supplementary materials


Acta Cryst. (2013). E69, i26    [ doi:10.1107/S1600536813008507 ]

Pentacobalt(II) divanadium(III) tetrakis(diphosphate), Co5V2(P2O7)4

A. Bronova, R. Glaum and C. Litterscheid

Abstract top

Co5V2(P2O7)4 was crystallized by chemical vapour transport using HCl as transport agent. Its crystal structure is isotypic to that of FeII5FeIII2(P2O7)4 and can be regarded as a member of the thortveitite structure family with corrugated layers of metal-oxygen polyhedra extending parallel to (010). Significant occupational disorder between cobalt(II) and vanadium(III) is observed. Four of the five cation sites are occupied by both cobalt and vanadium. The fifth cation site (Co1) is occupied by cobalt only. Sites Co1, M3 and M4 are located on twofold axes. Sites Co1, M2, M3 and M4 show octahedral coordination by oxygen; M5 has a square-pyramidal environment.

Comment top

Equilibrium investigations in the ternary system CoO/V2O3/P2O5 revealed three new phosphates: CoII3VIII4(PO4)6, CoII3VIII2(P2O7)3, and CoII5VIII2(P2O7)4 (Litterscheid, 2009).

CoII5VIII2(P2O7)4 crystallizes in the orthorhombic space group C2221. The crystal structure is isotopic to that of FeII5FeIII2(P2O7)4 (Malaman et al., 1992). It consists of P2O7 groups and five independent polyhedra [MOn] (n = 5 or 6; Fig. 1). Four of the five cation sites are occupied by both cobalt and vanadium, two lying on a two-fold axis. The fifth cation site (Co1) is occupied by cobalt only. Sites Co1, M3 and M4 are located on two-fold axes. Sites Co1, M2, M3 and M4 show octahedral coordination by oxygen. M5 has a square-pyramidal enviroment. The metal oxygen polyhedra form corrugated layers (stacked along the b-axis). These layers are separated by P2O7 groups (Fig. 3).

The pyrophosphate groups display bridging angles (P1,O5,P3)=134.8 ° and (P2,O9,P4)=135.2 °. The displacement parameters for O5 and O9 do not exhibit any anomalies. The pyrophosphate group (P1P3O7) shows a staggered conformation while (P2P4O7) has an almost eclipsed one (Fig.2).

Allowing for disorder in the crystal structure of Co5V2(P2O7)4 led to significantly improved residuals. This refinement revealed disorder for four metal sites whereas the fifth site Co1 is fully occupied by cobalt (see table). The mean inter-atomic distances d(M-O) for the sites with mixed metal occupancy range from 2.01 Å to 2.17 Å. The average distance d(M-O) = 2.15 Å is found for [Co1O6]. All distances d(M-O) are in agreement with those already known from other cobalt(II) (Krishnamachari and Calvo, 1972) and vanadium(III) (Palkina et al., 1985) phosphates.

The crystal structure of CoII5VIII2(P2O7)4 shows close similarity to the thortveitite structure family (Gossner & Mussgnug, 1929; Cruickshank et al., 1962; Zachariasen et al., 1930). This relation is visualized in Fig. 4 by comparison of the structures of CoII5VIII2(P2O7)4 and Mn2P2O7 (Stefanidis et al., 1984). With respect to the composition of the latter pyrophosphate 5/8 of the Mn2+ sites are occupied by Co2+, 2/8 by V3+ and 1/8 remains empty for charge balance. In contrast to the honeycomb network of [MnO6] octahedra (Fig. 4) in Mn2P2O7 the polyhedra [MOn] in CoII5VIII2(P2O7)4 show lower connectivity. This follows from the presence of octahedral voids and the reduced coordination number for polyhedron [M5O5].

Related literature top

For related structures, see: Cruickshank et al. (1962); Gossner & Mussgnug (1929); Krishnamachari & Calvo (1972); Litterscheid (2009); Malaman et al. (1992); Palkina et al. (1985); Stefanidis & Nord (1984); Zachariasen (1930). For the preparation, see: Binnewies et al. (2012); Litterscheid (2009).

