A new polymorph of Lu(PO3)3

Bejaoui, A.; Horchani-Naifer, K.; Férid, M.

doi:10.1107/S1600536808021995

inorganic compounds

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Volume 64| Part 8| August 2008| Page i48

doi:10.1107/S1600536808021995

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A new polymorph of Lu(PO₃)₃

Anis Bejaoui,^a Karima Horchani-Naifer ^a and Mokhtar Férid ^a ^*

^aUnité de Recherches de Matériaux de Terres Rares, Centre National de Recherches en Sciences des Matériaux, BP 95 Hammam-Lif 2050, Tunisia
^*Correspondence e-mail: mokhtar.ferid@inrst.rnrt.tn

(Received 23 June 2008; accepted 14 July 2008; online 19 July 2008)

A new polymorph of lutetium polyphosphate, Lu(PO₃)₃, was found to be isotypic with the trigonal form of Yb(PO₃)₃. Two of the three Lu atoms occupy special positions (Wyckoff positions 3a and 3b, site symmetry $[\overline{3}]$ ). The atomic arrangement consists of infinite helical polyphosphate chains running along the c axis, with a repeat period of 12 PO₄ tetrahedra, joined with LuO₆ octahedra.

Related literature

For syntheses and optical properties, see: Briche et al. (2006 ); Jouini, Férid, Gacon, Grosvalet et al. (2003 ); Jouini, Férid, Gacon & Trabelsi-Ayadi (2003 ); Ternane et al. (2005 ); Graia et al. (2003 ); Anisimova et al. (1992 ). For the monoclinic polymorph of Lu(PO₃)₃, see: Höppe & Sedlmaier (2007 ); Yuan et al. (2008 ).

Experimental

Crystal data

Lu(PO₃)₃
M_r = 411.88
Trigonal, $[R \overline 3]$
a = 20.9106 (6) Å
c = 12.0859 (7) Å
V = 4576.6 (3) Å³
Z = 24
Mo Kα radiation
μ = 13.59 mm⁻¹
T = 100 (2) K
0.18 × 0.18 × 0.17 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.102, T_max = 0.104
25139 measured reflections
4170 independent reflections
3609 reflections with I > 2σ(I)
R_int = 0.054

Refinement

R[F² > 2σ(F²)] = 0.032
wR(F²) = 0.060
S = 1.05
4170 reflections
159 parameters
Δρ_max = 2.34 e Å⁻³
Δρ_min = −2.07 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ); cell refinement: APEX2; data reduction: APEX2; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2001 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808021995/fi2065sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808021995/fi2065Isup2.hkl

checkCIF report

Comment top

There is considerable scientific and technological interest in the synthesis, structure, and properties of yttrium and rare earth polyphosphates of the formula Ln(PO₃)₃, because these compounds offer thermal stability and richness of formulations and structures (Briche et al., 2006, Jouini, Férid, Gacon, Grosvalet et al., 2003, Jouini, Férid, Gacon & Trabelsi-Ayadi, 2003, Ternane et al., 2005, Graia et al., 2003). In this paper, we report the preparation and crystal structure refinement of the polyphosphate Lu(PO₃)₃, crystallizing in space group R-3 . The existence of the trigonal polymorph was originally reported by Anisimova for the Yb(PO₃)₃ polyphosphate (Anisimova et al., 1992). The monoclinic polymorph of Lu(PO₃)₃ was recently reported by Höppe and Yuan (Höppe & Sedlmaier, 2007, Yuan et al., 2008). The atomic arrangement of these structures is characterized by a three-dimensional framework built of (PO₃)_n chains that are formed by corner-sharing of PO₄ tetrahedra. These two polymorphs differ by the polyphosphate chains configuration. The chains that were observed in monoclinic Lu(PO₃)₃ form infinite zigzag chains (PO₃)_nthat extend along c with a period of six tetrahedra. In trigonal Lu(PO₃)₃, the (PO₃)_n chains are helical with a period of 12 tetrahedra (Fig.1) and are arranged about the 3₁ helical axis. The chains are joined to each other by LuO₆ octahedra (Fig 2.), no oxygen atom is shared between adjacent LuO₆ octahedra. Figure 3 shows the projection of Lu(PO₃)₃with anisotropic displacement parameters drawn at the 50% probability level.

