An ortho­rhom­bic polymorph of the ultraphosphate YP₅O₁₄

Single crystals of yttrium penta­phosphate(V), YP₅O₁₄, were obtained by solid-state reaction. The ortho­rhom­bic title compound belongs to the family of ultraphosphates and is the second polymorph of this composition. It is isotypic with its Ho and Er analogues. The structure contains two bridging Q²-type PO₄ tetra­hedra and one branching Q³-type PO₄ tetra­hedron, leading to infinite ultraphosphate ribbons running along the a axis. The coordination polyhedron around the Y³⁺ cation may be described as distorted bicapped trigonal-prismatic. The YO₈ polyhedra are isolated from each other. They are linked by corner-sharing to the O atoms of six Q²-type and of two Q³-type PO₄ tetra­hedra into a three-dimensional framework.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](P-O) = 0.004 Å
• R factor = 0.030
• wR factor = 0.110
• Data-to-parameter ratio = 12.3

checkCIF/PLATON results

No syntax errors found



Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR) is > 1.10
            Tmin and Tmax reported:      0.330     0.460
            Tmin and Tmax expected:      0.300     0.474
            RR =      1.134
            Please check that your absorption correction is appropriate.
            Value of measurement temperature given =   296.000
            Value of melting point given =     0.000
PLAT083_ALERT_2_C SHELXL Second Parameter in WGHT unusually Large.       6.00
PLAT395_ALERT_2_C Deviating  X-O-Y  Angle from 120 Deg for      O5     140.40 Deg.
PLAT060_ALERT_4_C Ratio Tmax/Tmin (Exp-to-Rep) (too) Large .......       1.14
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       1.03

Alert level G
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

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

   1 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
   1 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

---

S1. Comment

Rare earths ultraphosphates exhibit a growing attention because of their potential applications as optical materials, including lasers, phosphors, matrices for the energy up-conversion and more recently for plasma display panels (PDP) as they exhibit an absorption band overlapping the emission spectrum of a Xe—Ne plasma in the VUV region (Rao & Devine, 2000; Moine & Bizarri, 2006). The non-optically active matrix of YP₅O₁₄ can be used as host material for such applications and hence needs to be structurally well-characterized. This article deals with the crystal structure refinement of the orthorhombic polymorph that is isotypic with HoP₅O₁₄ (Durif, 1972) and ErP₅O₁₄ (Katrusiak & Kaczmarek, 1995; Dimitrova et al. 2004).

Two PO₄ tetrahedra are Q² type bridging tetrahedra with typical two shorter and two longer P—O bonds (Durif, 1995). The third PO₄ tetrahedron is a branching Q³ type tetrahedron and exhibits also characteristic bond lengths ranging from 1.455 (4) to 1.567 (3) Å. These PO₄ groups form infinite ribbons with composition (P₅O₁₄)^3- which can be considered as built of two infinite (PO₃)_n chains running along the a axis and connected by alternating up and down capping PO₄ tetrahedra (Figs. 1, 2). The repetition unit in these ribbons is P₁₀O₂₈.

The coordination polyhedron around the Y³⁺ cation is a distorted bicapped trigonal prism according to criteria defined by Porai-Koshits & Aslanov (1972) with (δ₁ = 0°, δ₂ = 18.28°, δ₃ = δ₄ = 42.87°; theoretical values δ₁ = 0°, δ₂ = 21.7°, δ₃ = δ₄ = 48.2°). The YO₈ polyhedra are isolated from each other. They are linked by corner-sharing to six Q² type PO₄ tetrahedra and to two Q³ type tetrahedra leading to the three-dimensional framework.

Related literature

Besides crystals of the title compound, crystals of the monoclinic polymorph were also obtained (Mbarek et al., 2009). For isotypic structures, see: Durif (1972) for the Ho member; Katrusiak & Kaczmarek (1995) and Dimitrova et al. (2004) for the Er member. For a review of the crystal chemistry of ultraphosphates, see: Durif (1995). For applications of rare earth ultraphosphates, see: Rao & Devine (2000); Moine & Bizarri (2006). For general background, see: Porai-Koshits & Aslanov (1972).