Experimental top

For the synthesis of CoII5VIII2(P2O7)4 a pellet was prepared of thoroughly ground V4(P2O7)3 (82.97 mg) and Co2P2O7 (166.99 mg). This pellet was transferred into a silica tube and sealed under vacuum. Heating at 1173 K for three days led to a single phase product. Pink single-crystals of Co5V2(P2O7)4 were obtained by chemical vapour transport (Binnewies et al., 2012) in a temperature gradient 1273 1173 K for seven days using HCl as transport agent. HCl was obtained by in situ reaction of NH4Cl (2.7 mg) and PtCl2 (19.9 mg). In agreement with chemical vapour transport of other phosphates by HCl(g) as transport agent, we suggest the following transport reaction:

Co5V2(P2O7)4(s) + 16 HCl(g) = 5 CoCl2(g) + VCl2(g) + VCl4(g) + 2 P4O10(g) + 8 H2O(g)

Refinement top

Cobalt/vanadium disorder has been refined assuming full occupancy of metal sites M1 to M5. To maintain charge balance the refinement was constrained to a total of 20 Co2+ and 8 V3+ in the unit cell. The refinement indicated no disorder for site M1, for which in the final refinement cycles full occupancy by cobalt was assumed. Displacement parameters for sites with mixed occupancy Co/V were constrained to be identical for Co2+ and V3+. No hint on racemic twinning was observed.

Even after several hundred refinement cycles the occupancy ratio Co:V for site M2 showed a rather large value of 0.01 for the ratio shift/esd. Since there are no other hints on hidden problems with the crystal structure we think that this indicator just reflects the problems generally encountered when refining occupancy factors for atoms of similar atomic number. Actually, it was quite unexpected that the refinement of the mixed occupancies Co/V proceeded without further problems.

Computing details top

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-RED (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2008); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures top
[Figure 1] Fig. 1. ORTEP style representation of metal-oxygen coordination polyhedra in Co5V2(P2O7)4. M1: Co, M2: Co0.45V0.55, M3: Co0.86V0.14, M4: Co0.69V0.31, M5: Co0.77V0.23. Ellipsoids at 50% probability level.
[Figure 2] Fig. 2. ORTEP style representation of the pyrophosphate groups. Ellipsoids at 50% probability level.
[Figure 3] Fig. 3. Projection along the a axis of the crystal structure of Co5V2(P2O7)4 with schematic coordination polyhedra. M1: Co, M2: Co0.45V0.55, M3: Co0.86V0.14, M4: Co0.69V0.31, M5: Co0.77V0.23.
[Figure 4] Fig. 4. Comparison of the metal-oxygen co-ordination polyhedra and of their linkage in the crystal structures of Co5V2(P2O7)4 and Mn2P2O7. The same colour scheme as in Fig. 3 has been used.
Pentacobalt(II) divanadium(III) tetrakis(diphosphate) top
Crystal data top
Co5V2(P2O7)4F(000) = 2100
Mr = 1092.29Dx = 3.75 Mg m3
Orthorhombic, C2221Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2c 2Cell parameters from 4330 reflections
a = 8.3551 (4) Åθ = 1.0–29.1°
b = 9.7067 (5) ŵ = 5.92 mm1
c = 23.8555 (11) ÅT = 293 K
V = 1934.69 (16) Å3Isometric, pink
Z = 40.08 × 0.08 × 0.08 mm
Data collection top
Stoe IPDS 2T 2-circle goniometer
diffractometer
3800 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus2832 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.082
profile data from θ/2θ scansθmax = 34.1°, θmin = 3.6°
Absorption correction: multi-scan
(Blessing, 1995)
h = 1212
Tmin = 0.495, Tmax = 0.647k = 1315
9445 measured reflectionsl = 2835
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: full w = 1/[σ2(Fo2) + (0.0575P)2]
where P = (Fo2 + 2Fc2)/3
R[F2 > 2σ(F2)] = 0.046(Δ/σ)max = 0.058
wR(F2) = 0.110Δρmax = 1.02 e Å3
S = 0.92Δρmin = 1.17 e Å3
3800 reflectionsExtinction correction: SHELXL97 (Sheldrick, 2008)
201 parametersExtinction coefficient: 0.00114 (15)
1 restraintAbsolute structure: Flack (1983), 2275 Friedel pairs
Primary atom site location: structure-invariant direct methodsFlack parameter: 0.02 (2)
Crystal data top
Co5V2(P2O7)4V = 1934.69 (16) Å3
Mr = 1092.29Z = 4
Orthorhombic, C2221Mo Kα radiation
a = 8.3551 (4) ŵ = 5.92 mm1
b = 9.7067 (5) ÅT = 293 K
c = 23.8555 (11) Å0.08 × 0.08 × 0.08 mm
Data collection top
Stoe IPDS 2T 2-circle goniometer
diffractometer
3800 independent reflections
Absorption correction: multi-scan
(Blessing, 1995)
2832 reflections with I > 2σ(I)
Tmin = 0.495, Tmax = 0.647Rint = 0.082
9445 measured reflectionsθmax = 34.1°
Refinement top
R[F2 > 2σ(F2)] = 0.0461 restraint
wR(F2) = 0.110Δρmax = 1.02 e Å3
S = 0.92Δρmin = 1.17 e Å3
3800 reflectionsAbsolute structure: Flack (1983), 2275 Friedel pairs
201 parametersFlack parameter: 0.02 (2)
Special details top

Experimental. To reach the desired data resolution with the given experimental setup the image plate had been tilted by 15 degrees. This is also the explanation for the asymmetrie in the upper and lower limits of observed hkl values.

