Dilead(II) trimanganese(II) bis(hydrogenphosphate) bis(phosphate)

Abstract

The title compound, Pb₂Mn₃(HPO₄)₂(PO₄)₂, was synthesized by a hydro­thermal method. All atoms are in general positions except for one Mn atom which is located on an inversion center. The framework of the structure is built up from PO₄ tetra­hedra and two types of MnO₆ octa­hedra, one almost ideal and the other very distorted with one very long Mn—O bond [2.610 (4) Å compared an average of 2.161 Å for the other bonds]. The centrosymetric octa­hedron is linked to two distorted MnO₆ octa­hedra by an edge common, forming infinite zigzag Mn₃O₁₄ chains running along the b axis. Adjacent chains are linked by PO₄ and PO₃(OH) tetra­hedra through vertices or by edge sharing, forming sheets perpendicular to [100]. The Pb²⁺ cations are sandwiched between the layers and ensure the cohesion of the crystal structure. O—H⋯O hydrogen bonding between the layers is also observed.

Related literature  

For properties of phosphates and their potential applications, see: Gao & Gao (2005 ▶); Viter & Nagornyi (2009 ▶); Clearfield (1988 ▶); Trad et al. (2010 ▶). For compounds with related structures, see: Assani et al. (2010 ▶, 2011a ▶,b ▶,c ▶, 2012 ▶); Effenberger (1999 ▶). For bond-valence analysis, see: Brown & Altermatt (1985 ▶).

Experimental  

Crystal data  

• Pb₂Mn₃(HPO₄)₂(PO₄)₂

• M _r = 961.10

• Monoclinic,

• a = 7.9449 (2) Å

• b = 8.8911 (2) Å

• c = 9.5718 (3) Å

• β = 100.917 (2)°

• V = 663.90 (3) ų

• Z = 2

• Mo Kα radiation

• μ = 28.63 mm⁻¹

• T = 296 K

• 0.18 × 0.12 × 0.08 mm

Data collection  

• Bruker X8 APEXII diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2003) ▶ T _min = 0.029, T _max = 0.117

• 8738 measured reflections

• 1225 independent reflections

• 1202 reflections with I > 2σ(I)

• R _int = 0.044

Refinement  

• R[F ² > 2σ(F ²)] = 0.020

• wR(F ²) = 0.051

• S = 1.10

• 1225 reflections

• 116 parameters

• H-atom parameters constrained

• Δρ_max = 1.37 e Å⁻³

• Δρ_min = −2.03 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); 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, 1997 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: PLATON (Spek, 2009 ▶) and publCIF (Westrip, 2010 ▶).

Supplementary Material

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O8—H8⋯O4	0.86	1.60	2.437 (5)	164
O8—H8⋯O1	0.86	2.76	3.393 (5)	132

supplementary crystallographic information

Comment

Owing to their remarkable variety of structures and to their outstanding potentialities in widespread applications such as catalysis (Viter & Nagornyi, 2009; Gao & Gao, 2005) and ion-exchangers (Clearfield, 1988) and in batteries performance (Trad et al., (2010)), transition metal based phosphates have received great attention and still remains in the forefront of the developed scientific axes in our laboratory. Within this family of compounds, the resulting anionic frameworks, generally constructed from the alternation of PO₄ tetrahedra connected to metal cations in different coordinate geometry MO_n (with n=4, 5 and 6), generate pores and channels offering suitable environment to accommodate different other cations. Accordingly, we have succeeded to isolate new silver metal based orthophosphates for instance, AgMg₃(PO₄)(HPO₄)₂ wich represent a new member of the well known alluaudite-like structure family (Assani et al. 2011a); silver (nickel or cobalt) phosphate, namely, Ag₂M₃(HPO₄)(PO₄)₂ with M=Ni, Co (Assani et al. 2011b; Assani et al. 2011c). Furthermore, a special attention have been paid to the ternary system MO—M'O—P₂O₅ with M=Ba, Ca, Cd, Pb and Sr and M'= transition metals, Mg and Zn. Our recent investigation has allowed to the isolate the compounds Ni₂Sr(PO₄)₂.2H₂O (Assani et al. 2010) and Co₂Pb(HPO₄)(PO₄)OH H₂O (Assani et al. 2012).

Inline with the focus of our research, the present paper aims to develop the hydrothermal synthesis and the structural characterization of a new layered lead manganese orthophosphate, namely, PbMn_1.5(PO₄)(HPO₄), which is characterized by Mn/P ratio =3/4, rarely encountered in the literature with the exception of some copper based orthophosphates, Pb₃Cu₃(PO₄)₄ and Sr₃Cu₃(PO₄)₄ (Effenberger 1999).

