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The redetermination of the structure of the title compound, Co2P2O7, agrees with the results previously reported by Krishnamachari & Calvo [Acta Cryst. (1972), B28, 2883-2885], but with improved precision.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536802005342/br6046sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536802005342/br6046Isup2.hkl
Contains datablock I

Key indicators

  • Single-crystal X-ray study
  • T = 173 K
  • Mean [sigma](P-O) = 0.001 Å
  • R factor = 0.024
  • wR factor = 0.049
  • Data-to-parameter ratio = 13.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


Red Alert Alert Level A:
DIFF_019 Alert A _diffrn_standards_number is missing Number of standards used in measurement. DIFF_020 Alert A _diffrn_standards_interval_count and _diffrn_standards_interval_time are missing. Number of measurements between standards or time (min) between standards.
2 Alert Level A = Potentially serious problem
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Comment top

The original structure of the title compound was reported by Krishnamachari & Calvo (1972) using the unconventional space group B21/c for comparison with the structure of Mg2P2O7 (Calvo, 1967). In addition, the magnetic structure of the title compound had been determined (Forsyth et al., 1989). We used the conventional space group P21/c for rerefinement. A perspective view of the title compound is shown in Fig. 1. Both structures agree well, but the present work is of improved precision.

Experimental top

SrCO3, CoCO3 and (NH4)2HPO4 were mixed in a ratio of 1:3:2. The mixture was heated progressively in air at increasing temperatures up to 1173 K. Then, 100 mg iodine and 10 mg red phosphorous were added and the mixture was sealed in an evacuated silica ampoule. The ampoule was transferred to a tubular furnace where it was heated for a week at 973 K. The reaction product was washed with dilute NaOH and water and dried at 373 K. Two kinds of crystals were obtained: pink crystals have been identified as Co2P4O12 (Nord, 1982; Olbertz et al., 1998), dark red crystals were composed of the title compound.

Computing details top

Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 1991).

Figures top
[Figure 1] Fig. 1. The title compound with atom labelling and displacement ellipsiods drawn at the 50% probability level. Symmetry operators for generating equivalent atoms: O2A: x, 1.5 - y, z - 0.5; O2B: 1 - x, y - 0.5, 1.5 - z; O3A: 1 - x, 1.5 - y, 1 - z; O3B: 2 - x, y - 0.5, 1.5 - z; O4A: x - 1, y, z - 1; O4B: 1 - x, 2 - y, 1 - z; O6A: x, 1.5 - y, z + 0.5; O7A: 1 - x, y + 0.5, 0.5 - z; O7B: 1 - x, 1 - y, 1 - z.
; top
Crystal data top
Co2P2O7F(000) = 560
Mr = 291.80Dx = 4.008 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 7.0022 (9) ÅCell parameters from 10799 reflections
b = 8.3634 (11) Åθ = 3.2–30.0°
c = 9.0114 (12) ŵ = 7.50 mm1
β = 113.600 (9)°T = 173 K
V = 483.59 (11) Å3Block, dark red
Z = 40.29 × 0.18 × 0.12 mm
Data collection top
Stoe IPDS II two-circle
diffractometer
1389 independent reflections
Radiation source: fine-focus sealed tube1307 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.048
ω scansθmax = 29.9°, θmin = 3.2°
Absorption correction: empirical
(MULABS; Spek, 1990; Blessing, 1995)
h = 99
Tmin = 0.200, Tmax = 0.406k = 1111
7237 measured reflectionsl = 1112
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.024 w = 1/[σ2(Fo2) + (0.0278P)2 + 0.0813P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.049(Δ/σ)max = 0.001
S = 1.12Δρmax = 0.50 e Å3
1389 reflectionsΔρmin = 0.47 e Å3
101 parametersExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.0252 (15)
Crystal data top
Co2P2O7V = 483.59 (11) Å3
Mr = 291.80Z = 4
Monoclinic, P21/cMo Kα radiation
a = 7.0022 (9) ŵ = 7.50 mm1
b = 8.3634 (11) ÅT = 173 K
c = 9.0114 (12) Å0.29 × 0.18 × 0.12 mm
β = 113.600 (9)°
Data collection top
Stoe IPDS II two-circle
diffractometer
1389 independent reflections
Absorption correction: empirical
(MULABS; Spek, 1990; Blessing, 1995)
1307 reflections with I > 2σ(I)
Tmin = 0.200, Tmax = 0.406Rint = 0.048
7237 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.024101 parameters
wR(F2) = 0.0490 restraints
S = 1.12Δρmax = 0.50 e Å3
1389 reflectionsΔρmin = 0.47 e Å3
Special details top

