KPr(PO3)4

Oudahmane, A.; Daoud, M.; Tanouti, B.; Avignant, D.; Zambon, D.

doi:10.1107/S1600536810026942

inorganic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 66| Part 8| August 2010| Pages i59-i60

https://doi.org/10.1107/S1600536810026942

Open

access

KPr(PO₃)₄

Abdelghani Oudahmane,^a Mohamed Daoud,^a Boumediene Tanouti,^a Daniel Avignant ^b ^* and Daniel Zambon ^b

^aUniversité Cadi Ayyad, Laboratoire de la Matière Condensée et de l'Environnement, Faculté des Sciences Semlalia, Département de Chimie, BP 2390, 40000 Marrakech, Morocco, and ^bUniversité Blaise Pascal, Laboratoire des Matériaux Inorganiques, UMR CNRS 6002, 24 Avenue des Landais, 63177 Aubière, France
^*Correspondence e-mail: daniel.avignant@univ-bpclermont.fr

(Received 1 July 2010; accepted 7 July 2010; online 14 July 2010)

Single crystals of the title compound, potassium praseodymium(III) polyphosphate, were obtained by solid-state reaction. The monoclinic non-centrosymmetric structure is isotypic with all other KLn(PO₃)₄ analogues from Ln = La to Er, inclusive. The crystal structure of these long-chain polyphosphates is built up from infinite crenelated polyphosphate chains of corner-sharing PO₄ tetrahedra with a repeating unit of four tetrahedra. These chains, running along [100], are arranged in a pseudo-tetragonal rod packing and are further linked by isolated PrO₈ square antiprisms [Pr—O = 2.3787 (9)–2.5091 (8) Å], forming a three-dimensional framework. The K⁺ ions reside in channels parallel to [010] and exhibit a highly distorted coordination sphere by eight O atoms at distances ranging from 2.7908 (9) to 3.1924 (11) Å.

Related literature

Long-chain polyphosphates with general formula A^IB^III(PO₃)₄ have been classified into seven structural types, labelled from I to VII (Jaoudi et al., 2003 ). All KLn(PO₃)₄ polyphosphates (Ln is a trivalent rare earth element) reported up to now adopt type III except for KYb(PO₃)₄ (Palkina et al., 1981 ). For corresponding isotypic crystal structures, see: Zhu et al. (2009 ) for Ce and Eu; Horchani-Naifer et al. (2008 ) for Y; Parreu et al. (2006 ) for Gd and Nd; Xing et al. (1987 ) for Tb; Ninghai et al. (1984 ) for Eu; Lin et al. (1983 ) for La; Krutik et al. (1980 ) for Er; Hong et al. (1975 ) for Nd. For a review of the crystal chemistry of phosphates, see: Durif (1995 ). For the cyclophosphate structure with the same composition, KPr(PO₃)₄, see: Zhou et al. (1987 ).

Experimental

Crystal data

KPr(PO3)₄
M_r = 495.89
Monoclinic, P 2₁
a = 7.2872 (2) Å
b = 8.4570 (3) Å
c = 8.0268 (2) Å
β = 91.994 (1)°
V = 494.37 (3) Å³
Z = 2
Mo Kα radiation
μ = 6.06 mm⁻¹
T = 296 K
0.29 × 0.21 × 0.16 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ) T_min = 0.448, T_max = 0.751
45940 measured reflections
13443 independent reflections
13257 reflections with I > 2σ(I)
R_int = 0.034

Refinement

R[F² > 2σ(F²)] = 0.018
wR(F²) = 0.043
S = 1.07
13443 reflections
164 parameters
1 restraint
Δρ_max = 2.86 e Å⁻³
Δρ_min = −2.42 e Å⁻³
Absolute structure: Flack (1983 ), 6278 Friedel pairs
Flack parameter: 0.022 (3)

Table 1
Selected bond lengths (Å)

P1—O6	1.4841 (8)
P1—O12	1.4850 (8)
P1—O5	1.5881 (7)
P1—O10	1.5887 (9)
P2—O11	1.4810 (9)
P2—O7ⁱ	1.4822 (8)
P2—O1	1.5926 (8)
P2—O2	1.5941 (8)
P3—O3ⁱⁱ	1.4806 (8)
P3—O4	1.4832 (8)
P3—O5	1.5902 (8)
P3—O1ⁱⁱⁱ	1.5980 (8)
P4—O8^iv	1.4777 (8)
P4—O9^v	1.4829 (8)
P4—O2	1.5874 (8)
P4—O10	1.5973 (9)
Symmetry codes: (i) $[-x+1, y+{\script{1\over 2}}, -z+1]$ ; (ii) $[-x, y+{\script{1\over 2}}, -z+1]$ ; (iii) x-1, y, z; (iv) $[-x+1, y-{\script{1\over 2}}, -z+1]$ ; (v) x, y, z-1.