Related literature top

For syntheses and optical properties, see: Briche et al. (2006); Jouini, Férid, Gacon, Grosvalet et al. (2003); Jouini, Férid, Gacon & Trabelsi-Ayadi (2003); Ternane et al. (2005); Graia et al. (2003); Anisimova et al. (1992). For the monoclinic polymorph of Lu(PO₃)₃, see: Höppe & Sedlmaier (2007); Yuan et al. (2008).

Experimental top

Single crystals of Lu(PO₃)₃ were grown by a flux method. Lutetium oxide was dissolved in an excess of phosphoric acid using the molar ratio Lu:P = 1:20. The resulting solution was heated in a vitreous graphite crucible at 573 K for 5 days. The obtained colourless crystals were then isolated from the acid solution using hot water.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2 (Bruker, 2005); data reduction: APEX2 (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2001); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. A projection of the helical (PO₃)_n chains along b.
	Fig. 2. A projection of Lu(PO₃)₃ along c, showing the arrangement of the LuO₆ octahedra and PO₄ tetrahedra.
	Fig. 3. Projection of the Lu(PO₃)₃ polyphosphate, showing the lutetium coordination with displacement ellipsoids drawn at the 50% probability level. [Symmetry codes : (i) -y, x-y, z; (ii) -x+y, -x, z; (iii)-x+1/3, -y+2/3, -z+2/3; (iv) y+1/3, -x+y+2/3, -z+2/3; (v) x-y+1/3, x+2/3, -z+2/3; (vi) -x, -y, -z; (vii) -x+y+1/3, -x+2/3, z+2/3.]

lutetium polyphosphate top

Crystal data top

Lu(PO₃)₃	D_x = 3.587 Mg m⁻³
M_r = 411.88	Mo Kα radiation, λ = 0.71073 Å
Trigonal, R3	Cell parameters from 25 reflections
Hall symbol: -R 3	θ = 2.8–34.1°
a = 20.9106 (6) Å	µ = 13.59 mm⁻¹
c = 12.0859 (7) Å	T = 100 K
V = 4576.6 (3) Å³	Cube, colourless
Z = 24	0.18 × 0.18 × 0.17 mm
F(000) = 4512

Data collection top

Bruker APEXII CCD area-detector diffractometer	4170 independent reflections
Radiation source: fine-focus sealed tube	3609 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.054
ω scans	θ_max = 34.2°, θ_min = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −32→32
T_min = 0.102, T_max = 0.104	k = −32→32
25139 measured reflections	l = −18→18

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.032	w = 1/[σ²(F_o²) + (0.0212P)²] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.061	(Δ/σ)_max = 0.001
S = 1.05	Δρ_max = 2.34 e Å⁻³
4170 reflections	Δρ_min = −2.07 e Å⁻³
159 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.000061 (8)

Crystal data top

Lu(PO₃)₃	Z = 24
M_r = 411.88	Mo Kα radiation
Trigonal, R3	µ = 13.59 mm⁻¹
a = 20.9106 (6) Å	T = 100 K
c = 12.0859 (7) Å	0.18 × 0.18 × 0.17 mm
V = 4576.6 (3) Å³

