Sodium samarium tetra­kis­(poly­phosphate), NaSm(PO₃)₄

NaSm(PO₃)₄ has been prepared by solid state reactions. It belongs to type II of the structural family of M^ILn^III(PO₃)₄ compounds (M^I = alkali metal and Ln^III = rare earth metal) and is composed of _∞(PO₃)_n]ⁿ⁻ polyphosphate chains with a repeating unit of four PO₄ tetra­hedra. The chains extend parallel to [100] and share O atoms with irregular SmO₈ polyhedra, forming a three-dimensional framework which delimits tunnels occupied by Na⁺ cations in a distorted octa­hedral environment.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](P-O) = 0.004 Å
• R factor = 0.037
• wR factor = 0.068
• Data-to-parameter ratio = 13.0

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT923_ALERT_1_A S    values in the CIF and FCF Differ by .......       0.10

Author Response: this might be caused by a different weighting scheme used by SHELXL and PLATON

 _vrf_PLAT922_I
 PROBLEM
 PLAT922 Type_1 Test for wR2 Consistency between CIF & FCF(Reported)
 RESPONSE: this might be caused by a different weighting scheme used by SHELXL
  this might be caused by a different weighting scheme used by SHELXL
 and PLATON

 _vrf_PLAT927_I
 PROBLEM
 PLAT922 Type_1 Test for wR2 Consistency between CIF & FCF(Reported)
 RESPONSE: this might be caused by a different weighting scheme used by SHELXL
  this might be caused by a different weighting scheme used by SHELXL
 and PLATON


Alert level B
PLAT922_ALERT_1_B wR2 * 100.0 in the CIF and FCF Differ by .......      -3.26

Author Response: _vrf_PLAT923_I

PLAT927_ALERT_1_B Reported and Calculated  wR2 * 100.0 Differ by .      -3.26

Author Response: _vrf_PLAT923_I

Alert level C
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.96
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       2.20 eA-3
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600         12

Alert level G
PLAT128_ALERT_4_G Alternate Setting of Space-group P21/c   .......      P21/n
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported   _diffrn_ambient_temperature        293 K

   1 ALERT level A = In general: serious problem
   2 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   3 ALERT level G = General alerts; check

   5 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

In recent years, alkali rare earth polyphosphates with general formula M^ILn^III(PO₃)₄ (M^I = alkali metal, Ln^III = rare earth metal) have been studied mainly due to their rich structural chemistry and interesting physical and chemical properties, such as high luminescence efficiency (Durif, 1995). The nomenclature of M^ILn^III(PO₃)₄ compounds has been proposed by Palkina et al. (1981) and is generally accepted today. Many compounds of this family have been reported, for example, LiLn(PO₃)₄ (Ln =Y, Sm, Dy) (Zhao et al., 2008, 2010), KGdP₄O₁₂ (Ettis et al., 2003), KNd(PO₃)₄ (Parreu et al., 2007) and CsEu(PO₃)₄ (Zhu et al., 2009). For the compound NaSm(PO₃)₄ only unit-cell parameters have been reported on basis of refined X-ray powder diffraction data (Ferid et al., 1984).

The structure of NaSm(PO₃)₄ is characterized by a three-dimensional framework built up of irregular SmO₈ polyhedra linked with polyphosphate chains via Sm–O–P bridges, as show in Fig. 2. The undulated [(PO₃)_n]^n- chains have a repeating unit of four corner-sharing PO₄ tetrahedra and extend parallel to the a-axis. Furthermore, the framework delimits tunnels in which the Na⁺ ions are located. They are 6-coordinated by O atoms with Na—O distances ranging from 2.386 (5)—2.741 (5) Å in a distorted octahedral arrangement.

Related literature

The unit cell of NaSm(PO₃)₄, derived from X-ray powder data, was reported by Ferid et al. (1984). For classification of M^ILn^III(PO₃)₄ structures, see: Palkina et al. (1981); Durif (1995). Structures, properties and applications of other members of this family were discussed by Ettis et al. (2003); Parreu et al. (2007); Zhao et al. (2008, 2010); Zhu et al. (2009).

S2. Experimental

The finely ground reagents Na₂CO₃, Sm₂O₃, and NH₄H₂PO₄ were mixed in a molar ratio of Na: Sm: P = 7: 1: 10, placed in a Pt crucible, and heated at 673 K for 4 h. The mixture was re-ground and heated at 1173 K for 20 h, then cooled to 673 K at a rate of 4 K h^-1, and finally quenched to room temperature. A few yellow crystals of the title compound with prismatic shape were obtained.

