Lithium cobalt(II) pyrophosphate, Li(1.86)CoP(2)O(7), from synchrotron X-ray powder data.

Structure refinement of high-resolution X-ray powder diffraction data of the title compound gave the composition Li(1.865)CoP(2)O(7), which is also verified by the ICP measurement. Two Co sites exist in the structure: one is a CoO(5) square pyramid and the other is a CoO(6) octa-hedron. They share edges and are further inter-connected through P(2)O(7) groups, forming a three-dimensional framework, which exhibits different kinds of inter-secting tunnels containing Li cations and could be of great inter-est in Li ion battery chemistry. The structure also exhibits cation disorder with 13.5% Co residing at the lithium (Li1) site. Co seems to have an average oxidation state of 2.135, as obtained from the strutural stochiometry that closely supports the magnetic susceptibility findings.

Related literature

For related structures, see: Adam et al. (2008 ▶); Nishimura et al. (2010 ▶); Zhou et al. (2011 ▶). For related materials with Na+ and K+ cations, see: Erragh et al. (1991 ▶); Sanz et al. (1999 ▶); Beaury et al. (2004 ▶); Gopalakrishna et al. (2005 ▶); Bih et al. (2006 ▶); Guesmi et al. (2007 ▶). For related structural frameworks, see: Beaury et al. (2004 ▶); Fagginani & Calvo (1976) ▶; Sandström et al. (2003 ▶); Etheredge & Hwu (1995 ▶); El Maadi et al. (1995 ▶); Huang & Hwa (1998 ▶); Sanz et al. (1999 ▶); Erragh et al. (1998 ▶). Pseudovoigt profile coefficients as parameterized in Thompson et al. (1987 ▶) and Finger et al. (1994 ▶).

Experimental

Crystal data

CoLi1.865O7P2

M = 245.82

Monoclinic,

a = 9.76453 (4) Å

b = 9.69622 (4) Å

c = 10.95952 (4) Å

β = 101.7664 (2)°

V = 1015.83 (1) Å3

Z = 8

Synchrotron radiation, λ = 0.413988 Å

μ = 0.89 mm−1

T = 297 K

irregular shape, 15 × 13 mm

Data collection

Advanced Photon Source diffractometer

Specimen mounting: kapton capillary

Data collection mode: transmission

Scan method: continuous

Refinement

R p = 0.057

R wp = 0.080

R exp = 0.049

R(F 2) = 0.04534

χ2 = 2.624

24500 data points

269 parameters

Data collection: Advance Photon Source Argonne National Laboratory; cell refinement: GSAS (Larson & Von Dreele, 2000 ▶); data reduction: Powder4 (Dragoe, 2001 ▶); program(s) used to solve structure: GSAS; program(s) used to refine structure: GSAS; molecular graphics: CrystalMaker (Palmer, 2005 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S1600536811038451/br2175sup1.cif

Rietveld powder data: contains datablock(s) I. DOI: 10.1107/S1600536811038451/br2175Isup2.rtv

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

CoLi1.865O7P2	F(000) = 948.7
Mr = 245.82	Dx = 3.214 Mg m−3
Monoclinic, P21/a	Melting point: 1023 K
Hall symbol: -P 2yab	Synchrotron radiation, λ = 0.413988 Å
a = 9.76453 (4) Å	µ = 0.89 mm−1
b = 9.69622 (4) Å	T = 297 K
c = 10.95952 (4) Å	Particle morphology: block
β = 101.7664 (2)°	pink
V = 1015.83 (1) Å3	irregular, 15 × 13 mm
Z = 8	Specimen preparation: Prepared at 873 K and 101.325 kPa

Advanced Photon Source diffractometer	Specimen mounting: kapton capillary
Radiation source: Synchrotron	Data collection mode: transmission
Si	Scan method: continuous

Least-squares matrix: full	Excluded region(s): Reflections exceeding 2-theta 30 were omitted for the ease of refinement.
Rp = 0.057	Profile function: CW Profile function number 3 with 19 terms Pseudovoigt profile coefficients as parameterized in Thompson et al., (1987) and Finger et al. (1994).#1(GU) = 6.454 #2(GV) = -0.998 #3(GW) = 0.075 #4(GP) = 0.000 #5(LX) = 0.327 #6(LY) = 0.000 #7(S/L) = 0.0011 #8(H/L) = 0.0014 #9(trns) = 0.00 #10(shft)= 0.0000 #11(stec)= 0.00 #12(ptec)= 0.00 #13(sfec)= 0.00 #14(L11) = 0.067 #15(L22) = 0.070 #16(L33) = 0.058 #17(L12) = 0.010 #18(L13) = 0.010 #19(L23) = -0.004 Peak tails are ignored where the intensity is below 0.0010 times the peak Aniso. broadening axis 0.0 0.0 1.0
Rwp = 0.080	269 parameters
Rexp = 0.049	0 restraints
R(F2) = 0.04534	(Δ/σ)max = 0.03
χ2 = 2.624	Background function: GSAS Background function number 1 with 36 terms. Shifted Chebyshev function of 1st kind 1: 165.338 2: -31.4210 3: -8.19118 4: 6.28432 5: -10.8524 6: 14.3842 7: -8.22810 8: -0.949190 9: 13.3092 10: -14.8044 11: 4.75285 12: -1.09442 13: -0.739293 14: 5.47743 15: -2.87265 16: 1.05489 17: -3.22764 18: 1.21714 19: 0.537209 20: -3.25962 21: 2.18736 22: -1.12437 23: -2.15219 24: 3.41374 25: -3.88852 26: 1.14500 27: 3.06741 28: -3.05038 29: 0.529274 30: 0.298855 31: -4.06399 32: 1.50867 33: 1.15056 34: -2.20673 35: 0.550944 36: 5.540140E-02
24500 data points