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: CaRine (Boudias & Monceau, 1998 ) and ORTEP-3 for Windows (Farrugia, 1997 ); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536810026942/wm2370sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810026942/wm2370Isup2.hkl

checkCIF report

Comment top

Long chains polyphosphates with general formula A^IB^III(PO₃)₄ have been classified into seven structural types, labelled from I to VII (Durif, 1995; Jaoudi et al. 2003). All long-chains polyphosphates of formula KLn(PO₃)₄ (Ln = rare earth elements) reported up to now (Zhu et al., 2009; Horchani-Naifer et al., 2008; Parreu et al., 2006; Xing et al., 1987; Ninghai et al., 1984; Lin et al., 1983; Krutik et al., 1980; Hong et al., 1975) adopt type III except for KYb(PO₃)₄ (Palkina et al. 1981) which is the only presently known member of type V. Most of these potassium polyphosphates are dimorphic and crystallize with both the type III and the type IV polymorphs. KCe(PO₃)₄ which has been shown to crystallize with either the type II and the type III is the first exception. The second exception is concerned with the Er member of this series presenting the type VII polymorph besides both type III and type IV polymorphs. Moreover, type III long-chain polyphosphates do not exist for monovalent cations other than K⁺. The structure of the title compound also fits in this type III isotypic series.

The crystal structure of the title compound is built from crenelated chains with a repeating unit of four corner-sharing tetrahedra, as displayed in Fig. 1. The chains are further linked by isolated PrO₈ square antiprisms to form the three-dimensional framework. Each PrO₈ polyhedron (Pr—O distances range from 2.3787 (9) to 2.5091 (8) Å) is connected through vertices to four (PO₃)_∞ chains stacked in a pseudo-tetragonal rod packing as shown in Fig. 2. Figure 2 also shows that within this pseudo-tetragonal rod packing, two adjacent chains are twisted by ca. 90 ° whereas two opposite chains are parallel. The relative disposition of the chains running along the [100] direction accounts for the strong non-centrosymmetric character of the structure. Figure 3 displays details of the connections between the PrO₈ square antiprisms and the four chains surrounding each antiprism. One of the four chains (labelled C₁) is attached in a tridentate fashion on a triangular face of the square antiprism whereas the opposite and parallel chain (labelled C₂) is connected only through a vertex (Fig. 3a). The two other chains which are adjacent to the first one are attached in a bidentate fashion. The first of these two chains (labelled C₃) is linked through a bidentate diphosphate group attached on one side of one square face of the square antiprism (Fig. 3b). The second chain (labelled C₄) is connected at the ends of one diagonal of the second square face of the antiprism (Fig. 3c) through corners of the terminal PO₄ groups of the crenel-shaped tetraphosphate group corresponding to the repeating unit of the chain. This polyhedral linkage delimits channels running along [010] where the K⁺ions lie in a highly distorted environment defined by eight oxygen atoms at distances ranging from 2.7908 (9) to 3.1924 (11) Å.

For the cyclophosphate structure with the same composition KPr(PO₃)₄, see: (Zhou et al., 1987).

Related literature top

Long-chain polyphosphates with general formula A^IB^III(PO₃)₄ have been classified into seven structural types, labelled from I to VII (Jaoudi et al., 2003). All KLn(PO₃)₄ polyphosphates (Ln is a trivalent rare earth element) reported up to now adopt type III except for KYb(PO₃)₄ (Palkina et al., 1981). For corresponding isotypic crystal structures, see: Zhu et al. (2009) for Ce and Eu; Horchani-Naifer et al. (2008) for Y; Parreu et al. (2006) for Gd and Nd; Xing et al. (1987) for Tb; Ninghai et al. (1984) for Eu; Lin et al. (1983) for La; Krutik et al. (1980) for Er; Hong et al. (1975) for Nd. For a review of the crystal chemistry of phosphates, see: Durif (1995). For the cyclophosphate structure with the same composition, KPr(PO₃)₄, see: Zhou et al. (1987).

