BaMn^II ₂Mn^III(PO₄)₃

Abstract

The title compound, barium trimanganese tris­(ortho­phosphate), was synthesized hydro­thermally. Its structure is isotypic with the lead and strontium analogues AMn^II ₂Mn^III(PO₄)₃ (A = Pb, Sr). Except for two O atoms on general positions, all atoms are located on special positions. The Ba and one P atom exhibit mm2 symmetry, the Mn^II atom 2/m symmetry, the Mn^III atom and the other P atom .2. symmetry and two O atoms are located on mirror planes. The crystal structure contains two types of chains running parallel to [010]. One chain is linear and is composed of alternating Mn^IIIO₆ octa­hedra and PO₄ tetra­hedra sharing vertices; the other chain has a zigzag arrangement and is built up from two edge-sharing Mn^IIO₆ octa­hedra connected to PO₄ tetra­hedra by edges and vertices. The two types of chains are linked through PO₄ tetra­hedra into an open three-dimensional framework which contains channels parallel to [100] and [010] in which the Ba^II ions are located. The alkaline earth cation is surrounded by eight O atoms in the form of a slightly distorted bicapped trigonal prism.

Related literature  

For the isotypic lead and strontium analogues, see: Alhakmi et al. (2013a ▶) and (2013b ▶), respectively. For related structures, see: Adam et al. (2009 ▶); Assani et al. (2011a ▶,b ▶). For bond-valence analysis, see: Brown & Altermatt (1985 ▶). For the by- product phase, see: Moore & Araki (1973 ▶).

Experimental  

Crystal data  

• BaMn₃(PO₄)₃

• M _r = 587.07

• Orthorhombic,

• a = 10.3038 (7) Å

• b = 14.0163 (11) Å

• c = 6.7126 (4) Å

• V = 969.44 (12) ų

• Z = 4

• Mo Kα radiation

• μ = 8.39 mm⁻¹

• T = 296 K

• 0.29 × 0.17 × 0.13 mm

Data collection  

• Bruker X8 APEX diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.164, T _max = 0.376

• 3968 measured reflections

• 811 independent reflections

• 732 reflections with I > 2σ(I)

• R _int = 0.032

Refinement  

• R[F ² > 2σ(F ²)] = 0.020

• wR(F ²) = 0.055

• S = 1.09

• 811 reflections

• 53 parameters

• Δρ_max = 1.86 e Å⁻³

• Δρ_min = −0.78 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

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

supplementary crystallographic information

1. Comment

Investigating functional compounds by means of the hydrothermal process, particularly phosphates, we have succeeded to synthesize and structurally characterize new mixed-cation orthophosphates with open frameworks, e.g. the isotypic pair Ag₂M₃(HPO₄)(PO₄)₂ (M = Co, Ni) (Assani et al., 2011a,b) that is closely related to the alluaudite structure. Others investigated phosphates include compounds crystallizing in the AMn^II₂Mn^III(PO₄)₃ (A = Pb, Sr) structure type (Alhakmi et al. (2013a,b) with rarely observed mixed-valent Mn^II/III cations (Adam et al., 2009). The present article reports on synthesis and crystal structure of the isotypic barium analogue, BaMn^II₂Mn^III(PO₄)₃.

All atoms of this structure are in special positions, except two oxygen atoms (O3, O4) in general position of space group Imma. The connection of the metal-oxygen polyhedra, viz. BaO₈ polyhedra, MnO₆ octahedra and PO₄ tetrahedra is shown in Fig. 1. The framework of the crystal structure consists of two isolated PO₄ tetrahedra linked to MnO₆ octahedra, building two types of chains running along [010]. The first chain is formed by alternating Mn^IIIO₆ octahedra and PO₄ tetrahedra sharing vertices. The second chain is built up from two edge-sharing Mn^IIO₆ octahedra leading to the formation of Mn^II₂O₁₀ dimers that are connected to two PO₄ tetrahedra by a common edge. These two types of chains are linked together by common vertices of PO₄ tetrahedra to form an open three-dimensional framework that delimits two types of tunnels parallel to [100] and [010] where the Ba^II ions are located (Fig. 2). The coordination sphere of the Ba^II ion is that of a bicapped trigonal prism.

Bond valence sum calculation (Brown & Altermatt, 1985) of BaMn^II₂Mn^III(PO₄)₃ resulted in expected values (in valence units) for the ions Ba1^II (2.26), Mn1^III (3.01), Mn2^II (2.09), P1^V (4.99), and P2^V (4.87). The three-dimensional framework of BaMn^II₂Mn^III(PO₄)₃ and its isotypic AMn^II₂Mn^III(PO₄)₃ (A = Pb, Sr) analogues, resemble that of the Ag₂M₃(HPO₄)(PO₄)₂ type with M = Ni or Co, whereby the two Ag⁺ cations in the channels are replaced by Ba^II, Pb^II or Sr^II.