Data collection top

Bruker APEXII CCD area-detector diffractometer	4170 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	3609 reflections with I > 2σ(I)
T_min = 0.102, T_max = 0.104	R_int = 0.054
25139 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.032	159 parameters
wR(F²) = 0.061	0 restraints
S = 1.05	Δρ_max = 2.34 e Å⁻³
4170 reflections	Δρ_min = −2.07 e Å⁻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
Lu1	0.6667	0.3333	0.3333	0.00741 (8)
Lu2	0.6667	0.3333	−0.1667	0.01207 (9)
Lu3	0.440661 (9)	0.365196 (10)	0.096806 (14)	0.00780 (5)
P1	0.63820 (6)	0.45920 (6)	0.16119 (9)	0.00821 (19)
P2	0.50313 (6)	0.54494 (6)	0.16810 (9)	0.0096 (2)
P3	0.39267 (6)	0.30556 (6)	0.37383 (10)	0.0111 (2)
P4	0.50120 (6)	0.25039 (6)	−0.01904 (10)	0.0107 (2)
O1	0.44368 (17)	0.46669 (17)	0.1552 (3)	0.0132 (6)
O2	0.34108 (18)	0.22020 (17)	0.3991 (3)	0.0132 (6)
O3	0.54706 (18)	0.58558 (18)	0.0709 (3)	0.0141 (6)
O4	0.45503 (18)	0.27392 (18)	0.0416 (3)	0.0168 (7)
O5	0.55847 (17)	0.42399 (18)	0.1374 (3)	0.0175 (7)
O6	0.45659 (17)	0.19780 (19)	−0.1185 (3)	0.0155 (7)
O7	0.66627 (18)	0.41823 (18)	0.2253 (3)	0.0190 (7)
O8	0.57293 (19)	0.3097 (2)	−0.0609 (3)	0.0247 (8)
O9	0.6655 (2)	0.5377 (2)	0.2137 (4)	0.0351 (11)
O10	0.5156 (2)	0.1948 (2)	0.0471 (3)	0.0315 (10)
O11	0.3569 (2)	0.3473 (2)	0.4088 (4)	0.0298 (9)
O12	0.4182 (3)	0.3127 (2)	0.2586 (3)	0.0364 (11)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Lu1	0.00684 (11)	0.00684 (11)	0.00854 (19)	0.00342 (6)	0.000	0.000
Lu2	0.01014 (13)	0.01014 (13)	0.0159 (2)	0.00507 (6)	0.000	0.000
Lu3	0.00810 (8)	0.00796 (8)	0.00662 (8)	0.00347 (7)	0.00035 (6)	0.00000 (6)
P1	0.0086 (5)	0.0070 (5)	0.0084 (5)	0.0034 (4)	−0.0005 (4)	−0.0006 (4)
P2	0.0133 (5)	0.0095 (5)	0.0072 (5)	0.0065 (4)	−0.0008 (4)	−0.0007 (4)
P3	0.0150 (5)	0.0121 (5)	0.0095 (5)	0.0093 (4)	0.0006 (4)	0.0032 (4)
P4	0.0115 (5)	0.0132 (5)	0.0106 (5)	0.0084 (4)	−0.0009 (4)	0.0000 (4)
O1	0.0157 (15)	0.0117 (14)	0.0132 (15)	0.0076 (13)	0.0006 (12)	−0.0027 (12)
O2	0.0192 (16)	0.0124 (15)	0.0079 (14)	0.0077 (13)	0.0020 (12)	0.0008 (11)
O3	0.0216 (17)	0.0164 (16)	0.0055 (14)	0.0104 (14)	0.0015 (12)	−0.0001 (12)
O4	0.0141 (16)	0.0152 (16)	0.0215 (18)	0.0076 (13)	0.0028 (13)	−0.0036 (13)
O5	0.0089 (14)	0.0147 (16)	0.0269 (19)	0.0044 (13)	−0.0040 (13)	−0.0065 (14)
O6	0.0120 (15)	0.0265 (18)	0.0117 (15)	0.0125 (14)	−0.0042 (12)	−0.0051 (13)
O7	0.0154 (16)	0.0188 (17)	0.0264 (19)	0.0110 (14)	0.0048 (14)	0.0145 (14)
O8	0.0126 (16)	0.027 (2)	0.028 (2)	0.0050 (15)	0.0040 (14)	−0.0063 (16)
O9	0.023 (2)	0.030 (2)	0.060 (3)	0.0199 (18)	−0.019 (2)	−0.030 (2)
O10	0.063 (3)	0.025 (2)	0.021 (2)	0.033 (2)	−0.0207 (19)	−0.0072 (16)
O11	0.0202 (19)	0.0148 (17)	0.058 (3)	0.0114 (15)	0.0067 (18)	−0.0006 (18)
O12	0.063 (3)	0.022 (2)	0.0141 (19)	0.014 (2)	0.0127 (19)	0.0068 (15)