Experimental top

Crystals of the title compound were synthesized by reacting Pr₆O₁₁ with (NH₄)H₂PO₄ and K₂CO₃ in a platinum crucible. A mixture of these reagents in the molar ratio 14: 66: 20 was used for the synthesis. The mixture has first been heated at 473 K for 12 h and then the temperature has been increased up to 573 K and maintained for 12 h before to be raised at 853 K and kept for 24 additional hours. At the end of this heating step, the muffle furnace was cooled down first to 673 K at the rate of 2 K h^-1 and subsequently to room temperature by switching the power off. Single crystals were extracted from the batch by leaching with hot water.

Structure description top

For the cyclophosphate structure with the same composition KPr(PO₃)₄, see: (Zhou et al., 1987).

Long-chain polyphosphates with general formula A^IB^III(PO₃)₄ have been classified into seven structural types, labelled from I to VII (Jaoudi et al., 2003). All KLn(PO₃)₄ polyphosphates (Ln is a trivalent rare earth element) reported up to now adopt type III except for KYb(PO₃)₄ (Palkina et al., 1981). For corresponding isotypic crystal structures, see: Zhu et al. (2009) for Ce and Eu; Horchani-Naifer et al. (2008) for Y; Parreu et al. (2006) for Gd and Nd; Xing et al. (1987) for Tb; Ninghai et al. (1984) for Eu; Lin et al. (1983) for La; Krutik et al. (1980) for Er; Hong et al. (1975) for Nd. For a review of the crystal chemistry of phosphates, see: Durif (1995). For the cyclophosphate structure with the same composition, KPr(PO₃)₄, see: Zhou et al. (1987).

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: CaRine (Boudias & Monceau, 1998) and ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. View of the repeating unit of the (PO₃)_∞ chains. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (vi) -x + 1, y + 1/2, -z + 1; (vii) x, y, z - 1; (viii) -x, y + 1/2, -z + 1; (ix) x - 1, y, z.]
	Fig. 2. Projection along [100] showing the pseudo-tetragonal rod packing of the infinite (PO₃) chains.
	Fig. 3. Details of the connections between the (PO₃)_∞ chains and the PrO₈ square antiprisms: a) view showing the tridentate attachement of one chain (C₁) and the connection of the second chain (C₂) parallel and opposite to the first one. b) view showing the bidentate attachement of the third chain (C₃) adjacent and orthogonal to the first one. c) view showing the bidentate attachement of the fourth chain (C₄) also orthogonal and adjacent to the first one.

Potassium praseodymium polyphosphate top

Crystal data top

KPr(PO3)₄	F(000) = 468
M_r = 495.89	D_x = 3.331 Mg m⁻³
Monoclinic, P2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 9960 reflections
a = 7.2872 (2) Å	θ = 2.8–57.3°
b = 8.4570 (3) Å	µ = 6.06 mm⁻¹
c = 8.0268 (2) Å	T = 296 K
β = 91.994 (1)°	Prism, green
V = 494.37 (3) Å³	0.29 × 0.21 × 0.16 mm
Z = 2

Data collection top

Bruker APEXII CCD diffractometer	13443 independent reflections
Radiation source: fine-focus sealed tube	13257 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.034
Detector resolution: 8.3333 pixels mm^-1	θ_max = 57.4°, θ_min = 3.7°
ω and φ scans	h = −17→17
Absorption correction: multi-scan (SADABS; Bruker, 2008)	k = −19→20
T_min = 0.448, T_max = 0.751	l = −18→18
45940 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	w = 1/[σ²(F_o²) + (0.P)² + 0.0715P] where P = (F_o² + 2F_c²)/3
R[F² > 2σ(F²)] = 0.018	(Δ/σ)_max = 0.004
wR(F²) = 0.043	Δρ_max = 2.86 e Å⁻³
S = 1.07	Δρ_min = −2.42 e Å⁻³
13443 reflections	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
164 parameters	Extinction coefficient: 0.0305 (6)
1 restraint	Absolute structure: Flack (1983), 6278 Friedel pairs
0 constraints	Absolute structure parameter: 0.022 (3)
Primary atom site location: structure-invariant direct methods