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*/UeqOcc. (<1)
Co10.08177 (13)00.50.0231 (3)
Co20.06997 (9)0.35558 (9)0.38065 (4)0.01028 (16)0.3452 (5)
V20.06997 (9)0.35558 (9)0.38065 (4)0.01028 (16)0.6548 (5)
Co30.29241 (13)00.50.0162 (3)0.934 (19)
V30.29241 (13)00.50.0162 (3)0.066 (19)
Co400.71981 (12)0.250.0106 (3)0.72 (2)
V400.71981 (12)0.250.0106 (3)0.28 (2)
Co50.31161 (9)0.36011 (9)0.35848 (4)0.0146 (2)0.827 (12)
V50.31161 (9)0.36011 (9)0.35848 (4)0.0146 (2)0.173 (12)
P10.09658 (15)0.29386 (13)0.49912 (6)0.0084 (2)
P20.11867 (16)0.05623 (14)0.37555 (6)0.0088 (3)
P30.10814 (15)0.64697 (13)0.37996 (6)0.0075 (2)
P40.23708 (16)0.46167 (13)0.23058 (6)0.0088 (2)
O10.1176 (4)0.4895 (4)0.37362 (15)0.0091 (7)
O20.1166 (5)0.2135 (4)0.37347 (17)0.0128 (7)
O30.1028 (4)0.1378 (4)0.49593 (17)0.0119 (7)
O40.1778 (5)0.5885 (4)0.25902 (18)0.0148 (8)
O50.0296 (5)0.3310 (4)0.55996 (17)0.0161 (8)
O60.2299 (4)0.5048 (4)0.40502 (16)0.0119 (7)
O70.1713 (4)0.8684 (4)0.27171 (17)0.0121 (7)
O80.0110 (5)0.7125 (4)0.33991 (17)0.0144 (8)
O90.1241 (4)0.0051 (4)0.31260 (17)0.0138 (7)
O100.0396 (4)0.3561 (4)0.46426 (16)0.0116 (7)
O110.2444 (5)0.1430 (5)0.48668 (19)0.0174 (8)
O120.4680 (4)0.4907 (5)0.39934 (16)0.0132 (7)
O130.2302 (5)0.2113 (4)0.38130 (18)0.0131 (7)
O140.1101 (5)0.3849 (4)0.19772 (17)0.0132 (7)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Co10.0073 (4)0.0060 (4)0.0559 (9)000.0023 (5)
Co20.0092 (3)0.0085 (3)0.0131 (4)0.0004 (3)0.0003 (3)0.0004 (3)
V20.0092 (3)0.0085 (3)0.0131 (4)0.0004 (3)0.0003 (3)0.0004 (3)
Co30.0109 (5)0.0116 (5)0.0260 (7)000.0022 (5)
V30.0109 (5)0.0116 (5)0.0260 (7)000.0022 (5)
Co40.0102 (5)0.0075 (5)0.0140 (6)00.0005 (4)0
V40.0102 (5)0.0075 (5)0.0140 (6)00.0005 (4)0
Co50.0118 (3)0.0124 (4)0.0197 (4)0.0005 (3)0.0000 (3)0.0020 (3)
V50.0118 (3)0.0124 (4)0.0197 (4)0.0005 (3)0.0000 (3)0.0020 (3)
P10.0081 (5)0.0056 (5)0.0114 (6)0.0001 (4)0.0015 (5)0.0001 (5)
P20.0078 (5)0.0064 (5)0.0123 (7)0.0010 (4)0.0001 (5)0.0002 (5)
P30.0081 (5)0.0043 (5)0.0100 (5)0.0012 (5)0.0004 (5)0.0004 (5)
P40.0086 (6)0.0070 (5)0.0107 (6)0.0016 (4)0.0009 (5)0.0008 (4)
O10.0080 (14)0.0060 (15)0.0132 (18)0.0023 (14)0.0035 (14)0.0015 (14)
O20.0141 (16)0.0110 (17)0.0133 (19)0.0008 (15)0.0011 (16)0.0030 (15)
