NASICON-type Na₃V₂(PO₄)₃

Single crystals of the title compound, tris­odium divanadium(III) tris­(orthophosphate), were grown from a self-flux in the system Na₄P₂O₇-NaVP₂O₇. Na₃V₂(PO₄)₃ belongs to the family of NASICON-related structures and is built up from isolated [VO₆] octa­hedra (3. symmetry) and [PO₄] tetra­hedra (.2 symmetry) inter­linked via corners to establish the framework anion [V₂(PO₄)₃]^3-. The two independent Na⁺ cations are partially occupied [site-occupancy factors = 0.805 (18) and 0.731 (7)] and are located in channels with two different oxygen environments, viz sixfold coordination for the first (. symmetry) and eightfold for the second (.2 symmetry) Na⁺ cation.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](P-O) = 0.001 Å
• Disorder in solvent or counterion
• R factor = 0.032
• wR factor = 0.075
• Data-to-parameter ratio = 36.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT214_ALERT_2_C Atom Na1     (Anion/Solvent) ADP max/min Ratio         4.40 oblat
PLAT041_ALERT_1_C Calc. and Reported SumFormula    Strings  Differ          ?
PLAT042_ALERT_1_C Calc. and Reported MoietyFormula Strings  Differ          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       0.33 Ratio

Alert level G
PLAT083_ALERT_2_G SHELXL Second Parameter in WGHT Unusually Large.       5.14
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported   _diffrn_ambient_temperature        293 K
PLAT302_ALERT_4_G Note: Anion/Solvent Disorder ...................      77.00 Perc.
PLAT811_ALERT_5_G No ADDSYM Analysis: Too Many Excluded Atoms ....          !

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   5 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
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

The structures and properties of complex phosphates with general formula Na₃M^III₂(PO₄)₃ (M^III - Sc, Fe, Cr) have been intensively investigated, for instance: (Collin et al., 1986; Genkina et al., 1991; Lazoryak et al., 1980; Lucazeau et al., 1986; Masquelier et al., 1992; Susman et al., 1983). The structure of NASICON-type Na₃V₂(PO₄)₃, (I), is reported here.

In the asymmetric unit of (I) (Fig. 1) there is one V and one P atom, while other,atoms (Na and O) are represented in two distinct positions each. The main building block of (I) (Fig. 2) involves two VO₆ octahedra interlinked by three phosphate groups lying along the c axis. As a result of the block aggregation, a three-dimensional framework with an overall composition of [V₂(PO₄)₃]^3- is organized (Fig. 3).

Sodium atoms are located in the voids of the framework with six- (position 6b) and eightfold (18b) coordination when a cut-off distance of 2.9 Å is considered.

Related literature

For structures and properties of complex phosphates with general formula Na₃M^III₂(PO₄)₃ (M^III = Sc, Fe, Cr), see: Collin et al. (1986); Genkina et al. (1991); Lazoryak et al. (1980); Lucazeau et al. (1986); Masquelier et al. (1992); Susman et al. (1983). For preparation of NaVP₂O₇ which was used as an educt for crystal growth of the title compound, see: Zatovsky et al. (1999).

S2. Experimental

Crystals of (I) were obtained in the system Na₄P₂O₇—NaVP₂O₇ using a high-temperature crystallization technique. Initial NaVP₂O₇ was prepared in accordance to Zatovsky et al. (1999). A thoroughly ground mixture of Na₄P₂O₇ and NaVP₂O₇ (ratio 1:3) was heated up to 1343 K and then kept for 2 h in a sealed silica tube under vacuum. Then it was cooled down to 823 K with a rate of 5 K/h and left in the furnace to reach room temperature. The final product, green prismatic crystals, was leached out from the solidified melt with boiling water.

S3. Refinement

After refinement of a basic model and an accurate definition of the atom positions, the occupancy of Na1 and Na2 sites were refined freely and were finally restrained to meet the criterion for charge balance. The highest peak and the deepest hole in the final difference map is located at 0.00 Šfrom Na1 (1.12 e/ų) and 0.60 from Na2 (-0.74 e/ų) respectively.

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis CCD (Oxford Diffraction, 2006); data reduction: CrysAlis RED (Oxford Diffraction, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Farrugia, 1999) and enCIFer (Allen et al., 2004).