Geometric parameters (Å, º) top

Lu1—O7ⁱ	2.207 (3)	Lu3—O3^x	2.229 (3)
Lu1—O7ⁱⁱ	2.207 (3)	P1—O5	1.475 (3)
Lu1—O7ⁱⁱⁱ	2.207 (3)	P1—O7	1.477 (3)
Lu1—O7^iv	2.207 (3)	P1—O10ⁱⁱⁱ	1.569 (4)
Lu1—O7	2.207 (3)	P1—O9	1.578 (4)
Lu1—O7^v	2.207 (3)	P2—O3	1.472 (3)
Lu2—O8^vi	2.180 (3)	P2—O1	1.488 (3)
Lu2—O8^iv	2.180 (3)	P2—O6^xi	1.585 (3)
Lu2—O8ⁱⁱⁱ	2.180 (3)	P2—O2ⁱⁱ	1.593 (3)
Lu2—O8	2.180 (3)	P3—O11	1.467 (4)
Lu2—O8^vii	2.180 (3)	P3—O12	1.472 (4)
Lu2—O8^viii	2.180 (3)	P3—O9ⁱ	1.573 (4)
Lu3—O11^ix	2.134 (3)	P3—O2	1.587 (3)
Lu3—O12	2.176 (4)	P4—O8	1.478 (4)
Lu3—O4	2.180 (3)	P4—O4	1.478 (3)
Lu3—O5	2.189 (3)	P4—O10	1.560 (4)
Lu3—O1	2.207 (3)	P4—O6	1.581 (3)

O7ⁱ—Lu1—O7ⁱⁱ	88.57 (14)	O4—Lu3—O5	87.21 (12)
O7ⁱ—Lu1—O7ⁱⁱⁱ	180.0	O11^ix—Lu3—O1	91.99 (13)
O7ⁱⁱ—Lu1—O7ⁱⁱⁱ	91.43 (14)	O12—Lu3—O1	95.32 (14)
O7ⁱ—Lu1—O7^iv	91.43 (14)	O4—Lu3—O1	171.70 (12)
O7ⁱⁱ—Lu1—O7^iv	180.0	O5—Lu3—O1	84.56 (12)
O7ⁱⁱⁱ—Lu1—O7^iv	88.57 (14)	O11^ix—Lu3—O3^x	88.69 (15)
O7ⁱ—Lu1—O7	91.43 (14)	O12—Lu3—O3^x	174.96 (15)
O7ⁱⁱ—Lu1—O7	91.43 (14)	O4—Lu3—O3^x	95.25 (12)
O7ⁱⁱⁱ—Lu1—O7	88.57 (14)	O5—Lu3—O3^x	96.14 (13)
O7^iv—Lu1—O7	88.57 (14)	O1—Lu3—O3^x	84.56 (12)
O7ⁱ—Lu1—O7^v	88.57 (14)	O5—P1—O7	119.4 (2)
O7ⁱⁱ—Lu1—O7^v	88.57 (14)	O5—P1—O10ⁱⁱⁱ	106.7 (2)
O7ⁱⁱⁱ—Lu1—O7^v	91.43 (14)	O7—P1—O10ⁱⁱⁱ	110.3 (2)
O7^iv—Lu1—O7^v	91.43 (14)	O5—P1—O9	109.15 (19)
O7—Lu1—O7^v	180.0	O7—P1—O9	110.6 (2)
O8^vi—Lu2—O8^iv	180.0	O10ⁱⁱⁱ—P1—O9	98.7 (3)
O8^vi—Lu2—O8ⁱⁱⁱ	90.92 (15)	O3—P2—O1	119.23 (19)
O8^iv—Lu2—O8ⁱⁱⁱ	89.08 (15)	O3—P2—O6^xi	105.71 (18)
O8^vi—Lu2—O8	90.92 (15)	O1—P2—O6^xi	109.44 (19)
O8^iv—Lu2—O8	89.08 (15)	O3—P2—O2ⁱⁱ	112.19 (18)
O8ⁱⁱⁱ—Lu2—O8	89.08 (15)	O1—P2—O2ⁱⁱ	106.01 (18)
O8^vi—Lu2—O8^vii	89.08 (15)	O6^xi—P2—O2ⁱⁱ	103.12 (18)
O8^iv—Lu2—O8^vii	90.92 (15)	O11—P3—O12	118.6 (3)
O8ⁱⁱⁱ—Lu2—O8^vii	180.0	O11—P3—O9ⁱ	105.0 (2)
O8—Lu2—O8^vii	90.92 (15)	O12—P3—O9ⁱ	108.6 (3)
O8^vi—Lu2—O8^viii	89.08 (15)	O11—P3—O2	110.6 (2)
O8^iv—Lu2—O8^viii	90.92 (15)	O12—P3—O2	107.7 (2)
O8ⁱⁱⁱ—Lu2—O8^viii	90.92 (15)	O9ⁱ—P3—O2	105.49 (19)
O8—Lu2—O8^viii	180.0	O8—P4—O4	116.6 (2)
O8^vii—Lu2—O8^viii	89.08 (15)	O8—P4—O10	107.9 (2)
O11^ix—Lu3—O12	86.28 (18)	O4—P4—O10	113.3 (2)
O11^ix—Lu3—O4	96.31 (13)	O8—P4—O6	108.8 (2)
O12—Lu3—O4	85.59 (14)	O4—P4—O6	110.62 (18)
O11^ix—Lu3—O5	173.76 (15)	O10—P4—O6	97.91 (19)
O12—Lu3—O5	88.86 (16)