O30.0112 (16)0.0081 (15)0.0162 (18)0.0030 (14)0.0014 (16)0.0017 (16)
O40.0163 (18)0.0109 (17)0.017 (2)0.0048 (15)0.0022 (16)0.0004 (15)
O50.0145 (18)0.019 (2)0.0147 (19)0.0017 (15)0.0007 (16)0.0063 (16)
O60.0106 (15)0.0094 (16)0.0157 (18)0.0007 (15)0.0007 (14)0.0009 (14)
O70.0112 (15)0.0103 (17)0.0148 (18)0.0009 (14)0.0018 (14)0.0043 (15)
O80.0179 (19)0.0112 (18)0.0142 (18)0.0027 (15)0.0001 (16)0.0004 (15)
O90.0102 (15)0.0141 (17)0.0171 (19)0.0014 (15)0.0002 (14)0.0024 (16)
O100.0116 (16)0.0128 (17)0.0104 (17)0.0014 (15)0.0032 (14)0.0001 (15)
O110.0107 (16)0.0112 (17)0.030 (2)0.0046 (15)0.0018 (16)0.0011 (17)
O120.0080 (15)0.0157 (18)0.0158 (19)0.0022 (14)0.0008 (14)0.0036 (16)
O130.0114 (16)0.0065 (16)0.021 (2)0.0020 (13)0.0019 (16)0.0014 (15)
O140.0122 (16)0.0170 (19)0.0102 (17)0.0015 (15)0.0014 (15)0.0011 (14)
Geometric parameters (Å, º) top
Co1—O111.968 (4)Co5—O122.065 (4)
Co1—O11i1.968 (4)Co5—O7iv2.076 (4)
Co1—O3i2.044 (4)Co5—O12.082 (4)
Co1—O32.044 (4)Co5—O8iv2.109 (4)
Co2—O14ii1.921 (4)Co5—O22.192 (4)
Co2—O131.937 (4)P1—O11v1.493 (4)
Co2—O102.010 (4)P1—O31.518 (4)
Co2—O12.043 (3)P1—O101.533 (4)
Co2—O62.055 (4)P1—O51.597 (4)
Co2—O22.089 (4)P2—O12vi1.520 (4)
Co3—O3i2.075 (4)P2—O21.527 (4)
Co3—O32.075 (4)P2—O6iv1.531 (4)
Co3—O10iii2.156 (4)P2—O91.582 (4)
Co3—O10iv2.156 (4)P3—O13v1.489 (4)
Co3—O6iii2.274 (4)P3—O81.519 (4)
Co3—O6iv2.274 (4)P3—O11.538 (4)
Co4—O4ii1.969 (4)P3—O5vii1.591 (4)
Co4—O41.969 (4)P4—O41.490 (4)
Co4—O72.097 (4)P4—O141.515 (4)
Co4—O7ii2.097 (4)P4—O7iv1.539 (4)
Co4—O82.148 (4)P4—O9viii1.608 (4)
Co4—O8ii2.148 (4)
O11—Co1—O11i92.7 (3)O11v—P1—O3111.7 (2)
O11—Co1—O3i93.86 (16)O11v—P1—O10113.0 (2)
O11i—Co1—O3i167.12 (17)O3—P1—O10113.1 (2)
O11—Co1—O3167.12 (17)O11v—P1—O5113.6 (2)
O11i—Co1—O393.86 (16)O3—P1—O5106.4 (2)
O3i—Co1—O382.0 (2)O10—P1—O598.3 (2)
O14ii—Co2—O1389.68 (18)O12vi—P2—O2114.9 (3)
O14ii—Co2—O10170.85 (19)O12vi—P2—O6iv112.1 (2)
O13—Co2—O1094.66 (17)O2—P2—O6iv110.5 (2)
O14ii—Co2—O187.68 (16)O12vi—P2—O9104.3 (2)
O13—Co2—O1172.15 (17)O2—P2—O9106.4 (2)
O10—Co2—O189.03 (15)O6iv—P2—O9108.1 (2)
O14ii—Co2—O693.29 (17)O13v—P3—O8115.6 (2)
O13—Co2—O693.32 (16)O13v—P3—O1111.9 (2)
O10—Co2—O678.44 (16)O8—P3—O1112.8 (2)
O1—Co2—O694.22 (15)O13v—P3—O5vii107.4 (2)
O14ii—Co2—O298.53 (17)O8—P3—O5vii103.9 (2)
O13—Co2—O292.24 (16)O1—P3—O5vii104.1 (2)