Figures

	Fig. 1. The asymmetric unit of Na3V2(PO4)3 with displacement ellipsoids at the 50% probability level.
	Fig. 2. The central building block [V2(PO4)3] in the structure of compound (I).
	Fig. 3. The view of the structure of compound (I) on the ab plane.

trisodium divanadium(III) tris(orthophosphate)

Crystal data

Na3V2(PO4)3	Dx = 3.156 Mg m^−3
Mr = 455.76	Mo Kα radiation, λ = 0.71073 Å
Trigonal, R3c	Cell parameters from 12580 reflections
Hall symbol: -R 3 2"c	θ = 3.3–45.0°
a = 8.7288 (2) Å	µ = 2.66 mm^−1
c = 21.8042 (7) Å	T = 293 K
V = 1438.73 (7) Å^3	Prism, green
Z = 6	0.20 × 0.15 × 0.10 mm
F(000) = 1320

Data collection

Oxford Diffraction Xcalibur-3 CCD diffractometer	1331 independent reflections
Radiation source: fine-focus sealed tube	1153 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.063
φ and ω scans	θmax = 45°, θmin = 3.3°
Absorption correction: multi-scan (Blessing, 1995)	h = −17→16
Tmin = 0.635, Tmax = 0.780	k = −17→17
12580 measured reflections	l = −43→41

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.032	w = 1/[σ^2(Fo^2) + (0.0264P)^2 + 5.1429P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.075	(Δ/σ)max < 0.001
S = 1.1	Δρmax = 1.12 e Å^−3
1331 reflections	Δρmin = −0.74 e Å^−3
37 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008)
0 restraints	Extinction coefficient: 0.0056 (4)

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 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	Occ. (<1)
V1	0.3333	0.6667	0.019498 (13)	0.00690 (6)
Na1	0.3333	0.6667	0.1667	0.149 (5)	0.805 (18)
Na2	0.6667	0.96726 (19)	0.0833	0.0522 (10)	0.731 (7)
P1	−0.04273 (5)	0.3333	0.0833	0.00866 (8)
O1	0.14193 (13)	0.49765 (14)	0.07762 (5)	0.01643 (16)
O2	0.54047 (16)	0.84480 (17)	−0.02643 (7)	0.0259 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
V1	0.00643 (7)	0.00643 (7)	0.00784 (10)	0.00321 (4)	0	0
Na1	0.218 (8)	0.218 (8)	0.0111 (14)	0.109 (4)	0	0
Na2	0.0224 (8)	0.0170 (5)	0.119 (2)	0.0112 (4)	−0.0354 (11)	−0.0177 (5)
P1	0.00635 (10)	0.00714 (14)	0.01276 (15)	0.00357 (7)	0.00152 (5)	0.00305 (11)
O1	0.0089 (3)	0.0130 (3)	0.0220 (4)	0.0015 (3)	0.0048 (3)	0.0057 (3)
O2	0.0185 (4)	0.0223 (5)	0.0322 (6)	0.0067 (4)	0.0143 (4)	0.0151 (4)

Geometric parameters (Å, º)