A partial three-dimensional plot of the crystal structure of PbMn_1.5(PO₄)(HPO₄) is represented in Fig. 1. A l l atoms of this structure are in general positions, except one manganese Mn1 located in symmetry center (1) 2a (0 0 0; 0 1/2 1/2) of P2₁/c space group. The network is built up from two different types of polyhedra more or less distorted, viz. PO₄, HPO₄ tetrahedra and Mn1O₆ (1 symmetry), Mn2O₆ octahedra. Moreover, the edge-sharing Mn1O₆ and Mn2O₅(OH) octahedra form an infinite zigzag chains ¹∞ [Mn₃O₁₄] running parallel to [010], as shown in Fig. 2. Adjacent chains are connected by PO₄ and HPO₄ tetrahedra via vertices in the way to build layers parallel to (100). These layers are in turn linked by Pb²⁺ cations as shown in Fig.2. The strong hydrogen bonding between the layers is also involved in the stability of this structure (Fig. 2 and Table 2).

Bond valence sum calculations (Brown & Altermatt, 1985) for Pb1²⁺, Mn1²⁺, Mb2²⁺, P1⁵⁺ and P2⁵⁺ ions are as expected, viz. 1.82, 2.13, 1.97, 4.95 and 5.01 valence units, respectively. The values of the bond valence sums calculated for all oxygen atoms are between 1.93 and 2.05 except O4 and O8 which shown low values: 1.62 and 1.50 respectively. These atoms are considerably undersaturated and thus act as an acceptor with a very short H-bond (Table 2, Fig.1).

Experimental

The crystals of the title compound is isolated from the hydrothermal treatment of the reaction mixture of lead oxide, metallic manganese and 85wt% phosphoric acid in a proportion corresponding to the molar ratio Pb:Mn:P = 1,5: 3:3.

The hydrothermal reaction was conducted in a 23 ml Teflon-lined autoclave, filled to 50% with distilled water and under autogeneous pressure at 483 K for twenty hours. After being filtered off, washed with deionized water and air dried, the reaction product consists of a light brown solid and colorless sheet shaped crystals corresponding to the title compound.

Refinement

The O-bound H atoms were initially located in a difference map and refined with O—H distance restraints of 0.86 (1). In the last cycle they were refined in the riding model approximation with U_iso(H) set to 1.2U_eq(O). The highest peak and the deepest hole in the final Fourier map are at 0.62 Å and 0.67 Å, respectively, from Pb1. The not significants bonds and angles were removed from the CIF file.

Figures

Fig. 1.

A partial three-dimensional plot of the crystal structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level. Symmetry codes:(i) x, -y + 3/2, z + 1/2; (ii) -x + 1, -y + 1, -z + 1; (iii) -x + 1, y - 1/2, -z + 3/2; (iv) -x, y - 1/2, -z + 1/2; (v) x - 1, y, z; (vi) -x, -y + 1, -z + 1; (vii) x, -y + 1/2, z + 1/2; (viii) x, -y + 1/2, z - 1/2; (ix) -x, y + 1/2, -z + 1/2; (x) x, -y + 3/2, z - 1/2; (xi) -x + 1, y + 1/2, -z + 3/2; (xii) x + 1, y, z.

Fig. 2.

A three-dimensional polyhedral view of the crystal structure of the PbMn1.5(PO4)(HPO4), showing the stacking of layers along the a axis and the hydrogen bonding scheme (dashed lines).

Crystal data

Pb2Mn3(HPO4)2(PO4)2	F(000) = 858
Mr = 961.10	Dx = 4.808 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1225 reflections
a = 7.9449 (2) Å	θ = 2.6–25.4°
b = 8.8911 (2) Å	µ = 28.63 mm−1
c = 9.5718 (3) Å	T = 296 K
β = 100.917 (2)°	Prism, pink
V = 663.90 (3) Å3	0.18 × 0.12 × 0.08 mm
Z = 2

Data collection

Bruker X8 APEXII diffractometer	1225 independent reflections
Radiation source: fine-focus sealed tube	1202 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.044
φ and ω scans	θmax = 25.4°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −9→9
Tmin = 0.029, Tmax = 0.117	k = −10→10
8738 measured reflections	l = −11→11

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.020	H-atom parameters constrained
wR(F2) = 0.051	w = 1/[σ2(Fo2) + (0.0232P)2 + 2.912P] where P = (Fo2 + 2Fc2)/3
S = 1.10	(Δ/σ)max = 0.001
1225 reflections	Δρmax = 1.37 e Å−3
116 parameters	Δρmin = −2.03 e Å−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0091 (4)