Experimental. ;

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
Co10.23247 (3)0.92882 (3)0.10884 (2)0.00799 (8)
Co20.69933 (3)0.44157 (2)0.82475 (2)0.00860 (8)
P10.94042 (6)0.76797 (4)0.75824 (4)0.00746 (9)
P20.53170 (5)0.77429 (4)0.46771 (4)0.00713 (9)
O10.74908 (16)0.82989 (14)0.60005 (12)0.0110 (2)
O20.37848 (17)0.76488 (13)0.54938 (13)0.0096 (2)
O31.11902 (16)0.75915 (12)0.70267 (13)0.0093 (2)
O40.97662 (17)0.90145 (13)0.88165 (13)0.0095 (2)
O50.88706 (18)0.61064 (14)0.81112 (14)0.0126 (2)
O60.48086 (17)0.90934 (13)0.34431 (13)0.0092 (2)
O70.55344 (17)0.61280 (14)0.39749 (13)0.0097 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Co10.00769 (12)0.00809 (12)0.00812 (12)0.00033 (6)0.00307 (9)0.00007 (6)
Co20.00846 (11)0.00823 (12)0.00975 (11)0.00018 (6)0.00431 (8)0.00030 (6)
P10.00673 (16)0.00807 (17)0.00767 (16)0.00038 (11)0.00298 (13)0.00058 (11)
P20.00668 (16)0.00790 (17)0.00660 (15)0.00011 (11)0.00244 (13)0.00014 (11)
O10.0080 (5)0.0128 (5)0.0092 (5)0.0003 (3)0.0004 (4)0.0007 (4)
O20.0098 (5)0.0102 (5)0.0102 (4)0.0013 (4)0.0054 (4)0.0008 (4)
O30.0083 (5)0.0101 (5)0.0102 (4)0.0003 (3)0.0044 (4)0.0001 (4)
O40.0097 (5)0.0103 (5)0.0083 (5)0.0010 (4)0.0034 (4)0.0016 (4)
O50.0137 (5)0.0099 (5)0.0166 (5)0.0018 (4)0.0085 (4)0.0004 (4)
O60.0096 (5)0.0091 (5)0.0083 (4)0.0007 (3)0.0031 (4)0.0013 (3)
O70.0100 (5)0.0090 (5)0.0095 (5)0.0008 (4)0.0032 (4)0.0012 (4)
Geometric parameters (Å, º) top
Co1—O4i2.0655 (11)P1—O11.6019 (11)
Co1—O3ii2.0869 (11)P2—O61.5239 (11)
Co1—O2iii2.0966 (11)P2—O71.5248 (12)
Co1—O4iv2.1253 (12)P2—O21.5268 (11)
Co1—O62.1445 (11)P2—O11.5817 (11)
Co1—O7v2.1649 (12)O2—Co2x2.0643 (11)
Co2—O51.9677 (12)O2—Co1vi2.0965 (11)
Co2—O6vi2.0352 (11)O3—Co2xi2.0636 (11)
Co2—O3vii2.0636 (11)O3—Co1xii2.0869 (11)
Co2—O2viii2.0643 (11)O4—Co1i2.0655 (11)
Co2—O7ix2.1242 (11)O4—Co1xiii2.1253 (11)
P1—O51.4968 (12)O6—Co2iii2.0352 (11)
P1—O41.5237 (12)O7—Co2ix2.1242 (11)
P1—O31.5237 (12)O7—Co1xiv2.1649 (12)
O4i—Co1—O3ii96.30 (5)O4—P1—O3110.90 (6)
O4i—Co1—O2iii165.45 (4)O5—P1—O1109.94 (7)
O3ii—Co1—O2iii79.93 (5)O4—P1—O1104.36 (6)
O4i—Co1—O4iv77.05 (5)O3—P1—O1103.14 (6)
O3ii—Co1—O4iv89.91 (4)O6—P2—O7112.75 (7)
O2iii—Co1—O4iv88.84 (4)O6—P2—O2112.71 (6)
O4i—Co1—O6108.59 (4)O7—P2—O2111.13 (6)
O3ii—Co1—O680.29 (4)O6—P2—O1101.86 (6)
O2iii—Co1—O684.77 (4)O7—P2—O1110.33 (6)
O4iv—Co1—O6169.10 (5)O2—P2—O1107.55 (6)
O4i—Co1—O7v91.29 (5)P2—O1—P1141.76 (8)
O3ii—Co1—O7v157.83 (4)P2—O2—Co2x128.23 (6)
O2iii—Co1—O7v97.40 (4)P2—O2—Co1vi132.20 (6)
O4iv—Co1—O7v112.13 (4)Co2x—O2—Co1vi98.61 (5)
O6—Co1—O7v77.54 (4)P1—O3—Co2xi129.05 (6)
O5—Co2—O6vi96.27 (5)P1—O3—Co1xii131.70 (6)
O5—Co2—O3vii93.70 (5)Co2xi—O3—Co1xii98.95 (5)
O6vi—Co2—O3vii169.76 (4)P1—O4—Co1i128.33 (7)
O5—Co2—O2viii151.47 (5)P1—O4—Co1xiii127.72 (7)
O6vi—Co2—O2viii91.04 (4)Co1i—O4—Co1xiii102.95 (5)
O3vii—Co2—O2viii81.23 (5)P1—O5—Co2155.46 (8)
O5—Co2—O7ix114.85 (5)P2—O6—Co2iii123.59 (6)
O6vi—Co2—O7ix80.87 (5)P2—O6—Co1129.67 (6)
O3vii—Co2—O7ix92.85 (4)Co2iii—O6—Co1101.99 (5)
O2viii—Co2—O7ix93.51 (5)P2—O7—Co2ix113.39 (6)
O5—P1—O4113.67 (7)P2—O7—Co1xiv145.67 (7)
O5—P1—O3113.85 (6)Co2ix—O7—Co1xiv98.47 (5)
Symmetry codes: (i) x+1, y+2, z+1; (ii) x1, y+3/2, z1/2; (iii) x, y+3/2, z1/2; (iv) x1, y, z1; (v) x+1, y+1/2, z+1/2; (vi) x, y+3/2, z+1/2; (vii) x+2, y1/2, z+3/2; (viii) x+1, y1/2, z+3/2; (ix) x+1, y+1, z+1; (x) x+1, y+1/2, z+3/2; (xi) x+2, y+1/2, z+3/2; (xii) x+1, y+3/2, z+1/2; (xiii) x+1, y, z+1; (xiv) x+1, y1/2, z+1/2.