V1—O2^i	1.9693 (10)	Na2—O1^ii	2.3883 (12)
V1—O2	1.9693 (11)	Na2—O1^vi	2.3883 (12)
V1—O2^ii	1.9693 (10)	Na2—O1^i	2.4448 (19)
V1—O1^ii	2.0271 (9)	Na2—O1^vii	2.4449 (19)
V1—O1	2.0271 (9)	Na2—O2^viii	2.6280 (16)
V1—O1^i	2.0271 (9)	Na2—O2	2.6281 (16)
V1—Na2^i	3.1070 (6)	Na2—O2^ix	2.8352 (19)
V1—Na2	3.1070 (7)	Na2—O2^x	2.8352 (19)
V1—Na2^ii	3.1070 (6)	Na2—P1^xi	2.9222 (11)
V1—Na1	3.2096 (3)	Na2—P1^ii	2.9222 (11)
Na1—O1	2.5045 (11)	Na2—P1^i	2.9968 (17)
Na1—O1^ii	2.5045 (11)	P1—O2^xii	1.5227 (12)
Na1—O1^i	2.5045 (11)	P1—O2^xiii	1.5227 (12)
Na1—O1^iii	2.5045 (11)	P1—O1	1.5358 (10)
Na1—O1^iv	2.5045 (11)	P1—O1^xiv	1.5359 (10)
Na1—O1^v	2.5046 (11)	P1—Na2^xv	2.9222 (11)
Na1—V1^iv	3.2081 (2)	P1—Na2^i	2.9222 (11)
Na1—Na2^i	3.3193 (6)	P1—Na2^ii	2.9968 (17)
Na1—Na2^v	3.3193 (6)	O1—Na2^i	2.3883 (12)
Na1—Na2	3.3193 (6)	O1—Na2^ii	2.4448 (19)
Na1—Na2^ii	3.3205 (6)
O2^i—V1—O2	96.44 (6)	O1^ii—Na2—O2	68.20 (4)
O2^i—V1—O2^ii	96.44 (6)	O1^vi—Na2—O2	115.98 (4)
O2—V1—O2^ii	96.44 (6)	O1^i—Na2—O2	66.40 (4)
O2^i—V1—O1^ii	88.22 (5)	O1^vii—Na2—O2	93.51 (6)
O2—V1—O1^ii	89.72 (5)	O2^viii—Na2—O2	157.25 (9)
O2^ii—V1—O1^ii	171.80 (6)	O1^ii—Na2—O2^ix	54.99 (4)
O2^i—V1—O1	89.72 (5)	O1^vi—Na2—O2^ix	108.39 (6)
O2—V1—O1	171.80 (6)	O1^i—Na2—O2^ix	115.94 (4)
O2^ii—V1—O1	88.22 (5)	O1^vii—Na2—O2^ix	151.11 (4)
O1^ii—V1—O1	85.05 (5)	O2^viii—Na2—O2^ix	85.67 (3)
O2^i—V1—O1^i	171.80 (6)	O2—Na2—O2^ix	112.13 (5)
O2—V1—O1^i	88.22 (5)	O1^ii—Na2—O2^x	108.39 (6)
O2^ii—V1—O1^i	89.72 (5)	O1^vi—Na2—O2^x	54.99 (4)
O1^ii—V1—O1^i	85.05 (5)	O1^i—Na2—O2^x	151.10 (4)
O1—V1—O1^i	85.05 (5)	O1^vii—Na2—O2^x	115.94 (4)
O1—Na1—O1^ii	66.33 (3)	O2^viii—Na2—O2^x	112.13 (5)
O1—Na1—O1^i	66.33 (3)	O2—Na2—O2^x	85.67 (3)
O1^ii—Na1—O1^i	66.33 (3)	O2^ix—Na2—O2^x	80.45 (7)
O1—Na1—O1^iii	113.67 (3)	O2^xii—P1—O2^xiii	111.67 (12)
O1^ii—Na1—O1^iii	180	O2^xii—P1—O1	106.07 (7)
O1^i—Na1—O1^iii	113.67 (3)	O2^xiii—P1—O1	112.18 (7)
O1—Na1—O1^iv	180	O2^xii—P1—O1^xiv	112.19 (7)
O1^ii—Na1—O1^iv	113.67 (3)	O2^xiii—P1—O1^xiv	106.07 (7)
O1^i—Na1—O1^iv	113.67 (3)	O1—P1—O1^xiv	108.74 (9)
O1^iii—Na1—O1^iv	66.33 (3)	P1—O1—V1	145.95 (7)
O1—Na1—O1^v	113.67 (3)	P1—O1—Na2^i	93.73 (6)
O1^ii—Na1—O1^v	113.67 (3)	V1—O1—Na2^i	89.05 (5)
O1^i—Na1—O1^v	180	P1—O1—Na2^ii	94.93 (5)
O1^iii—Na1—O1^v	66.33 (3)	V1—O1—Na2^ii	87.50 (4)
O1^iv—Na1—O1^v	66.33 (3)	Na2^i—O1—Na2^ii	169.09 (5)
O1^ii—Na2—O1^vi	160.52 (9)	P1—O1—Na1	124.53 (6)
O1^ii—Na2—O1^i	69.07 (5)	V1—O1—Na1	89.52 (4)
O1^vi—Na2—O1^i	130.40 (6)	Na2^i—O1—Na1	85.40 (5)
O1^ii—Na2—O1^vii	130.40 (6)	Na2^ii—O1—Na1	84.23 (4)
O1^vi—Na2—O1^vii	69.07 (5)	P1^xvi—O2—V1	151.38 (10)
O1^i—Na2—O1^vii	61.41 (6)	P1^xvi—O2—Na2	120.77 (8)
O1^ii—Na2—O2^viii	115.98 (4)	V1—O2—Na2	83.72 (5)
O1^vi—Na2—O2^viii	68.20 (4)	P1^xvi—O2—Na2^xvii	77.85 (5)
O1^i—Na2—O2^viii	93.51 (6)	V1—O2—Na2^xvii	107.30 (6)
O1^vii—Na2—O2^viii	66.40 (4)	Na2—O2—Na2^xvii	113.64 (7)

Symmetry codes: (i) −y+1, x−y+1, z; (ii) −x+y, −x+1, z; (iii) x−y+2/3, x+1/3, −z+1/3; (iv) −x+2/3, −y+4/3, −z+1/3; (v) y−1/3, −x+y+1/3, −z+1/3; (vi) x−y+4/3, −y+5/3, −z+1/6; (vii) y+1/3, x+2/3, −z+1/6; (viii) −x+4/3, −x+y+2/3, −z+1/6; (ix) −y+4/3, −x+5/3, z+1/6; (x) y, −x+y+1, −z; (xi) x+1, y+1, z; (xii) x−2/3, x−y+2/3, z+1/6; (xiii) y−1, −x+y, −z; (xiv) x−y+1/3, −y+2/3, −z+1/6; (xv) x−1, y−1, z; (xvi) x−y+1, x+1, −z; (xvii) x−y+1, x, −z.