2. Experimental

The hydrothermal treatment of a reaction mixture of barium, manganese and phosphate precursors in a proportion corresponding to the molar ratio Ba: Mn: P = 1: 3: 3 has allowed to isolate brown block-shaped crystals corresponding to the title compound as well as a parallelepipedic colourless crystals which were identified to be the known manganese phosphate Mn₅(HPO₄)₂(PO₄)₂^.4H₂O (Moore & Araki, 1973). The hydrothermal reaction was conducted in a 23 ml Teflon-lined autoclave, filled to 50% with distilled water and under autogeneous pressure at 463 K for five days.

3. Refinement

The highest peak and the deepest hole in the final Fourier map are at 0.82 Å and 1.00 Å away from Ba1.

Figures

Fig. 1.

The main building units of the crystal structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (i) x, -y + 1, -z; (ii) -x, y - 1/2, -z; (iii) x, y - 1/2, -z; (iv) -x, -y + 1, -z; (v) x, y, z - 1; (vi) -x, -y + 1/2, z - 1; (vii) -x, -y + 1/2, z; (viii) -x + 1/2, y - 1/2, z + 1/2; (ix) x - 1/2, -y + 1/2, -z + 1/2; (x) -x + 1/2, -y + 1/2, -z + 1/2; (xi) x - 1/2, y - 1/2, z + 1/2; (xii) -x, -y, -z + 1; (xiii) -x + 1/2, -y + 1, z + 1/2; (xiv) -x + 1/2, y, -z + 1/2.]

Fig. 2.

Polyhedral representation of BaMn3(PO4)3 with channels running parallel to [010].

Crystal data

BaMn3(PO4)3	F(000) = 1088
Mr = 587.07	Dx = 4.022 Mg m−3
Orthorhombic, Imma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -I 2b 2	Cell parameters from 811 reflections
a = 10.3038 (7) Å	θ = 3.4–30.5°
b = 14.0163 (11) Å	µ = 8.39 mm−1
c = 6.7126 (4) Å	T = 296 K
V = 969.44 (12) Å3	Block, brown
Z = 4	0.29 × 0.17 × 0.13 mm

Data collection

Bruker X8 APEX diffractometer	811 independent reflections
Radiation source: fine-focus sealed tube	732 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
φ and ω scans	θmax = 30.5°, θmin = 3.4°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −14→13
Tmin = 0.164, Tmax = 0.376	k = −19→20
3968 measured reflections	l = −9→7

Refinement

Refinement on F2	0 restraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F2 > 2σ(F2)] = 0.020	Secondary atom site location: difference Fourier map
wR(F2) = 0.055	w = 1/[σ2(Fo2) + (0.0353P)2] where P = (Fo2 + 2Fc2)/3
S = 1.09	(Δ/σ)max < 0.001
811 reflections	Δρmax = 1.86 e Å−3
53 parameters	Δρmin = −0.78 e Å−3

Special details

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

	x	y	z	Uiso*/Ueq
Ba1	0.0000	0.2500	−0.11499 (4)	0.01125 (10)
Mn1	0.0000	0.5000	0.5000	0.00794 (15)
Mn2	0.2500	0.36758 (4)	0.2500	0.01092 (13)
P1	0.0000	0.2500	0.39677 (16)	0.0078 (2)
P2	0.2500	0.57094 (6)	0.2500	0.00851 (17)
O1	0.0000	0.15998 (16)	0.5237 (4)	0.0115 (5)
O2	0.1185 (2)	0.2500	0.2553 (3)	0.0107 (4)
O3	0.21046 (19)	0.63040 (12)	0.0721 (3)	0.0133 (3)
O4	0.36337 (16)	0.49927 (12)	0.1983 (2)	0.0103 (3)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Ba1	0.01480 (16)	0.01187 (15)	0.00707 (14)	0.000	0.000	0.000
Mn1	0.0102 (3)	0.0081 (3)	0.0056 (3)	0.000	0.000	−0.0001 (2)
Mn2	0.0154 (3)	0.0063 (2)	0.0110 (2)	0.000	−0.00074 (18)	0.000
P1	0.0104 (5)	0.0065 (5)	0.0066 (5)	0.000	0.000	0.000
P2	0.0121 (4)	0.0064 (4)	0.0071 (3)	0.000	0.0010 (3)	0.000
O1	0.0166 (12)	0.0049 (9)	0.0129 (11)	0.000	0.000	0.0014 (8)
O2	0.0121 (11)	0.0103 (11)	0.0098 (10)	0.000	0.0035 (8)	0.000
O3	0.0183 (8)	0.0114 (8)	0.0100 (7)	0.0027 (6)	0.0006 (7)	0.0033 (6)
O4	0.0123 (8)	0.0087 (7)	0.0100 (7)	0.0014 (6)	0.0016 (6)	0.0009 (5)

Geometric parameters (Å, º)