S3. Refinement

The highest peak in the difference electron density map is located 1.49 Å from atom Sm1 while the deepest hole is 1.98 Å from atom O8.

Computing details

Data collection: CrystalClear (Rigaku, 2004); cell refinement: CrystalClear (Rigaku, 2004); data reduction: CrystalClear (Rigaku, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008) and PLATON (Spek, 2009); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2004); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. Asymmetric unit of the structure of NaSm(PO3)4 with the atom labelling scheme. The displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. View of the crystal structure of NaSm(PO3)4 in a projection down [010].

Sodium samarium tetrakis(polyphosphate)

Crystal data

NaSm(PO3)4	F(000) = 916
Mr = 489.22	Dx = 3.504 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2180 reflections
a = 7.1924 (13) Å	θ = 2.1–27.5°
b = 13.091 (2) Å	µ = 7.14 mm^−1
c = 9.8480 (17) Å	T = 293 K
β = 90.396 (10)°	Prism, yellow
V = 927.2 (3) Å^3	0.20 × 0.02 × 0.02 mm
Z = 4

Data collection

Rigaku Mercury70 CCD diffractometer	2111 independent reflections
Radiation source: fine-focus sealed tube	1868 reflections with I > 2σ(I)
Rigaku Graphite Monochromator DIFFRACTOMETER TYPE monochromator	Rint = 0.041
Detector resolution: 14.6306 pixels mm^-1	θmax = 27.5°, θmin = 2.6°
ω scans	h = −9→9
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	k = −15→17
Tmin = 0.329, Tmax = 0.870	l = −12→12
7036 measured reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F^2 > 2σ(F^2)] = 0.037	Secondary atom site location: difference Fourier map
wR(F^2) = 0.068	w = 1/[σ^2(Fo^2) + (0.0639P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.15	(Δ/σ)max < 0.001
2111 reflections	Δρmax = 2.38 e Å^−3
163 parameters	Δρmin = −0.80 e Å^−3

Special details

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 F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > σ(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ 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
Na1	−0.0002 (4)	0.7220 (2)	0.5648 (3)	0.0210 (6)
Sm1	0.51300 (4)	0.71807 (2)	0.47634 (3)	0.00716 (10)
P1	0.2493 (2)	0.60065 (11)	0.74392 (15)	0.0064 (3)
P2	0.8781 (2)	0.61480 (12)	0.26404 (15)	0.0063 (3)
P3	0.2690 (2)	0.59026 (12)	0.19783 (15)	0.0065 (3)
P4	0.6463 (2)	0.62775 (12)	0.80511 (15)	0.0065 (3)
O1	0.2374 (6)	0.6610 (3)	0.0824 (4)	0.0117 (9)
O2	0.7180 (5)	0.7105 (3)	0.8947 (4)	0.0099 (9)
O3	0.2829 (6)	0.4784 (3)	0.1343 (4)	0.0091 (9)
O4	0.8029 (6)	0.6454 (3)	0.3976 (4)	0.0095 (9)
O5	0.0936 (6)	0.6652 (3)	0.7951 (4)	0.0103 (9)
O6	0.0886 (6)	0.5804 (3)	0.2895 (4)	0.0105 (9)
O7	0.2159 (6)	0.4860 (3)	0.7898 (4)	0.0098 (9)
O8	0.6799 (6)	0.6328 (3)	0.6572 (4)	0.0100 (9)
O9	0.8672 (6)	0.6896 (3)	0.1519 (4)	0.0105 (9)
O10	0.2860 (6)	0.6073 (3)	0.5963 (4)	0.0102 (9)
O11	0.4284 (6)	0.6243 (3)	0.8331 (4)	0.0082 (9)
O12	0.4293 (6)	0.6102 (3)	0.2901 (4)	0.0135 (9)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Na1	0.0172 (14)	0.0309 (16)	0.0149 (12)	0.0063 (13)	−0.0028 (11)	0.0029 (12)
Sm1	0.00640 (16)	0.00857 (15)	0.00651 (15)	−0.00002 (13)	0.00033 (11)	−0.00033 (13)
P1	0.0049 (7)	0.0065 (7)	0.0078 (7)	−0.0001 (6)	−0.0001 (6)	−0.0006 (6)
P2	0.0055 (7)	0.0053 (7)	0.0082 (7)	0.0002 (6)	0.0012 (6)	0.0002 (6)
P3	0.0046 (7)	0.0064 (7)	0.0084 (7)	0.0013 (6)	0.0000 (6)	−0.0001 (6)
P4	0.0053 (7)	0.0059 (7)	0.0084 (7)	−0.0007 (6)	0.0001 (6)	−0.0007 (6)
O1	0.010 (2)	0.013 (2)	0.012 (2)	0.0027 (18)	0.0012 (18)	0.0029 (18)
O2	0.005 (2)	0.009 (2)	0.016 (2)	−0.0013 (17)	−0.0032 (17)	−0.0044 (18)
O3	0.014 (2)	0.005 (2)	0.009 (2)	0.0016 (17)	−0.0019 (17)	−0.0014 (17)
O4	0.007 (2)	0.012 (2)	0.009 (2)	0.0009 (17)	0.0012 (17)	−0.0007 (17)
O5	0.005 (2)	0.013 (2)	0.013 (2)	0.0014 (17)	0.0020 (17)	−0.0007 (18)
O6	0.008 (2)	0.015 (2)	0.008 (2)	−0.0019 (18)	0.0034 (17)	0.0022 (18)
O7	0.014 (2)	0.005 (2)	0.011 (2)	−0.0042 (17)	−0.0001 (18)	−0.0013 (16)
O8	0.010 (2)	0.013 (2)	0.0064 (19)	0.0015 (18)	0.0028 (17)	0.0026 (17)
O9	0.011 (2)	0.008 (2)	0.012 (2)	0.0023 (17)	0.0018 (18)	0.0028 (17)
O10	0.012 (2)	0.010 (2)	0.009 (2)	−0.0015 (18)	0.0019 (18)	−0.0004 (17)
O11	0.007 (2)	0.010 (2)	0.0076 (19)	−0.0012 (17)	−0.0028 (17)	−0.0021 (16)
O12	0.008 (2)	0.015 (2)	0.017 (2)	−0.0020 (18)	−0.0044 (18)	−0.0047 (18)

