The structure of the hydrothermally synthesized compound AgCo3PO4(HPO4)2, silver tricobalt phosphate bis(hydrogen phosphate), consists of edge-sharing CoO6 chains linked together by the phosphate groups and hydrogen bonds. The three-dimensional framework delimits two types of tunnels which accommodate Ag+ cations and OH groups. The title compound is isostructural with the compounds AM3H2(XO4)3 (A = Na or Ag, M = Co or Mn, and X = P or As) of the alluaudite structure type.
Supporting information
Single crystals of AgCo3PO4(HPO4)2 were prepared hydrothermally from an
aqueous solution of AgNO3 (Fluka, 99%), Co(NO3)2·6H2O (Fluka,
99%) and H3PO4 (Prolabo, 85%, density 1.70 Mg m-3), with the atomic
ratio Ag:Co:P = 2:1:2. The mixture was filled in a glass tube to about
25% in volume. The tube was sealed and heated to 573 K for 3 d. Normal cooling
to room temperature produced pink parallelepiped crystals of
AgCo3PO4(HPO4)2.
The position of the H atom was obtained by difference techniques and the O6—H
bond length was restrained to 0.80 Å by the DFIX option in
SHELXL97 (Sheldrick, 1997). BUT s.u. given in Table 2 - please clarify.
Data collection: CAD-4 EXPRESS (Duisenberg, 1992; Macíček & Yordanov, 1992); cell refinement: CAD-4 EXPRESS; data reduction: MolEN (Fair, 1990); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97.
Silver tricobalt phosphate bis(hydrogen phosphate)
top
Crystal data top
AgCo3PO4(HPO4)2 | F(000) = 1084 |
Mr = 571.59 | Dx = 4.320 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71069 Å |
a = 12.035 (2) Å | Cell parameters from 25 reflections |
b = 12.235 (2) Å | θ = 10.8–13.8° |
c = 6.541 (2) Å | µ = 8.38 mm−1 |
β = 114.14 (2)° | T = 293 K |
V = 878.9 (3) Å3 | Parallelepiped, pink |
Z = 4 | 0.43 × 0.18 × 0.14 mm |
Data collection top
Enraf-Nonius CAD4 diffractometer | 932 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.013 |
Graphite monochromator | θmax = 27.0°, θmin = 2.5° |
ω/2θ scans | h = −14→15 |
Absorption correction: ψ-scan (North et al., 1968) | k = −15→0 |
Tmin = 0.178, Tmax = 0.309 | l = −8→0 |
1048 measured reflections | 2 standard reflections every 120 min |
961 independent reflections | intensity decay: 0.4% |
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)] = 0.025 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.068 | w = 1/[σ2(Fo2) + (0.0351P)2 + 5.6691P] where P = (Fo2 + 2Fc2)/3 |
S = 1.22 | (Δ/σ)max < 0.001 |
961 reflections | Δρmax = 0.97 e Å−3 |
92 parameters | Δρmin = −1.46 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0184 (7) |
Crystal data top
AgCo3PO4(HPO4)2 | V = 878.9 (3) Å3 |
Mr = 571.59 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 12.035 (2) Å | µ = 8.38 mm−1 |
b = 12.235 (2) Å | T = 293 K |
c = 6.541 (2) Å | 0.43 × 0.18 × 0.14 mm |
