BaCo(2)(AsO(4))(2).

Suitable single crystals of the title compound, barium dicobalt(II) bis-[orthoarsenate(V)], were prepared under hydro-thermal conditions. This phase belongs to a series of compounds with general formula AM(2)(XO(4))(2), where A = alkaline earth metal, M = Mg or a divalent first-row transition element, and X = P, As or V. BaCo(2)(AsO(4))(2) is isotypic with BaNi(2)(XO(4))(2) (X = P, V or As) and is characterized by brucite-like sheets of edge-sharing CoO(6) octa-hedra (3 symmetry) parallel to (001), with one-third of the octa-hedral positions being vacant. The sheets are capped above and below by AsO(4) tetra-hedra (3 symmetry) and are inter-connected by distorted BaO(12) cubocta-hedra ( symmetry).

Related literature

For isostructural compounds, see: Eymond et al. (1969a ▶,b ▶); Bircsak & Harrison (1998 ▶); El-Bali et al. (1999 ▶); Faza et al. (2001 ▶); Rogado et al. (2002 ▶); Wichmann, & Müller-Buschbaum (1984 ▶). For magnetic properties of BaCo2(AsO4)2, see: Dojčilović et al. (1994 ▶); Regnault et al. (2006 ▶). For related compounds, see: Effenberger & Pertlik (1993 ▶); El-Bali et al. (1993a ▶,b ▶); Hemon & Courbion (1990 ▶); Kreidler & Hummel (1961 ▶); Lucas et al. (1998 ▶); Mihajlović et al. (2004 ▶); Moquine et al. (1993 ▶); Osterloh & Müller-Buschbaum (1994 ▶). For general background, see: Brese & O’Keeffe (1991 ▶).

Experimental

Crystal data

BaCo2(AsO4)2

M = 533.04

Hexagonal,

a = 5.007 (1) Å

c = 23.491 (5) Å

V = 510.02 (18) Å3

Z = 3

Mo Kα radiation

μ = 20.22 mm−1

T = 293 (2) K

0.09 × 0.05 × 0.05 mm

Data collection

Nonius KappaCCD diffractometer

Absorption correction: multi-scan (Otwinowski & Minor, 1997 ▶; Otwinowski et al., 2003 ▶) T min = 0.221, T max = 0.362

681 measured reflections

341 independent reflections

336 reflections with I > 2σ(I)

R int = 0.009

Refinement

R[F 2 > 2σ(F 2)] = 0.014

wR(F 2) = 0.038

S = 1.30

341 reflections

22 parameters

Δρmax = 0.96 e Å−3

Δρmin = −1.09 e Å−3

Data collection: COLLECT (Nonius, 2002 ▶); cell refinement: SCALEPACK (Otwinowski & Minor, 1997 ▶); data reduction: DENZO-SMN (Otwinowski et al., 2003 ▶); method used to solve structure: starting parameters from an isostructural compound (Eymond et al., 1969a ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶) and WinGX (Farrugia, 1999 ▶); molecular graphics: ATOMS (Dowty, 2000 ▶); software used to prepare material for publication: publCIF (Westrip, 2008 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808025865/wm2189sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808025865/wm2189Isup2.hkl

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

BaCo2(AsO4)2	Z = 3
Mr = 533.04	F000 = 720
Hexagonal, R3	Dx = 5.206 Mg m−3
Hall symbol: -R 3	Mo Kα radiation λ = 0.71073 Å
a = 5.007 (1) Å	Cell parameters from 675 reflections
b = 5.007 (1) Å	θ = 1.0–30.0º
c = 23.491 (5) Å	µ = 20.22 mm−1
α = 90º	T = 293 (2) K
β = 90º	Pseudo-hexagonal plate, pink
γ = 120º	0.09 × 0.05 × 0.05 mm
V = 510.02 (18) Å3