O10—Co2—O289.36 (16)O4—P4—O14114.2 (2)
O1—Co2—O280.85 (15)O4—P4—O7iv111.2 (2)
O6—Co2—O2166.96 (16)O14—P4—O7iv112.9 (2)
O3i—Co3—O380.5 (2)O4—P4—O9viii108.3 (2)
O3i—Co3—O10iii153.63 (15)O14—P4—O9viii107.6 (2)
O3—Co3—O10iii95.61 (15)O7iv—P4—O9viii101.8 (2)
O3i—Co3—O10iv95.62 (15)P3—O1—Co2125.8 (2)
O3—Co3—O10iv153.62 (15)P3—O1—Co5131.1 (2)
O10iii—Co3—O10iv98.8 (2)Co2—O1—Co5103.14 (16)
O3i—Co3—O6iii82.97 (15)P2—O2—Co2131.7 (3)
O3—Co3—O6iii89.84 (15)P2—O2—Co5130.2 (2)
O10iii—Co3—O6iii70.88 (14)Co2—O2—Co598.01 (17)
O10iv—Co3—O6iii115.74 (14)P1—O3—Co1128.7 (2)
O3i—Co3—O6iv89.84 (15)P1—O3—Co3131.9 (2)
O3—Co3—O6iv82.97 (15)Co1—O3—Co398.73 (16)
O10iii—Co3—O6iv115.73 (14)P4—O4—Co4137.3 (3)
O10iv—Co3—O6iv70.88 (14)P3vii—O5—P1134.8 (3)
O6iii—Co3—O6iv170.60 (19)P2ix—O6—Co2129.6 (2)
O4ii—Co4—O499.4 (3)P2ix—O6—Co3ix122.1 (2)
O4ii—Co4—O787.52 (17)Co2—O6—Co3ix102.37 (16)
O4—Co4—O7158.93 (16)P2ix—O6—V3ix122.1 (2)
O4ii—Co4—O7ii158.93 (16)Co2—O6—V3ix102.37 (16)
O4—Co4—O7ii87.52 (17)P4ix—O7—V5ix128.6 (2)
O7—Co4—O7ii93.1 (2)P4ix—O7—Co5ix128.6 (2)
O4ii—Co4—O893.18 (17)P4ix—O7—Co4125.9 (2)
O4—Co4—O884.36 (17)V5ix—O7—Co4105.46 (17)
O7—Co4—O875.35 (15)Co5ix—O7—Co4105.46 (17)
O7ii—Co4—O8107.37 (16)P3—O8—V5ix127.8 (2)
O4ii—Co4—O8ii84.36 (17)P3—O8—Co5ix127.8 (2)
O4—Co4—O8ii93.18 (17)P3—O8—Co4127.9 (2)
O7—Co4—O8ii107.37 (16)V5ix—O8—Co4102.55 (18)
O7ii—Co4—O8ii75.35 (15)Co5ix—O8—Co4102.55 (18)
O8—Co4—O8ii176.2 (2)P2—O9—P4x135.3 (3)
O12—Co5—O7iv113.79 (16)P1—O10—Co2129.1 (2)
O12—Co5—O192.30 (15)P1—O10—V3ix121.6 (2)
O7iv—Co5—O1101.71 (15)Co2—O10—V3ix108.17 (17)
O12—Co5—O8iv94.11 (16)P1—O10—Co3ix121.6 (2)
O7iv—Co5—O8iv76.62 (15)Co2—O10—Co3ix108.17 (17)
O1—Co5—O8iv173.51 (15)P1vi—O11—Co1150.7 (3)
O12—Co5—O2142.34 (16)P2v—O12—Co5127.2 (2)
O7iv—Co5—O2103.80 (15)P3vi—O13—Co2158.5 (3)
O1—Co5—O277.59 (14)P4—O14—V2ii134.3 (3)
O8iv—Co5—O296.63 (16)P4—O14—Co2ii134.3 (3)
Symmetry codes: (i) x, y, z1; (ii) x, y, z1/2; (iii) x+1/2, y1/2, z1; (iv) x+1/2, y+1/2, z; (v) x+1/2, y1/2, z; (vi) x1/2, y+1/2, z; (vii) x, y1, z1; (viii) x+1/2, y1/2, z1/2; (ix) x1/2, y1/2, z; (x) x+1/2, y+1/2, z1/2.
Acknowledgements top

We thank Dr G. Schnakenburg (University of Bonn) for the data collection.

references
References top

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