Experimental details

Crystal data
Chemical formulaCo2P2O7
Mr291.80
Crystal system, space groupMonoclinic, P21/c
Temperature (K)173
a, b, c (Å)7.0022 (9), 8.3634 (11), 9.0114 (12)
β (°) 113.600 (9)
V3)483.59 (11)
Z4
Radiation typeMo Kα
µ (mm1)7.50
Crystal size (mm)0.29 × 0.18 × 0.12
Data collection
DiffractometerStoe IPDS II two-circle
diffractometer
Absorption correctionEmpirical
(MULABS; Spek, 1990; Blessing, 1995)
Tmin, Tmax0.200, 0.406
No. of measured, independent and
observed [I > 2σ(I)] reflections
7237, 1389, 1307
Rint0.048
(sin θ/λ)max1)0.702
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.024, 0.049, 1.12
No. of reflections1389
No. of parameters101
Δρmax, Δρmin (e Å3)0.50, 0.47

Computer programs: X-AREA (Stoe & Cie, 2001), X-AREA, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), XP in SHELXTL-Plus (Sheldrick, 1991).

Selected geometric parameters (Å, º) top
Co1—O4i2.0655 (11)Co2—O7ix2.1242 (11)
Co1—O3ii2.0869 (11)P1—O51.4968 (12)
Co1—O2iii2.0966 (11)P1—O41.5237 (12)
Co1—O4iv2.1253 (12)P1—O31.5237 (12)
Co1—O62.1445 (11)P1—O11.6019 (11)
Co1—O7v2.1649 (12)P2—O61.5239 (11)
Co2—O51.9677 (12)P2—O71.5248 (12)
Co2—O6vi2.0352 (11)P2—O21.5268 (11)
Co2—O3vii2.0636 (11)P2—O11.5817 (11)
Co2—O2viii2.0643 (11)
P2—O1—P1141.76 (8)
Symmetry codes: (i) x+1, y+2, z+1; (ii) x1, y+3/2, z1/2; (iii) x, y+3/2, z1/2; (iv) x1, y, z1; (v) x+1, y+1/2, z+1/2; (vi) x, y+3/2, z+1/2; (vii) x+2, y1/2, z+3/2; (viii) x+1, y1/2, z+3/2; (ix) x+1, y+1, z+1.
 

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