β = 114.14 (2)° | |
Data collection top
Enraf-Nonius CAD4 diffractometer | 932 reflections with I > 2σ(I) |
Absorption correction: ψ-scan (North et al., 1968) | Rint = 0.013 |
Tmin = 0.178, Tmax = 0.309 | 2 standard reflections every 120 min |
1048 measured reflections | intensity decay: 0.4% |
961 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.025 | 0 restraints |
wR(F2) = 0.068 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.22 | Δρmax = 0.97 e Å−3 |
961 reflections | Δρmin = −1.46 e Å−3 |
92 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 | |
Ag | 0.0000 | 0.47148 (4) | 0.2500 | 0.02258 (19) | |
Co1 | 0.29015 (4) | 0.16196 (4) | 0.37801 (8) | 0.00841 (18) | |
Co2 | 0.5000 | 0.27873 (5) | 0.2500 | 0.0094 (2) | |
P1 | 0.22255 (8) | 0.38696 (7) | 0.11416 (14) | 0.0072 (2) | |
P2 | 0.0000 | 0.18372 (10) | 0.2500 | 0.0073 (3) | |
O1 | 0.1068 (2) | 0.1078 (2) | 0.2663 (4) | 0.0108 (5) | |
O2 | 0.0350 (2) | 0.2557 (2) | 0.4620 (4) | 0.0092 (5) | |
O3 | 0.3443 (2) | 0.1719 (2) | 0.1121 (4) | 0.0093 (5) | |
O4 | 0.2169 (2) | 0.31838 (19) | 0.3066 (4) | 0.0090 (5) | |
O5 | 0.1628 (2) | 0.4994 (2) | 0.1069 (4) | 0.0111 (5) | |
O6 | 0.3605 (2) | 0.4057 (2) | 0.1588 (4) | 0.0105 (5) | |
H | 0.384 (6) | 0.467 (2) | 0.193 (12) | 0.050* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Ag | 0.0098 (2) | 0.0393 (3) | 0.0152 (3) | 0.000 | 0.00155 (18) | 0.000 |
Co1 | 0.0084 (3) | 0.0060 (3) | 0.0109 (3) | 0.00012 (16) | 0.0040 (2) | 0.00024 (16) |
Co2 | 0.0086 (3) | 0.0086 (3) | 0.0109 (3) | 0.000 | 0.0040 (3) | 0.000 |
P1 | 0.0076 (4) | 0.0046 (4) | 0.0088 (4) | −0.0001 (3) | 0.0027 (3) | −0.0003 (3) |
P2 | 0.0057 (5) | 0.0058 (5) | 0.0086 (6) | 0.000 | 0.0011 (4) | 0.000 |
O1 | 0.0081 (11) | 0.0069 (11) | 0.0171 (13) | 0.0008 (9) | 0.0048 (10) | −0.0009 (9) |
O2 | 0.0072 (11) | 0.0098 (11) | 0.0092 (11) | −0.0010 (9) | 0.0020 (9) | −0.0010 (9) |
O3 | 0.0092 (11) | 0.0093 (11) | 0.0083 (11) | −0.0014 (9) | 0.0025 (9) | −0.0006 (8) |
O4 | 0.0100 (11) | 0.0076 (11) | 0.0097 (11) | 0.0002 (9) | 0.0045 (9) | 0.0006 (9) |
O5 | 0.0100 (11) | 0.0057 (10) | 0.0168 (13) | 0.0012 (9) | 0.0045 (10) | 0.0005 (9) |
O6 | 0.0078 (11) | 0.0067 (11) | 0.0160 (12) | −0.0015 (9) | 0.0039 (9) | −0.0008 (9) |
Geometric parameters (Å, º) top
Ag—O5i | 2.382 (3) | Co2—O3 | 2.156 (2) |
Ag—O5ii | 2.382 (3) | Co2—O3vii | 2.156 (2) |
Ag—O5 | 2.516 (3) | Co2—O6vii | 2.184 (3) |
Ag—O5iii | 2.516 (3) | Co2—O6 | 2.184 (3) |
Co1—O5iv | 2.059 (3) | P1—O4 | 1.537 (2) |
Co1—O4 | 2.079 (2) | P1—O3viii | 1.543 (3) |
Co1—O3 | 2.096 (3) | P1—O5 | 1.544 (3) |
Co1—O4v | 2.113 (2) | P1—O6 | 1.581 (3) |
Co1—O1 | 2.126 (2) | P2—O2 | 1.549 (3) |
Co1—O2v | 2.176 (2) | P2—O2iii | 1.549 (3) |
Co2—O2v | 2.134 (2) | P2—O1iii | 1.554 (2) |