Experimental. Data was collected with powder sample packed in Kapton capillary

	x	y	z	Uiso*/Ueq	Occ. (<1)
Co1	0.25281 (15)	0.71550 (15)	0.18010 (14)	0.0137 (4)*	0.73
Co2	0.30165 (11)	0.43043 (11)	0.32719 (10)	0.0095 (3)*
P1	0.3790 (2)	0.6536 (2)	0.5771 (2)	0.0078 (5)*
P2	0.0613 (2)	0.9265 (2)	0.24116 (18)	0.0089 (5)*
P3	0.0210 (2)	0.4551 (2)	0.75861 (19)	0.0103 (5)*
P4	0.6144 (2)	0.7956 (2)	−0.1113 (2)	0.0117 (6)*
O1	0.1615 (5)	0.8210 (5)	0.3113 (5)	0.0130 (14)*
O2	0.4709 (5)	0.7806 (5)	−0.0792 (4)	0.0106 (12)*
O3	0.3911 (5)	0.8599 (4)	0.1472 (5)	0.0107 (13)*
O4	0.0302 (5)	0.8437 (5)	0.5592 (4)	0.0116 (14)*
O5	0.4330 (5)	0.4292 (5)	−0.1033 (4)	0.0168 (13)*
O6	0.1790 (5)	0.8356 (5)	−0.1511 (4)	0.0115 (13)*
O7	0.0189 (5)	0.4120 (4)	0.6224 (4)	0.0087 (13)*
O8	0.1866 (5)	0.2976 (4)	0.4146 (4)	0.0047 (12)*
O9	0.1013 (5)	0.6017 (4)	0.7747 (4)	0.0116 (13)*
O10	0.3827 (5)	0.5734 (5)	0.7087 (4)	0.0061 (12)*
O11	0.4152 (5)	0.5900 (4)	0.2661 (4)	0.0085 (13)*
O12	0.2775 (5)	0.5646 (5)	0.4803 (4)	0.0134 (13)*
O13	0.3713 (5)	1.0314 (5)	−0.2124 (5)	0.0205 (15)*
O14	0.2204 (5)	0.6299 (5)	−0.0018 (4)	0.0094 (13)*
Li1	1.3433 (3)	0.9255 (3)	−0.0397 (3)	0.0087 (7)*	0.73
Li2	0.0807 (17)	0.1083 (15)	0.0261 (15)	0.009 (4)*
Li3	0.6728 (15)	0.0711 (14)	0.5465 (14)	0.029 (4)*
Li4	0.400 (2)	0.246 (2)	0.5725 (17)	0.065 (7)*
Co3	1.3433 (3)	0.9255 (3)	−0.0397 (3)	0.0087 (7)*	0.27

Co1—O1	2.105 (5)	P2—O5v	1.524 (4)
Co1—O3	2.028 (4)	P2—O10iv	1.584 (5)
Co1—O11	2.067 (4)	P2—O11vi	1.516 (5)
Co1—O13i	2.226 (5)	P3—O3ii	1.514 (5)
Co1—O14	2.123 (5)	P3—O7	1.546 (5)
Co2—O4ii	2.030 (5)	P3—O9	1.616 (4)
Co2—O6i	2.180 (5)	P3—O13vii	1.563 (5)
Co2—O8	2.068 (4)	P4—O2	1.519 (5)
Co2—O11	2.091 (4)	P4—O6iii	1.524 (4)
Co2—O12	2.173 (4)	P4—O9viii	1.582 (5)
Co2—O13i	2.128 (5)	P4—O14iii	1.589 (5)
P1—O4iii	1.529 (5)	Co3—O2ix	1.983 (5)
P1—O8iv	1.547 (4)	Co3—O3ix	2.104 (6)
P1—O10	1.633 (5)	Co3—O6ix	2.006 (6)
P1—O12	1.556 (4)	Co3—O13ix	2.220 (5)
P2—O1	1.512 (5)	Co3—O14x	2.154 (5)
O1—Co1—O3	100.14 (19)	O8—Co2—O11	169.24 (17)
O1—Co1—O11	111.53 (19)	O8—Co2—O13i	96.85 (19)
O1—Co1—O14	145.94 (21)	O11—Co2—O13i	83.05 (18)
O3—Co1—O11	90.63 (18)	O8iv—P1—O10	108.18 (27)
O3—Co1—O14	94.60 (20)	O8iv—P1—O12	109.11 (29)
O11—Co1—O14	98.73 (18)	O10—P1—O12	103.57 (26)
O4ii—Co2—O8	84.60 (18)	O1—P2—O5v	111.42 (29)
O4ii—Co2—O11	95.03 (18)	O1—P2—O10iv	106.90 (27)
O4ii—Co2—O13i	177.02 (20)	O5v—P2—O10iv	104.39 (29)