | O3—P2—O7 | 108.22 (11) |
O4—P1—O5 | 114.18 (11) | O8—P2—O7 | 110.37 (13) |
O4—P1—O2i | 110.62 (11) | P2ii—O1—Zn1 | 133.91 (13) |
O5—P1—O2i | 110.56 (11) | P1i—O2—Zn1 | 122.89 (11) |
O4—P1—O6 | 106.05 (12) | P2—O3—Zn1 | 124.07 (11) |
O5—P1—O6 | 108.60 (11) | P1—O4—Zn1 | 132.90 (12) |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+1, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O5iii | 0.90 | 2.44 | 2.971 (3) | 118.3 |
N1—H1···O1 | 0.90 | 2.51 | 3.192 (3) | 132.5 |
N1—H2···O4iv | 0.90 | 2.18 | 3.014 (3) | 154.1 |
N1—H2···O6i | 0.90 | 2.56 | 2.978 (3) | 109.4 |
N1—H3···O7v | 0.90 | 2.01 | 2.907 (3) | 175.7 |
N1—H4···O8 | 0.90 | 2.02 | 2.901 (3) | 166.7 |
O6—H6···O3vi | 0.95 | 1.74 | 2.603 (3) | 150.0 |
O7—H7···O2vii | 0.95 | 1.73 | 2.603 (3) | 150.7 |
O8—H8···O5ii | 1.15 | 1.30 | 2.442 (3) | 175.4 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+1, −z; (iii) −x+3/2, y−1/2, −z+1/2; (iv) −x+1/2, y−1/2, −z+1/2; (v) −x+1/2, y−1/2, −z−1/2; (vi) x+1/2, −y+3/2, z+1/2; (vii) −x, −y+1, −z. |
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.