Co2—O2vi | 2.134 (2) | P2—O1 | 1.554 (2) |
| | | |
O5i—Ag—O5ii | 162.80 (12) | O2v—Co2—O3vii | 87.85 (9) |
O5i—Ag—O5 | 83.73 (8) | O2vi—Co2—O3vii | 78.36 (9) |
O5ii—Ag—O5 | 93.94 (8) | O3—Co2—O3vii | 105.36 (13) |
O5i—Ag—O5iii | 93.94 (8) | O2v—Co2—O6vii | 107.85 (10) |
O5ii—Ag—O5iii | 83.73 (8) | O2vi—Co2—O6vii | 88.53 (10) |
O5—Ag—O5iii | 164.39 (12) | O3—Co2—O6vii | 170.02 (9) |
O5iv—Co1—O4 | 169.42 (10) | O3vii—Co2—O6vii | 82.99 (9) |
O5iv—Co1—O3 | 85.57 (10) | O2v—Co2—O6 | 88.53 (10) |
O4—Co1—O3 | 90.43 (10) | O2vi—Co2—O6 | 107.85 (10) |
O5iv—Co1—O4v | 100.56 (10) | O3—Co2—O6 | 82.99 (9) |
O4—Co1—O4v | 86.10 (10) | O3vii—Co2—O6 | 170.02 (9) |
O3—Co1—O4v | 162.56 (10) | O6vii—Co2—O6 | 89.27 (13) |
O5iv—Co1—O1 | 86.66 (10) | O4—P1—O3viii | 110.50 (14) |
O4—Co1—O1 | 85.68 (9) | O4—P1—O5 | 109.60 (14) |
O3—Co1—O1 | 111.36 (10) | O3viii—P1—O5 | 109.41 (14) |
O4v—Co1—O1 | 85.45 (10) | O4—P1—O6 | 108.84 (14) |
O5iv—Co1—O2v | 103.38 (10) | O3viii—P1—O6 | 109.97 (14) |
O4—Co1—O2v | 85.38 (10) | O5—P1—O6 | 108.49 (14) |
O3—Co1—O2v | 78.72 (10) | O2—P2—O2iii | 110.7 (2) |
O4v—Co1—O2v | 83.96 (9) | O2—P2—O1iii | 108.41 (13) |
O1—Co1—O2v | 166.57 (10) | O2iii—P2—O1iii | 111.33 (13) |
O2v—Co2—O2vi | 157.24 (14) | O2—P2—O1 | 111.33 (13) |
O2v—Co2—O3 | 78.36 (9) | O2iii—P2—O1 | 108.41 (13) |
O2vi—Co2—O3 | 87.85 (9) | O1iii—P2—O1 | 106.59 (19) |
Symmetry codes: (i) x, −y+1, z+1/2; (ii) −x, −y+1, −z; (iii) −x, y, −z+1/2; (iv) −x+1/2, y−1/2, −z+1/2; (v) −x+1/2, −y+1/2, −z+1; (vi) x+1/2, −y+1/2, z−1/2; (vii) −x+1, y, −z+1/2; (viii) −x+1/2, −y+1/2, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O6—H···O1ix | 0.80 (3) | 1.74 (3) | 2.520 (3) | 164 (8) |
Symmetry code: (ix) −x+1/2, y+1/2, −z+1/2. |
Experimental details
Crystal data |
Chemical formula | AgCo3PO4(HPO4)2 |
Mr | 571.59 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 293 |
a, b, c (Å) | 12.035 (2), 12.235 (2), 6.541 (2) |
β (°) | 114.14 (2) |
V (Å3) | 878.9 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 8.38 |
Crystal size (mm) | 0.43 × 0.18 × 0.14 |
|
Data collection |
Diffractometer | Enraf-Nonius CAD4 diffractometer |
Absorption correction | ψ-scan (North et al., 1968) |
Tmin, Tmax | 0.178, 0.309 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1048, 961, 932 |
Rint | 0.013 |
(sin θ/λ)max (Å−1) | 0.638 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.025, 0.068, 1.22 |
No. of reflections | 961 |
No. of parameters | 92 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.97, −1.46 |
Selected bond lengths (Å) topAg—O5i | 2.382 (3) | Co2—O3 | 2.156 (2) |
Ag—O5ii | 2.382 (3) | Co2—O3vii | 2.156 (2) |
Ag—O5 | 2.516 (3) | Co2—O6vii | 2.184 (3) |
Ag—O5iii | 2.516 (3) | Co2—O6 | 2.184 (3) |
Co1—O5iv | 2.059 (3) | P1—O4 | 1.537 (2) |