Crystal data top

KPr(PO3)₄	V = 494.37 (3) Å³
M_r = 495.89	Z = 2
Monoclinic, P2₁	Mo Kα radiation
a = 7.2872 (2) Å	µ = 6.06 mm⁻¹
b = 8.4570 (3) Å	T = 296 K
c = 8.0268 (2) Å	0.29 × 0.21 × 0.16 mm
β = 91.994 (1)°

Data collection top

Bruker APEXII CCD diffractometer	13443 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2008)	13257 reflections with I > 2σ(I)
T_min = 0.448, T_max = 0.751	R_int = 0.034
45940 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.018	1 restraint
wR(F²) = 0.043	Δρ_max = 2.86 e Å⁻³
S = 1.07	Δρ_min = −2.42 e Å⁻³
13443 reflections	Absolute structure: Flack (1983), 6278 Friedel pairs
164 parameters	Absolute structure parameter: 0.022 (3)

Special details top

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

	x	y	z	U_iso*/U_eq
K	0.77227 (5)	0.31500 (7)	0.72001 (4)	0.02909 (8)
Pr	0.265282 (4)	0.119995 (8)	0.757982 (4)	0.00552 (1)
P1	0.50137 (3)	0.26677 (3)	0.38019 (3)	0.00690 (3)
P2	0.93476 (3)	0.24280 (3)	0.09865 (3)	0.00685 (3)
P3	0.12252 (3)	0.37267 (3)	0.39531 (3)	0.00674 (3)
P4	0.60346 (3)	0.04117 (3)	0.10444 (3)	0.00675 (3)
O1	1.04301 (12)	0.23711 (10)	0.27436 (11)	0.01360 (11)
O2	0.81354 (11)	0.08886 (10)	0.12702 (13)	0.01412 (12)
O3	−0.03801 (11)	0.02642 (9)	0.65100 (11)	0.01191 (10)
O4	0.11151 (11)	0.31458 (11)	0.56903 (9)	0.01188 (10)
O5	0.33093 (10)	0.38001 (9)	0.34329 (10)	0.01061 (9)
O6	0.66909 (10)	0.36646 (10)	0.38630 (10)	0.01127 (9)
O7	0.18250 (12)	−0.11539 (10)	0.92653 (10)	0.01172 (10)
O8	0.41427 (12)	0.38104 (10)	0.82424 (13)	0.01527 (12)
O9	0.53826 (12)	0.07174 (11)	0.93036 (10)	0.01395 (12)
O10	0.49263 (14)	0.16280 (13)	0.21526 (13)	0.01754 (15)
O11	1.06463 (16)	0.21154 (13)	−0.03535 (13)	0.01866 (16)
O12	0.46952 (13)	0.16652 (11)	0.52829 (11)	0.01411 (12)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
K	0.01717 (11)	0.0542 (3)	0.01579 (10)	0.00955 (13)	−0.00159 (8)	−0.00090 (12)
Pr	0.00546 (1)	0.00563 (1)	0.00548 (1)	−0.00032 (1)	0.00021 (1)	0.00006 (1)
P1	0.00666 (7)	0.00665 (7)	0.00750 (7)	0.00002 (5)	0.00174 (5)	0.00055 (5)
P2	0.00649 (6)	0.00695 (7)	0.00716 (7)	−0.00010 (5)	0.00069 (5)	−0.00144 (5)
P3	0.00623 (6)	0.00685 (7)	0.00704 (7)	0.00079 (5)	−0.00105 (5)	0.00031 (5)
P4	0.00704 (7)	0.00576 (6)	0.00735 (7)	−0.00051 (5)	−0.00141 (5)	−0.00019 (5)
O1	0.0159 (3)	0.0098 (2)	0.0145 (3)	0.0010 (2)	−0.0082 (2)	−0.00244 (18)
O2	0.0083 (2)	0.0108 (2)	0.0229 (3)	−0.00354 (17)	−0.0037 (2)	0.0027 (2)
O3	0.0102 (2)	0.0084 (2)	0.0168 (3)	−0.00284 (17)	−0.00320 (19)	−0.00037 (18)
O4	0.0114 (2)	0.0160 (3)	0.0082 (2)	0.0013 (2)	0.00038 (16)	0.00301 (18)
O5	0.00730 (18)	0.0111 (2)	0.0135 (2)	0.00173 (16)	0.00166 (16)	0.00354 (18)
O6	0.00779 (19)	0.0116 (2)	0.0145 (2)	−0.00191 (17)	0.00084 (16)	0.00167 (19)
O7	0.0141 (2)	0.0103 (2)	0.0106 (2)	−0.00433 (19)	−0.00116 (18)	0.00117 (17)
O8	0.0131 (3)	0.0090 (2)	0.0235 (4)	0.00183 (19)	−0.0015 (2)	−0.0067 (2)
O9	0.0143 (3)	0.0186 (3)	0.0087 (2)	0.0028 (2)	−0.00406 (18)	0.0001 (2)
O10	0.0157 (3)	0.0201 (3)	0.0169 (3)	0.0020 (3)	0.0016 (2)	−0.0106 (3)
O11	0.0206 (4)	0.0191 (3)	0.0171 (3)	0.0030 (3)	0.0121 (3)	−0.0029 (3)
O12	0.0141 (3)	0.0144 (3)	0.0142 (3)	0.0033 (2)	0.0059 (2)	0.0074 (2)