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 > 2σ(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
Pb1	0.41097 (3)	0.52400 (2)	0.75343 (2)	0.01734 (13)
Mn1	0.0000	0.5000	0.5000	0.0091 (2)
Mn2	0.10770 (9)	0.13892 (8)	0.59303 (7)	0.00981 (19)
P1	0.14019 (16)	0.70441 (14)	0.23105 (12)	0.0076 (3)
P2	0.65619 (16)	0.70724 (14)	0.56583 (12)	0.0087 (3)
O1	0.0496 (5)	0.6808 (4)	0.3570 (4)	0.0123 (7)
O2	0.0740 (5)	0.5969 (4)	0.1080 (3)	0.0122 (7)
O3	0.1156 (5)	0.8690 (4)	0.1828 (4)	0.0127 (7)
O4	0.3370 (5)	0.6828 (4)	0.2816 (4)	0.0133 (7)
O5	0.7064 (5)	0.6754 (5)	0.7236 (4)	0.0208 (9)
O6	0.7536 (5)	0.6118 (4)	0.4742 (4)	0.0152 (8)
O7	0.6777 (5)	0.8718 (4)	0.5276 (4)	0.0212 (9)
O8	0.4617 (5)	0.6642 (4)	0.5341 (4)	0.0146 (7)
H8	0.4002	0.6667	0.4499	0.022*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Pb1	0.01783 (17)	0.01676 (17)	0.01923 (17)	0.00271 (7)	0.00812 (10)	0.00201 (7)
Mn1	0.0108 (6)	0.0084 (5)	0.0080 (5)	0.0006 (4)	0.0018 (4)	0.0002 (4)
Mn2	0.0096 (4)	0.0107 (4)	0.0082 (4)	0.0003 (3)	−0.0008 (3)	−0.0006 (3)
P1	0.0080 (6)	0.0090 (6)	0.0055 (6)	−0.0004 (5)	0.0003 (5)	0.0003 (4)
P2	0.0080 (6)	0.0111 (6)	0.0067 (6)	−0.0007 (5)	0.0009 (5)	−0.0005 (4)
O1	0.0154 (19)	0.0110 (17)	0.0120 (17)	−0.0005 (14)	0.0068 (14)	0.0016 (13)
O2	0.0154 (19)	0.0111 (17)	0.0076 (16)	0.0002 (14)	−0.0045 (14)	−0.0020 (13)
O3	0.0154 (19)	0.0099 (17)	0.0120 (17)	0.0005 (14)	0.0008 (14)	0.0026 (14)
O4	0.0083 (18)	0.0234 (19)	0.0078 (16)	0.0002 (14)	0.0004 (13)	−0.0002 (14)
O5	0.015 (2)	0.038 (2)	0.0076 (18)	0.0013 (17)	−0.0021 (14)	0.0035 (16)
O6	0.0113 (18)	0.0200 (19)	0.0153 (17)	0.0061 (15)	0.0048 (14)	0.0015 (15)
O7	0.030 (2)	0.0118 (18)	0.026 (2)	−0.0036 (16)	0.0151 (18)	−0.0013 (16)
O8	0.0087 (17)	0.0261 (19)	0.0079 (16)	−0.0034 (15)	−0.0012 (14)	0.0016 (15)

Geometric parameters (Å, º)