Co1—O4 | 2.079 (2) | P1—O3viii | 1.543 (3) |
Co1—O3 | 2.096 (3) | P1—O5 | 1.544 (3) |
Co1—O4v | 2.113 (2) | P1—O6 | 1.581 (3) |
Co1—O1 | 2.126 (2) | P2—O2 | 1.549 (3) |
Co1—O2v | 2.176 (2) | P2—O2iii | 1.549 (3) |
Co2—O2v | 2.134 (2) | P2—O1iii | 1.554 (2) |
Co2—O2vi | 2.134 (2) | P2—O1 | 1.554 (2) |
Symmetry codes: (i) x, −y+1, z+1/2; (ii) −x, −y+1, −z; (iii) −x, y, −z+1/2; (iv) −x+1/2, y−1/2, −z+1/2; (v) −x+1/2, −y+1/2, −z+1; (vi) x+1/2, −y+1/2, z−1/2; (vii) −x+1, y, −z+1/2; (viii) −x+1/2, −y+1/2, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O6—H···O1ix | 0.80 (3) | 1.74 (3) | 2.520 (3) | 164 (8) |
Symmetry code: (ix) −x+1/2, y+1/2, −z+1/2. |
The A—Co—X—O systems (A is a monovalent cation and X is P or As) have been investigated as part of a search for new materials which can exhibit interesting properties in relation to their structures (magnetism, ion exchange, ionic conductivity, etc.) In recent studies of the Na—Co—P—O system, we described the structure of Na2Co(H2PO4)4·4H2O synthesized at room temperature (Guesmi et al., 2000). In the present study, we have investigated the Ag—Co—P—O system by the hydrothermal method and we obtained the title compound, the structure of which is presented here.
AgCo3PO4(HPO4)2 crystallizes in the monoclinic space group C2/c and is isostructural with the AM3H2(XO4)3-type compounds (A is Na or Ag, M is a metal and X is P or As) of the alluaudite structure type (Keller et al., 1981; Lii & Shih, 1994; Leroux et al., 1995). The P and Co atoms are surrounded by four and six O atoms, respectively. The mean distances are Co1—O 2.108, Co2—O 2.158, P1—O 1.551 and P2—O 1.552 Å, and these are in the same range as in the isostructural cobalt compounds; the longer distances, P1—O and Co2—O, involve the O atom of the OH group. The bond valence sums of the Ag, Co and P atoms are in good agreement with their oxidation states (Brese & O'Keeffe, 1985).
The structure consists of infinite chains of edge-sharing CoO6 octahedra running along [101] and having a Co1—Co1—Co2 period. These chains are linked together by the phosphate groups to form polyhedral sheets parallel to the (101) plane (Fig. 1). Each P2O4 tetrahedron shares its four vertices with two chains of the same sheet. Adjacent sheets are interconnected by the tricoordinate O5 vertex common to two Co1O6 octahedra and the HP1O4 tetrahedron.
The three-dimensional framework delimits two types of hexagonal tunnels running along the c direction, at 0,0,z and 1/2,0,z (Fig. 2). The OH groups, pointing into one type of tunnel, are involved in strong hydrogen bonds (Brown, 1976). Square plane coordinated Ag+ cations are located in the second type of tunnel. The same coordination for this cation is found in the homologous arsenates (Keller et al., 1981).