S2. Experimental

Crystals of the title compounds were synthesized by reacting Y₂O₃ with (NH₄)₂HPO₄ in a graphite crucible. A mixture of these reagents in the molar ratio 1:9 was used for the synthesis. The mixture was first heated at 473 K for 12 h. Then the temperature was raised up to 673 K and was held for 2 days before cooling to room temperature at a rate of 10 K/h. Single-crystals were extracted from the batch by washing with hot water. Besides crystals of the title compound, crystals of the monoclinic polymorph were also obtained (Mbarek et al., 2009).

S3. Refinement

The highest residual peak in the final difference Fourier maps was located 0.26 Å from atom Y1 and the deepest hole was located 0.44 Å from atom P2.

Computing details

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008b); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008b); molecular graphics: CaRIne (Boudias & Monceau, 1998); software used to prepare material for publication: SHELXTL (Sheldrick, 2008b).

Figures

	Fig. 1. Projection along [100] of the structure of YP5O14 showing the isolated ∞(P5O14)^3- ribbons.
	Fig. 2. Details of the ∞(P5O14)^3- ribbon in a projection along [001], symmetry codes: (i) x, -y+1/2, z; (iii) x+1/2, y, -z+1/2; (ix) x+1/2, 1/2-y+1/2, 1/2-z.

yttrium pentaphosphate(V)

Crystal data

YP5O14	F(000) = 904
Mr = 467.76	Dx = 3.136 Mg m^−3
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 3391 reflections
a = 8.7128 (2) Å	θ = 3.6–27.5°
b = 12.7218 (4) Å	µ = 6.79 mm^−1
c = 8.9377 (3) Å	T = 296 K
V = 990.68 (5) Å^3	Platelet, colourless
Z = 4	0.22 × 0.15 × 0.11 mm

Data collection

Bruker APEXII CCD area-detector diffractometer	1194 independent reflections
Radiation source: fine-focus sealed tube	1136 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.019
Detector resolution: 8.3333 pixels mm^-1	θmax = 27.6°, θmin = 2.8°
ϕ and ω scans	h = −7→11
Absorption correction: multi-scan (SADABS; Sheldrick, 2008a)	k = −16→16
Tmin = 0.330, Tmax = 0.460	l = −11→7
5338 measured reflections

Refinement

Refinement on F^2	0 constraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F^2 > 2σ(F^2)] = 0.030	Secondary atom site location: difference Fourier map
wR(F^2) = 0.110	w = 1/[σ^2(Fo^2) + (0.0553P)^2 + 6.1916P] where P = (Fo^2 + 2Fc^2)/3
S = 1.22	(Δ/σ)max < 0.001
1194 reflections	Δρmax = 1.60 e Å^−3
97 parameters	Δρmin = −1.11 e Å^−3
0 restraints

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
Y1	0.01824 (6)	0.2500	0.05695 (6)	0.0042 (2)
P1	0.49261 (13)	0.41750 (10)	−0.20198 (13)	0.0101 (3)
P2	0.4300 (2)	0.2500	0.00645 (18)	0.0117 (4)
P3	−0.24466 (12)	0.43269 (9)	0.22692 (13)	0.0104 (3)
O1	0.2739 (6)	0.2500	−0.0586 (5)	0.0164 (10)
O2	0.5265 (4)	0.3470 (3)	−0.0646 (4)	0.0148 (7)
O3	−0.0382 (6)	0.2500	0.3332 (6)	0.0193 (11)
O4	−0.1756 (4)	0.3732 (3)	0.1035 (4)	0.0166 (7)
O5	0.6146 (4)	0.5051 (3)	−0.1804 (4)	0.0146 (7)
O6	0.1567 (4)	0.3836 (3)	0.1598 (4)	0.0172 (7)
O7	0.3374 (4)	0.4704 (3)	−0.1552 (4)	0.0150 (7)
O8	−0.0066 (4)	0.3649 (3)	−0.1534 (4)	0.0191 (8)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Y1	0.0044 (3)	0.0036 (3)	0.0045 (3)	0.000	−0.00084 (18)	0.000
P1	0.0105 (6)	0.0099 (6)	0.0101 (5)	−0.0001 (4)	0.0002 (4)	0.0000 (4)
P2	0.0129 (8)	0.0116 (8)	0.0107 (8)	0.000	0.0003 (6)	0.000
P3	0.0089 (5)	0.0100 (5)	0.0123 (5)	−0.0004 (4)	0.0002 (4)	−0.0001 (4)
O1	0.012 (2)	0.020 (2)	0.016 (2)	0.000	0.0002 (18)	0.000
O2	0.0141 (16)	0.0138 (17)	0.0165 (17)	−0.0023 (13)	−0.0028 (12)	0.0050 (13)
O3	0.020 (3)	0.022 (3)	0.015 (2)	0.000	0.001 (2)	0.000
O4	0.0158 (16)	0.0187 (17)	0.0154 (15)	0.0041 (14)	0.0008 (13)	−0.0021 (13)
O5	0.0139 (16)	0.0146 (15)	0.0153 (15)	−0.0052 (13)	0.0019 (13)	0.0009 (13)
O6	0.0153 (17)	0.0166 (16)	0.0196 (16)	−0.0025 (13)	−0.0035 (14)	−0.0032 (13)
O7	0.0125 (15)	0.0154 (15)	0.0172 (16)	0.0037 (13)	0.0021 (13)	0.0038 (13)
O8	0.0207 (19)	0.0215 (19)	0.0150 (16)	0.0009 (14)	0.0014 (13)	0.0058 (16)