Geometric parameters (Å, º)

Na1—O4^i	2.386 (5)	P2—O6^vii	1.598 (4)
Na1—O1^ii	2.438 (5)	P3—O1	1.482 (4)
Na1—O2^iii	2.468 (5)	P3—O12	1.486 (4)
Na1—O5	2.475 (5)	P3—O6	1.591 (4)
Na1—O10	2.565 (5)	P3—O3	1.596 (4)
Na1—O8^i	2.741 (5)	P4—O8	1.479 (4)
Na1—O9^ii	3.005 (5)	P4—O2	1.487 (4)
Sm1—O9^ii	2.362 (4)	P4—O11	1.594 (4)
Sm1—O12	2.389 (4)	P4—O3^vi	1.595 (4)
Sm1—O8	2.415 (4)	O1—Na1^iv	2.438 (5)
Sm1—O5^iv	2.423 (4)	O1—Sm1^iii	2.486 (4)
Sm1—O4	2.424 (4)	O2—Sm1^v	2.449 (4)
Sm1—O2^iii	2.449 (4)	O2—Na1^v	2.468 (5)
Sm1—O1^v	2.486 (4)	O3—P4^vi	1.595 (4)
Sm1—O10	2.488 (4)	O4—Na1^vii	2.386 (5)
P1—O10	1.482 (4)	O5—Sm1^ii	2.423 (4)
P1—O5	1.494 (4)	O6—P2^i	1.598 (4)
P1—O11	1.584 (4)	O7—P2^vi	1.574 (4)
P1—O7	1.586 (4)	O8—Na1^vii	2.741 (5)
P2—O9	1.477 (4)	O9—Sm1^iv	2.362 (4)
P2—O4	1.481 (4)	O9—Na1^iv	3.005 (5)
P2—O7^vi	1.574 (4)
O4^i—Na1—O1^ii	81.77 (16)	O10—P1—O5	115.9 (2)
O4^i—Na1—O2^iii	93.40 (16)	O10—P1—O11	112.5 (2)
O1^ii—Na1—O2^iii	108.62 (17)	O5—P1—O11	108.1 (2)
O4^i—Na1—O5	131.55 (19)	O10—P1—O7	111.3 (2)
O1^ii—Na1—O5	109.24 (16)	O5—P1—O7	108.9 (2)
O2^iii—Na1—O5	123.97 (17)	O11—P1—O7	98.7 (2)
O4^i—Na1—O10	108.05 (17)	O9—P2—O4	117.8 (2)
O1^ii—Na1—O10	168.60 (18)	O9—P2—O7^vi	106.5 (2)
O2^iii—Na1—O10	77.17 (15)	O4—P2—O7^vi	111.6 (2)
O5—Na1—O10	60.02 (14)	O9—P2—O6^vii	110.5 (2)
O4^i—Na1—O8^i	63.56 (14)	O4—P2—O6^vii	106.8 (2)
O1^ii—Na1—O8^i	65.92 (15)	O7^vi—P2—O6^vii	102.8 (2)
O2^iii—Na1—O8^i	156.55 (17)	O1—P3—O12	118.2 (3)
O5—Na1—O8^i	78.01 (15)	O1—P3—O6	111.4 (2)
O10—Na1—O8^i	112.69 (17)	O12—P3—O6	107.4 (2)
O4^i—Na1—O9^ii	151.14 (16)	O1—P3—O3	106.4 (2)
O1^ii—Na1—O9^ii	114.66 (17)	O12—P3—O3	110.5 (2)