Ba1—O1i	2.734 (2)	Mn2—O2	2.1337 (16)
Ba1—O1ii	2.734 (2)	Mn2—O2xiii	2.1337 (16)
Ba1—O3iii	2.7560 (18)	Mn2—O3iii	2.2006 (17)
Ba1—O3iv	2.7560 (18)	Mn2—O3ix	2.2006 (17)
Ba1—O3v	2.7560 (18)	Mn2—O4	2.2117 (17)
Ba1—O3vi	2.7560 (18)	Mn2—O4x	2.2117 (17)
Ba1—O2	2.769 (2)	P1—O1	1.523 (2)
Ba1—O2vii	2.769 (2)	P1—O1vii	1.523 (2)
Mn1—O4viii	1.9377 (17)	P1—O2vii	1.547 (2)
Mn1—O4ix	1.9377 (17)	P1—O2	1.547 (2)
Mn1—O4x	1.9377 (17)	P2—O3x	1.5119 (17)
Mn1—O4xi	1.9377 (17)	P2—O3	1.5119 (17)
Mn1—O1vii	2.248 (2)	P2—O4x	1.5792 (17)
Mn1—O1xii	2.248 (2)	P2—O4	1.5792 (17)
O1i—Ba1—O1ii	54.97 (9)	O4ix—Mn1—O1vii	87.51 (6)
O1i—Ba1—O3iii	111.92 (5)	O4x—Mn1—O1vii	92.49 (6)
O1ii—Ba1—O3iii	79.16 (5)	O4xi—Mn1—O1vii	87.51 (6)
O1i—Ba1—O3iv	79.16 (5)	O4viii—Mn1—O1xii	87.51 (6)
O1ii—Ba1—O3iv	111.92 (5)	O4ix—Mn1—O1xii	92.49 (6)
O3iii—Ba1—O3iv	168.02 (7)	O4x—Mn1—O1xii	87.51 (6)
O1i—Ba1—O3v	79.16 (5)	O4xi—Mn1—O1xii	92.49 (6)
O1ii—Ba1—O3v	111.92 (5)	O1vii—Mn1—O1xii	180.0
O3iii—Ba1—O3v	74.93 (8)	O2—Mn2—O2xiii	78.86 (10)
O3iv—Ba1—O3v	103.78 (8)	O2—Mn2—O3iii	84.77 (8)
O1i—Ba1—O3vi	111.92 (5)	O2xiii—Mn2—O3iii	96.38 (8)
O1ii—Ba1—O3vi	79.16 (5)	O2—Mn2—O3ix	96.38 (8)
O3iii—Ba1—O3vi	103.78 (8)	O2xiii—Mn2—O3ix	84.77 (8)
O3iv—Ba1—O3vi	74.93 (8)	O3iii—Mn2—O3ix	178.52 (9)
O3v—Ba1—O3vi	168.02 (7)	O2—Mn2—O4	169.28 (7)
O1i—Ba1—O2	142.77 (4)	O2xiii—Mn2—O4	107.86 (7)
O1ii—Ba1—O2	142.77 (4)	O3iii—Mn2—O4	86.16 (6)
O3iii—Ba1—O2	63.86 (5)	O3ix—Mn2—O4	92.61 (7)
O3iv—Ba1—O2	104.67 (5)	O2—Mn2—O4x	107.86 (7)
O3v—Ba1—O2	63.86 (5)	O2xiii—Mn2—O4x	169.28 (7)
O3vi—Ba1—O2	104.67 (5)	O3iii—Mn2—O4x	92.61 (7)
O1i—Ba1—O2vii	142.77 (4)	O3ix—Mn2—O4x	86.16 (6)
O1ii—Ba1—O2vii	142.77 (4)	O4—Mn2—O4x	66.86 (9)
O3iii—Ba1—O2vii	104.67 (5)	O1—P1—O1vii	111.94 (19)
O3iv—Ba1—O2vii	63.86 (5)	O1—P1—O2vii	110.09 (7)
O3v—Ba1—O2vii	104.67 (5)	O1vii—P1—O2vii	110.09 (7)
O3vi—Ba1—O2vii	63.86 (5)	O1—P1—O2	110.09 (7)
O2—Ba1—O2vii	52.33 (10)	O1vii—P1—O2	110.09 (7)
O4viii—Mn1—O4ix	180.0	O2vii—P1—O2	104.27 (19)
O4viii—Mn1—O4x	93.19 (10)	O3x—P2—O3	113.10 (14)
O4ix—Mn1—O4x	86.81 (10)	O3x—P2—O4x	112.12 (9)
O4viii—Mn1—O4xi	86.81 (10)	O3—P2—O4x	108.95 (10)
O4ix—Mn1—O4xi	93.19 (10)	O3x—P2—O4	108.95 (10)
O4x—Mn1—O4xi	180.0	O3—P2—O4	112.12 (9)
O4viii—Mn1—O1vii	92.49 (6)	O4x—P2—O4	100.99 (13)

Symmetry codes: (i) x, y, z−1; (ii) −x, −y+1/2, z−1; (iii) x, −y+1, −z; (iv) −x, y−1/2, −z; (v) x, y−1/2, −z; (vi) −x, −y+1, −z; (vii) −x, −y+1/2, z; (viii) x−1/2, y, −z+1/2; (ix) −x+1/2, −y+1, z+1/2; (x) −x+1/2, y, −z+1/2; (xi) x−1/2, −y+1, z+1/2; (xii) x, y+1/2, −z+1; (xiii) −x+1/2, −y+1/2, −z+1/2.