Geometric parameters (Å, º) top

K—O4ⁱ	2.7908 (9)	P2—O7^vi	1.4822 (8)
K—O6	2.7909 (9)	P2—O1	1.5926 (8)
K—O8	2.8231 (10)	P2—O2	1.5941 (8)
K—O3ⁱ	2.8684 (10)	P2—K^vii	3.2805 (4)
K—O7ⁱⁱ	2.9050 (9)	P3—O3^viii	1.4806 (8)
K—O12	2.9285 (11)	P3—O4	1.4832 (8)
K—O11ⁱⁱⁱ	2.9781 (13)	P3—O5	1.5902 (8)
K—O9	3.1924 (11)	P3—O1^ix	1.5980 (8)
K—P2ⁱⁱⁱ	3.2805 (4)	P4—O8^v	1.4777 (8)
K—P1	3.3360 (4)	P4—O9^vii	1.4829 (8)
Pr—O11^iv	2.3787 (9)	P4—O2	1.5874 (8)
Pr—O9	2.4180 (8)	P4—O10	1.5973 (9)
Pr—O12	2.4414 (8)	O1—P3ⁱ	1.5980 (8)
Pr—O3	2.4731 (7)	O3—P3^x	1.4806 (8)
Pr—O4	2.4791 (8)	O3—K^ix	2.8684 (10)
Pr—O6^v	2.4912 (8)	O4—K^ix	2.7908 (9)
Pr—O7	2.4928 (8)	O6—Pr^vi	2.4912 (8)
Pr—O8	2.5091 (8)	O7—P2^v	1.4822 (8)
P1—O6	1.4841 (8)	O7—K^xi	2.9051 (9)
P1—O12	1.4850 (8)	O8—P4^vi	1.4776 (8)
P1—O5	1.5881 (7)	O9—P4ⁱⁱⁱ	1.4829 (8)
P1—O10	1.5887 (9)	O11—Pr^xii	2.3787 (9)
P2—O11	1.4810 (9)	O11—K^vii	2.9782 (13)