Pb1—O3i	2.504 (4)	P1—O3	1.536 (3)
Pb1—O8	2.539 (4)	P1—O4	1.559 (4)
Pb1—O6ii	2.614 (4)	P2—O5	1.514 (4)
Pb1—O4i	2.697 (4)	P2—O7	1.526 (4)
Pb1—O7iii	2.698 (4)	P2—O6	1.532 (4)
Pb1—O5	2.767 (4)	P2—O8	1.565 (4)
Pb1—O4ii	2.785 (4)	O1—Mn2vi	2.141 (4)
Mn1—O3iv	2.157 (3)	O2—Mn2viii	2.122 (4)
Mn1—O3i	2.157 (3)	O2—Mn2ix	2.208 (3)
Mn1—O6ii	2.168 (3)	O3—Mn1ix	2.157 (3)
Mn1—O6v	2.168 (3)	O3—Pb1x	2.504 (4)
Mn1—O1	2.195 (3)	O4—Pb1x	2.697 (4)
Mn1—O1vi	2.195 (3)	O4—Pb1ii	2.785 (4)
Mn2—O5iii	2.094 (4)	O5—Mn2xi	2.094 (4)
Mn2—O2vii	2.122 (4)	O6—Mn1xii	2.168 (3)
Mn2—O1vi	2.141 (4)	O6—Mn2ii	2.610 (4)
Mn2—O2iv	2.208 (3)	O6—Pb1ii	2.614 (4)
Mn2—O7ii	2.235 (4)	O7—Mn2ii	2.235 (4)
Mn2—O6ii	2.610 (4)	O7—Pb1xi	2.698 (4)
P1—O2	1.530 (3)	O8—H8	0.8600
P1—O1	1.531 (3)
O3i—Pb1—O8	82.97 (11)	O3i—Mn1—O1vi	89.35 (13)
O3i—Pb1—O6ii	69.84 (11)	O6ii—Mn1—O1vi	81.84 (13)
O8—Pb1—O6ii	70.75 (11)	O6v—Mn1—O1vi	98.16 (13)
O3i—Pb1—O4i	56.56 (11)	O1—Mn1—O1vi	180.000 (1)
O8—Pb1—O4i	71.32 (11)	O5iii—Mn2—O2vii	100.04 (15)
O6ii—Pb1—O4i	116.47 (11)	O5iii—Mn2—O1vi	92.62 (15)
O3i—Pb1—O7iii	91.78 (12)	O2vii—Mn2—O1vi	129.62 (14)
O8—Pb1—O7iii	173.95 (12)	O5iii—Mn2—O2iv	176.09 (15)
O6ii—Pb1—O7iii	104.65 (12)	O2vii—Mn2—O2iv	79.73 (13)
O4i—Pb1—O7iii	108.25 (11)	O1vi—Mn2—O2iv	90.49 (14)
O3i—Pb1—O5	123.87 (12)	O5iii—Mn2—O7ii	87.34 (15)
O8—Pb1—O5	53.50 (11)	O2vii—Mn2—O7ii	96.38 (14)
O6ii—Pb1—O5	116.03 (11)	O1vi—Mn2—O7ii	133.01 (14)
O4i—Pb1—O5	75.23 (12)	O2iv—Mn2—O7ii	88.81 (14)
O7iii—Pb1—O5	132.49 (12)	O5iii—Mn2—O6ii	79.12 (14)
O3i—Pb1—O4ii	151.26 (10)	O2vii—Mn2—O6ii	157.01 (13)
O8—Pb1—O4ii	89.67 (11)	O1vi—Mn2—O6ii	73.21 (12)
O6ii—Pb1—O4ii	81.50 (10)	O2iv—Mn2—O6ii	99.54 (12)
O4i—Pb1—O4ii	145.63 (8)	O7ii—Mn2—O6ii	60.65 (12)
O7iii—Pb1—O4ii	93.55 (11)	O2—P1—O1	112.1 (2)
O5—Pb1—O4ii	70.46 (12)	O2—P1—O3	111.0 (2)
O3iv—Mn1—O3i	180.000 (1)	O1—P1—O3	108.4 (2)
O3iv—Mn1—O6ii	94.68 (14)	O2—P1—O4	109.9 (2)
O3i—Mn1—O6ii	85.32 (14)	O1—P1—O4	109.4 (2)
O3iv—Mn1—O6v	85.32 (14)	O3—P1—O4	105.9 (2)
O3i—Mn1—O6v	94.68 (14)	O5—P2—O7	113.5 (2)
O6ii—Mn1—O6v	180.00 (19)	O5—P2—O6	113.7 (2)
O3iv—Mn1—O1	89.35 (13)	O7—P2—O6	107.6 (2)
O3i—Mn1—O1	90.65 (13)	O5—P2—O8	102.2 (2)
O6ii—Mn1—O1	98.16 (13)	O7—P2—O8	109.8 (2)
O6v—Mn1—O1	81.84 (13)	O6—P2—O8	109.9 (2)
O3iv—Mn1—O1vi	90.65 (13)

Symmetry codes: (i) x, −y+3/2, z+1/2; (ii) −x+1, −y+1, −z+1; (iii) −x+1, y−1/2, −z+3/2; (iv) −x, y−1/2, −z+1/2; (v) x−1, y, z; (vi) −x, −y+1, −z+1; (vii) x, −y+1/2, z+1/2; (viii) x, −y+1/2, z−1/2; (ix) −x, y+1/2, −z+1/2; (x) x, −y+3/2, z−1/2; (xi) −x+1, y+1/2, −z+3/2; (xii) x+1, y, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O8—H8···O4	0.86	1.60	2.437 (5)	164
O8—H8···O1	0.86	2.76	3.393 (5)	132