O2^iii—Na1—O9^ii	59.56 (14)	O6—P3—O3	101.6 (2)
O5—Na1—O9^ii	67.70 (14)	O8—P4—O2	119.5 (3)
O10—Na1—O9^ii	59.17 (13)	O8—P4—O11	109.8 (2)
O8^i—Na1—O9^ii	143.89 (15)	O2—P4—O11	104.8 (2)
P1—Na1—O9^ii	60.64 (10)	O8—P4—O3^vi	110.7 (2)
O9^ii—Sm1—O12	138.95 (15)	O2—P4—O3^vi	107.7 (2)
O9^ii—Sm1—O8	85.27 (14)	O11—P4—O3^vi	102.9 (2)
O12—Sm1—O8	114.50 (15)	P3—O1—Sm1^iii	144.7 (2)
O9^ii—Sm1—O5^iv	109.05 (14)	Na1^iv—O1—Sm1^iii	94.05 (16)
O12—Sm1—O5^iv	82.37 (15)	P4—O2—Sm1^v	140.3 (2)
O8—Sm1—O5^iv	135.61 (14)	P4—O2—Na1^v	116.4 (2)
O9^ii—Sm1—O4	145.34 (14)	Sm1^v—O2—Na1^v	101.18 (16)
O12—Sm1—O4	74.63 (14)	P4^vi—O3—P3	132.3 (3)
O8—Sm1—O4	68.31 (13)	P2—O4—Na1^vii	120.5 (2)
O5^iv—Sm1—O4	78.51 (14)	P2—O4—Sm1	135.3 (2)
O9^ii—Sm1—O2^iii	69.92 (14)	Na1^vii—O4—Sm1	97.01 (16)
O12—Sm1—O2^iii	76.16 (14)	P1—O5—Sm1^ii	142.1 (2)
O8—Sm1—O2^iii	147.54 (13)	P1—O5—Na1	93.5 (2)
O5^iv—Sm1—O2^iii	74.25 (14)	Sm1^ii—O5—Na1	114.88 (18)
O4—Sm1—O2^iii	142.17 (13)	P3—O6—P2^i	131.6 (3)
O9^ii—Sm1—O1^v	69.91 (14)	P2^vi—O7—P1	139.8 (3)
O12—Sm1—O1^v	149.17 (14)	P4—O8—Sm1	131.5 (2)
O8—Sm1—O1^v	70.50 (14)	P4—O8—Na1^vii	119.3 (2)
O5^iv—Sm1—O1^v	75.54 (14)	Sm1—O8—Na1^vii	88.43 (14)
O4—Sm1—O1^v	80.05 (14)	P2—O9—Sm1^iv	149.9 (3)
O2^iii—Sm1—O1^v	116.94 (14)	P2—O9—Na1^iv	120.7 (2)
O9^ii—Sm1—O10	69.79 (14)	Sm1^iv—O9—Na1^iv	89.30 (14)
O12—Sm1—O10	81.81 (14)	P1—O10—Sm1	128.5 (2)
O8—Sm1—O10	72.84 (14)	P1—O10—Na1	90.3 (2)
O5^iv—Sm1—O10	151.45 (14)	Sm1—O10—Na1	97.49 (15)
O4—Sm1—O10	119.46 (14)	P1—O11—P4	135.0 (3)
O2^iii—Sm1—O10	78.97 (14)	P3—O12—Sm1	139.8 (3)
O1^v—Sm1—O10	126.71 (13)

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