O4ⁱ—K—O6	78.26 (2)	O12—Pr—O8	75.38 (3)
O4ⁱ—K—O8	166.08 (3)	O3—Pr—O8	136.89 (3)
O6—K—O8	91.87 (3)	O4—Pr—O8	74.26 (3)
O4ⁱ—K—O3ⁱ	58.32 (3)	O6^v—Pr—O8	140.10 (3)
O6—K—O3ⁱ	93.61 (3)	O7—Pr—O8	134.32 (3)
O8—K—O3ⁱ	133.01 (3)	O11^iv—Pr—K^ix	48.64 (3)
O4ⁱ—K—O7ⁱⁱ	110.62 (3)	O9—Pr—K^ix	147.29 (2)
O6—K—O7ⁱⁱ	157.42 (3)	O12—Pr—K^ix	116.78 (2)
O8—K—O7ⁱⁱ	75.23 (3)	O3—Pr—K^ix	46.23 (2)
O3ⁱ—K—O7ⁱⁱ	108.78 (3)	O4—Pr—K^ix	44.44 (2)
O4ⁱ—K—O12	115.71 (3)	O6^v—Pr—K^ix	120.771 (19)
O6—K—O12	52.38 (2)	O7—Pr—K^ix	97.96 (2)
O8—K—O12	63.48 (3)	O8—Pr—K^ix	91.99 (2)
O3ⁱ—K—O12	83.86 (3)	O11^iv—Pr—K	120.16 (3)
O7ⁱⁱ—K—O12	131.14 (3)	O9—Pr—K	51.68 (2)
O4ⁱ—K—O11ⁱⁱⁱ	70.23 (2)	O12—Pr—K	45.47 (3)
O6—K—O11ⁱⁱⁱ	147.28 (3)	O3—Pr—K	155.08 (2)
O8—K—O11ⁱⁱⁱ	120.66 (3)	O4—Pr—K	94.44 (2)
O3ⁱ—K—O11ⁱⁱⁱ	62.54 (3)	O6^v—Pr—K	97.156 (19)
O7ⁱⁱ—K—O11ⁱⁱⁱ	50.31 (2)	O7—Pr—K	127.02 (2)
O12—K—O11ⁱⁱⁱ	136.81 (3)	O8—Pr—K	43.25 (2)
O4ⁱ—K—O9	136.58 (3)	K^ix—Pr—K	130.558 (15)
O6—K—O9	118.49 (3)	O6—P1—O12	116.70 (5)
O8—K—O9	56.95 (3)	O6—P1—O5	107.54 (5)
O3ⁱ—K—O9	79.85 (3)	O12—P1—O5	110.52 (5)
O7ⁱⁱ—K—O9	70.04 (3)	O6—P1—O10	110.55 (5)
O12—K—O9	66.11 (2)	O12—P1—O10	110.38 (6)
O11ⁱⁱⁱ—K—O9	81.08 (3)	O5—P1—O10	99.78 (5)
O4ⁱ—K—P2ⁱⁱⁱ	96.054 (18)	O6—P1—K	55.97 (3)
O6—K—P2ⁱⁱⁱ	174.10 (2)	O12—P1—K	61.30 (4)
O8—K—P2ⁱⁱⁱ	94.00 (2)	O5—P1—K	121.03 (3)
O3ⁱ—K—P2ⁱⁱⁱ	81.93 (2)	O10—P1—K	138.98 (4)
O7ⁱⁱ—K—P2ⁱⁱⁱ	26.858 (16)	O11—P2—O7^vi	115.17 (6)
O12—K—P2ⁱⁱⁱ	130.40 (2)	O11—P2—O1	109.17 (6)
O11ⁱⁱⁱ—K—P2ⁱⁱⁱ	26.821 (17)	O7^vi—P2—O1	114.25 (5)
O9—K—P2ⁱⁱⁱ	64.676 (17)	O11—P2—O2	109.22 (6)
O4ⁱ—K—P1	98.784 (19)	O7^vi—P2—O2	111.14 (5)
O6—K—P1	26.147 (16)	O1—P2—O2	96.24 (5)
O8—K—P1	74.92 (2)	O11—P2—K^vii	65.14 (5)
O3ⁱ—K—P1	90.78 (2)	O7^vi—P2—K^vii	62.31 (3)
O7ⁱⁱ—K—P1	150.12 (2)	O1—P2—K^vii	167.90 (4)
O12—K—P1	26.409 (16)	O2—P2—K^vii	95.76 (4)
O11ⁱⁱⁱ—K—P1	153.20 (3)	O3^viii—P3—O4	119.42 (5)
O9—K—P1	92.400 (19)	O3^viii—P3—O5	107.01 (5)
P2ⁱⁱⁱ—K—P1	156.78 (2)	O4—P3—O5	110.07 (4)