Geometric parameters (Å, º)

Y1—O6	2.278 (3)	P1—O5	1.553 (3)
Y1—O6^i	2.278 (3)	P1—O7	1.567 (3)
Y1—O4^i	2.341 (3)	P2—O3^iii	1.460 (5)
Y1—O4	2.341 (3)	P2—O1	1.479 (5)
Y1—O8^i	2.391 (4)	P2—O2	1.623 (4)
Y1—O8	2.391 (4)	P2—O2^i	1.623 (4)
Y1—O1	2.455 (5)	P3—O4	1.467 (3)
Y1—O3	2.518 (5)	P3—O6^iv	1.468 (3)
P1—O8^ii	1.455 (4)	P3—O7^v	1.607 (3)
P1—O2	1.549 (4)	P3—O5^vi	1.611 (3)
O6—Y1—O6^i	96.52 (18)	O1—Y1—O3	126.14 (16)
O6—Y1—O4^i	144.08 (12)	O8^ii—P1—O2	115.9 (2)
O6^i—Y1—O4^i	79.10 (13)	O8^ii—P1—O5	115.9 (2)
O6—Y1—O4	79.10 (13)	O2—P1—O5	100.76 (19)
O6^i—Y1—O4	144.08 (12)	O8^ii—P1—O7	116.0 (2)
O4^i—Y1—O4	84.04 (18)	O2—P1—O7	101.63 (19)
O6—Y1—O8^i	145.21 (13)	O5—P1—O7	104.42 (19)
O6^i—Y1—O8^i	84.77 (13)	O3^iii—P2—O1	124.1 (3)
O4^i—Y1—O8^i	70.44 (12)	O3^iii—P2—O2	106.61 (19)
O4—Y1—O8^i	118.93 (12)	O1—P2—O2	108.82 (17)
O6—Y1—O8	84.77 (13)	O3^iii—P2—O2^i	106.61 (19)
O6^i—Y1—O8	145.21 (13)	O1—P2—O2^i	108.82 (17)
O4^i—Y1—O8	118.93 (12)	O2—P2—O2^i	99.0 (3)
O4—Y1—O8	70.44 (12)	O4—P3—O6^iv	122.6 (2)
O8^i—Y1—O8	75.38 (19)	O4—P3—O7^v	107.59 (18)
O6—Y1—O1	71.89 (11)	O6^iv—P3—O7^v	107.87 (19)
O6^i—Y1—O1	71.89 (11)	O4—P3—O5^vi	110.6 (2)
O4^i—Y1—O1	136.82 (9)	O6^iv—P3—O5^vi	105.42 (19)
O4—Y1—O1	136.82 (9)	O7^v—P3—O5^vi	100.51 (18)
O8^i—Y1—O1	75.61 (12)	P2—O1—Y1	132.0 (3)
O8—Y1—O1	75.61 (12)	P1—O2—P2	130.7 (2)
O6—Y1—O3	73.01 (12)	P2^iv—O3—Y1	179.7 (3)
O6^i—Y1—O3	73.01 (12)	P3—O4—Y1	140.8 (2)
O4^i—Y1—O3	71.63 (12)	P1—O5—P3^vii	140.4 (2)
O4—Y1—O3	71.63 (12)	P3^iii—O6—Y1	155.0 (2)
O8^i—Y1—O3	138.88 (10)	P1—O7—P3^v	131.1 (2)
O8—Y1—O3	138.88 (10)	P1^viii—O8—Y1	168.4 (3)

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