Nonius KappaCCD diffractometer	341 independent reflections
Radiation source: fine-focus sealed tube	336 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.009
T = 293(2) K	θmax = 30.0º
φ and ω scans	θmin = 2.6º
Absorption correction: multi-scan(Otwinowski & Minor, 1997; Otwinowski et al., 2003)	h = −7→7
Tmin = 0.221, Tmax = 0.362	k = −5→5
681 measured reflections	l = −33→33

Refinement on F2	Primary atom site location: isomorphous structure methods
Least-squares matrix: full	w = 1/[σ2(Fo2) + (0.0133P)2 + 3.104P] where P = (Fo2 + 2Fc2)/3
R[F2 > 2σ(F2)] = 0.014	(Δ/σ)max < 0.001
wR(F2) = 0.038	Δρmax = 0.96 e Å−3
S = 1.30	Δρmin = −1.09 e Å−3
341 reflections	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
22 parameters	Extinction coefficient: 0.0118 (5)

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.

	x	y	z	Uiso*/Ueq
Ba1	0.0000	0.0000	0.0000	0.01170 (15)
Co1	0.0000	0.0000	0.17014 (2)	0.00614 (16)
As1	0.3333	0.6667	0.091941 (18)	0.00473 (15)
O1	0.3333	0.6667	0.02145 (13)	0.0118 (6)
O2	0.0163 (4)	0.3375 (4)	0.11476 (7)	0.0077 (3)

	U11	U22	U33	U12	U13	U23
Ba1	0.01138 (17)	0.01138 (17)	0.0124 (2)	0.00569 (8)	0.000	0.000
Co1	0.00474 (19)	0.00474 (19)	0.0089 (3)	0.00237 (9)	0.000	0.000
As1	0.00414 (16)	0.00414 (16)	0.0059 (2)	0.00207 (8)	0.000	0.000
O1	0.0149 (9)	0.0149 (9)	0.0055 (13)	0.0075 (5)	0.000	0.000
O2	0.0055 (7)	0.0050 (7)	0.0116 (8)	0.0019 (6)	0.0017 (6)	0.0020 (6)