O4ⁱ—K—P4^vi	148.57 (3)	O3^viii—P3—O1^ix	109.79 (4)
O6—K—P4^vi	96.19 (2)	O4—P3—O1^ix	107.65 (5)
O8—K—P4^vi	21.809 (17)	O5—P3—O1^ix	101.41 (5)
O3ⁱ—K—P4^vi	152.95 (2)	O3^viii—P3—K^ix	90.09 (4)
O7ⁱⁱ—K—P4^vi	65.122 (18)	O5—P3—K^ix	150.30 (3)
O12—K—P4^vi	82.33 (2)	O1^ix—P3—K^ix	95.04 (4)
O11ⁱⁱⁱ—K—P4^vi	115.28 (2)	O8^v—P4—O9^vii	119.69 (6)
O9—K—P4^vi	73.308 (19)	O8^v—P4—O2	106.59 (5)
P2ⁱⁱⁱ—K—P4^vi	89.502 (11)	O9^vii—P4—O2	109.84 (5)
P1—K—P4^vi	87.099 (10)	O8^v—P4—O10	108.77 (6)
O4ⁱ—K—P3ⁱ	20.271 (16)	O9^vii—P4—O10	105.12 (6)
O6—K—P3ⁱ	58.589 (17)	O2—P4—O10	106.09 (5)
O8—K—P3ⁱ	147.16 (3)	O8^v—P4—K^v	45.22 (4)
O3ⁱ—K—P3ⁱ	68.374 (19)	O9^vii—P4—K^v	103.55 (4)
O7ⁱⁱ—K—P3ⁱ	126.64 (2)	O2—P4—K^v	145.07 (4)
O12—K—P3ⁱ	102.092 (19)	O10—P4—K^v	73.90 (4)
O11ⁱⁱⁱ—K—P3ⁱ	90.45 (2)	P2—O1—P3ⁱ	132.40 (6)
O9—K—P3ⁱ	147.36 (2)	P4—O2—P2	136.74 (6)
P2ⁱⁱⁱ—K—P3ⁱ	115.882 (11)	P3^x—O3—Pr	136.64 (5)
P1—K—P3ⁱ	81.085 (10)	P3^x—O3—K^ix	126.63 (4)
P4^vi—K—P3ⁱ	137.479 (17)	Pr—O3—K^ix	95.26 (3)
O11^iv—Pr—O9	99.75 (4)	P3—O4—Pr	139.19 (5)
O11^iv—Pr—O12	151.63 (3)	P3—O4—K^ix	119.05 (4)
O9—Pr—O12	87.04 (3)	Pr—O4—K^ix	97.10 (3)
O11^iv—Pr—O3	77.45 (4)	P1—O5—P3	132.48 (5)
O9—Pr—O3	148.45 (3)	P1—O6—Pr^vi	130.14 (5)
O12—Pr—O3	110.50 (3)	P1—O6—K	97.89 (4)
O11^iv—Pr—O4	86.26 (3)	Pr^vi—O6—K	122.05 (3)
O9—Pr—O4	143.85 (3)	P2^v—O7—Pr	136.16 (5)
O12—Pr—O4	72.87 (3)	P2^v—O7—K^xi	90.83 (4)
O3—Pr—O4	67.70 (3)	Pr—O7—K^xi	132.10 (3)
O11^iv—Pr—O6^v	137.47 (3)	P4^vi—O8—Pr	147.72 (6)
O9—Pr—O6^v	87.33 (3)	P4^vi—O8—K	112.97 (5)
O12—Pr—O6^v	69.86 (3)	Pr—O8—K	99.24 (3)
O3—Pr—O6^v	75.34 (3)	P4ⁱⁱⁱ—O9—Pr	143.02 (6)
O4—Pr—O6^v	112.14 (3)	P4ⁱⁱⁱ—O9—K	116.82 (5)
O11^iv—Pr—O7	73.45 (4)	Pr—O9—K	91.87 (3)
O9—Pr—O7	76.38 (3)	P1—O10—P4	144.49 (7)
O12—Pr—O7	134.75 (3)	P2—O11—Pr^xii	171.29 (7)
O3—Pr—O7	72.70 (3)	P2—O11—K^vii	88.04 (5)
O4—Pr—O7	138.54 (3)	Pr^xii—O11—K^vii	94.52 (4)
O6^v—Pr—O7	67.60 (3)	P1—O12—Pr	144.39 (5)
O11^iv—Pr—O8	80.66 (4)	P1—O12—K	92.29 (5)
O9—Pr—O8	71.69 (3)	Pr—O12—K	98.06 (3)

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

Experimental details

Crystal data
Chemical formula	KPr(PO3)₄
M_r	495.89
Crystal system, space group	Monoclinic, P2₁
Temperature (K)	296
a, b, c (Å)	7.2872 (2), 8.4570 (3), 8.0268 (2)
β (°)	91.994 (1)
V (Å³)	494.37 (3)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	6.06
Crystal size (mm)	0.29 × 0.21 × 0.16

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2008)
T_min, T_max	0.448, 0.751
No. of measured, independent and observed [I > 2σ(I)] reflections	45940, 13443, 13257
R_int	0.034
(sin θ/λ)_max (Å⁻¹)	1.186

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.018, 0.043, 1.07
No. of reflections	13443
No. of parameters	164
No. of restraints	1
Δρ_max, Δρ_min (e Å⁻³)	2.86, −2.42
Absolute structure	Flack (1983), 6278 Friedel pairs
Absolute structure parameter	0.022 (3)

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), CaRine (Boudias & Monceau, 1998) and ORTEP-3 for Windows (Farrugia, 1997), SHELXTL (Sheldrick, 2008).

Selected bond lengths (Å) top

P1—O6	1.4841 (8)	P3—O3ⁱⁱ	1.4806 (8)
P1—O12	1.4850 (8)	P3—O4	1.4832 (8)
P1—O5	1.5881 (7)	P3—O5	1.5902 (8)
P1—O10	1.5887 (9)	P3—O1ⁱⁱⁱ	1.5980 (8)
P2—O11	1.4810 (9)	P4—O8^iv	1.4777 (8)
P2—O7ⁱ	1.4822 (8)	P4—O9^v	1.4829 (8)
P2—O1	1.5926 (8)	P4—O2	1.5874 (8)
P2—O2	1.5941 (8)	P4—O10	1.5973 (9)

Symmetry codes: (i) −x+1, y+1/2, −z+1; (ii) −x, y+1/2, −z+1; (iii) x−1, y, z; (iv) −x+1, y−1/2, −z+1; (v) x, y, z−1.

References

Boudias, C. & Monceau, D. (1998). CaRine. CaRine Crystallography, DIVERGENT SA, Compiègne, France. Google Scholar
Bruker (2008). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Durif, A. (1995). Crystal Chemistry of Condensed Phosphates. New York and London: Plenum Press. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Hong, H. Y. (1975). Mater. Res. Bull. 10, 1105–1110. CrossRef CAS Web of Science Google Scholar
Horchani-Naifer, K., Jouini, A. & Férid, M. (2008). Acta Cryst. E64, i34. Web of Science CrossRef IUCr Journals Google Scholar
Jaoudi, K., Naïli, H., Zouari, N., Mhiri, T. & Daoud, A. (2003). J. Alloys Compd, 354, 104–114. Google Scholar
Krutik, V.M, Pushcharovskii, D. Yu., Pobedimskaya, E.A. & Belov N.V. (1980). Dokl. Akad. Nauk SSSR, 252, 607–610. CAS Google Scholar
Lin, Y. H., Hu, N. H., Zhou, Q. L. & Liu, S. Z. (1983). Wu Li Hsueh Pao, 32, 675–680. CAS Google Scholar
Ninghai, H., Yonghua, L., Zhou, Q. L. & Liu, S. Z. (1984). Yingyong Huaxue, 1, 47–50. Google Scholar
Palkina, K. K., Maksimova, S. I., Chudinova, N. N., Vinogradova, N. V. & Chibiskova, N. T. (1981). Izv. Akad. Nauk. SSSR Neorg. Mater. 17, 110–115. CAS Google Scholar
Parreu, I., Carvajal, J. J., Solans, X., Diaz, F. & Aguilo, M. (2006). Chem. Mater. 18, 221–228. Web of Science CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Xing, Y., Hu, N. H., Zhou, Q. L., Hong, G. Y. & Yue, S. Y. (1987). Wuli Huaxue Xenbao, 3, 218–221. CAS Google Scholar
Zhou, Q.-L., Hu, N.-H., Hong, G.-Y. & Yue, S.-Y. (1987). Yingyong Huaxue, 4, 46–50. CAS Google Scholar
Zhu, J., Cheng, W., Zhang, H. & Wang, Y. (2009). J. Lumin. 129, 1326–1331. Web of Science CrossRef CAS Google Scholar