Ba1—O1i	2.9344 (8)	Ba1—O2ix	3.1611 (17)
Ba1—O1ii	2.9344 (8)	Co1—O2x	2.0791 (17)
Ba1—O1iii	2.9344 (8)	Co1—O2xi	2.0791 (17)
Ba1—O1	2.9344 (8)	Co1—O2xii	2.0792 (17)
Ba1—O1iv	2.9344 (8)	Co1—O2vii	2.1017 (17)
Ba1—O1v	2.9344 (8)	Co1—O2	2.1017 (17)
Ba1—O2vi	3.1611 (17)	Co1—O2vi	2.1017 (17)
Ba1—O2	3.1611 (17)	As1—O1	1.656 (3)
Ba1—O2vii	3.1611 (17)	As1—O2xiii	1.7050 (17)
Ba1—O2iii	3.1611 (17)	As1—O2	1.7050 (17)
Ba1—O2viii	3.1611 (17)	As1—O2xiv	1.7050 (17)
O1i—Ba1—O1ii	180.00 (12)	O2vii—Ba1—O2iii	126.22 (5)
O1i—Ba1—O1iii	117.11 (3)	O1i—Ba1—O2viii	52.94 (6)
O1ii—Ba1—O1iii	62.89 (3)	O1ii—Ba1—O2viii	127.06 (6)
O1i—Ba1—O1	62.89 (3)	O1iii—Ba1—O2viii	82.85 (6)
O1ii—Ba1—O1	117.11 (3)	O1—Ba1—O2viii	97.15 (6)
O1iii—Ba1—O1	180.00 (12)	O1iv—Ba1—O2viii	106.72 (6)
O1i—Ba1—O1iv	117.11 (3)	O1v—Ba1—O2viii	73.28 (6)
O1ii—Ba1—O1iv	62.89 (3)	O2vi—Ba1—O2viii	180.00 (7)
O1iii—Ba1—O1iv	117.11 (3)	O2—Ba1—O2viii	126.22 (5)
O1—Ba1—O1iv	62.89 (3)	O2vii—Ba1—O2viii	126.22 (5)
O1i—Ba1—O1v	62.89 (3)	O2iii—Ba1—O2viii	53.78 (5)
O1ii—Ba1—O1v	117.11 (3)	O1i—Ba1—O2ix	82.85 (6)
O1iii—Ba1—O1v	62.89 (3)	O1ii—Ba1—O2ix	97.15 (6)
O1—Ba1—O1v	117.11 (3)	O1iii—Ba1—O2ix	106.72 (6)
O1iv—Ba1—O1v	180.00 (12)	O1—Ba1—O2ix	73.28 (6)
O1i—Ba1—O2vi	127.06 (6)	O1iv—Ba1—O2ix	52.94 (6)
O1ii—Ba1—O2vi	52.94 (6)	O1v—Ba1—O2ix	127.06 (6)
O1iii—Ba1—O2vi	97.15 (6)	O2vi—Ba1—O2ix	126.22 (5)
O1—Ba1—O2vi	82.85 (6)	O2—Ba1—O2ix	126.22 (5)
O1iv—Ba1—O2vi	73.28 (6)	O2vii—Ba1—O2ix	180.00 (3)
O1v—Ba1—O2vi	106.72 (6)	O2iii—Ba1—O2ix	53.78 (5)
O1i—Ba1—O2	73.28 (6)	O2viii—Ba1—O2ix	53.78 (5)
O1ii—Ba1—O2	106.72 (6)	O2x—Co1—O2xi	92.91 (7)
O1iii—Ba1—O2	127.06 (6)	O2x—Co1—O2xii	92.91 (7)
O1—Ba1—O2	52.94 (6)	O2xi—Co1—O2xii	92.91 (7)
O1iv—Ba1—O2	97.15 (6)	O2x—Co1—O2vii	92.34 (6)
O1v—Ba1—O2	82.85 (6)	O2xi—Co1—O2vii	174.36 (6)
O2vi—Ba1—O2	53.78 (5)	O2xii—Co1—O2vii	88.86 (9)
O1i—Ba1—O2vii	97.15 (6)	O2x—Co1—O2	174.36 (6)
O1ii—Ba1—O2vii	82.85 (6)	O2xi—Co1—O2	88.86 (9)
O1iii—Ba1—O2vii	73.28 (6)	O2xii—Co1—O2	92.34 (6)
O1—Ba1—O2vii	106.72 (6)	O2vii—Co1—O2	85.72 (7)
O1iv—Ba1—O2vii	127.06 (6)	O2x—Co1—O2vi	88.86 (9)
O1v—Ba1—O2vii	52.94 (6)	O2xi—Co1—O2vi	92.34 (6)
O2vi—Ba1—O2vii	53.78 (5)	O2xii—Co1—O2vi	174.36 (6)
O2—Ba1—O2vii	53.78 (5)	O2vii—Co1—O2vi	85.72 (7)
O1i—Ba1—O2iii	106.72 (6)	O2—Co1—O2vi	85.72 (7)
O1ii—Ba1—O2iii	73.28 (6)	O1—As1—O2xiii	108.33 (6)
O1iii—Ba1—O2iii	52.94 (6)	O1—As1—O2	108.33 (6)
O1—Ba1—O2iii	127.06 (6)	O2xiii—As1—O2	110.59 (5)
O1iv—Ba1—O2iii	82.85 (6)	O1—As1—O2xiv	108.33 (6)
O1v—Ba1—O2iii	97.15 (6)	O2xiii—As1—O2xiv	110.59 (5)
O2vi—Ba1—O2iii	126.22 (5)	O2—As1—O2xiv	110.59 (5)
O2—Ba1—O2iii	180.00 (7)

Table 1

Selected bond lengths (Å)

Ba1—O1	2.9344 (8)
Ba1—O2	3.1611 (17)
Co1—O2i	2.0791 (17)
Co1—O2	2.1017 (17)
As1—O1	1.656 (3)
As1—O2	1.7050 (17)

Symmetry code: (i) .