Symmetry codes: (i) x−y+1/3, x−1/3, −z+2/3; (ii) y+1/3, −x+y+2/3, −z+2/3; (iii) −x+y+1, −x+1, z; (iv) −y+1, x−y, z; (v) −x+4/3, −y+2/3, −z+2/3; (vi) y+1/3, −x+y+2/3, −z−1/3; (vii) x−y+1/3, x−1/3, −z−1/3; (viii) −x+4/3, −y+2/3, −z−1/3; (ix) −x+y+1/3, −x+2/3, z−1/3; (x) −x+1, −y+1, −z; (xi) −y+2/3, x−y+1/3, z+1/3.

Experimental details

Crystal data
Chemical formula	Lu(PO₃)₃
M_r	411.88
Crystal system, space group	Trigonal, R3
Temperature (K)	100
a, c (Å)	20.9106 (6), 12.0859 (7)
V (Å³)	4576.6 (3)
Z	24
Radiation type	Mo Kα
µ (mm⁻¹)	13.59
Crystal size (mm)	0.18 × 0.18 × 0.17

Data collection
Diffractometer	Bruker APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.102, 0.104
No. of measured, independent and observed [I > 2σ(I)] reflections	25139, 4170, 3609
R_int	0.054
(sin θ/λ)_max (Å⁻¹)	0.790

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.032, 0.061, 1.05
No. of reflections	4170
No. of parameters	159
Δρ_max, Δρ_min (e Å⁻³)	2.34, −2.07

Computer programs: APEX2 (Bruker, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2001).

Acknowledgements

This work was supported by the Ministry of Higher Education, Scientific Research and Technology of Tunisia.

References

Anisimova, N. Y., Trunov, V. K., Karamanovskaya, N. B. & Chudinova, N. N. (1992). Neorg. Mater. 28, 441–444. CAS Google Scholar
Brandenburg, K. (2001). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Briche, S., Zambon, D., Boyer, D., Chadeyron, G. & Mahiou, R. (2006). Opt. Mater. 28, 615–620. Web of Science CrossRef CAS Google Scholar
Bruker (2005). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Graia, M., Driss, A. & Jouini, T. (2003). Solid State Sci. 5, 393–402. Web of Science CrossRef CAS Google Scholar
Höppe, H. A. & Sedlmaier, S. J. (2007). Inorg. Chem. 46, 3467–3474. Web of Science PubMed Google Scholar
Jouini, A., Férid, M., Gacon, J. C., Grosvalet, L., Thozet, A. & Trabelsi-Ayadi, M. (2003). Mater. Res. Bull. 38, 1613–1622. Web of Science CrossRef CAS Google Scholar
Jouini, A., Férid, M., Gacon, J. C. & Trabelsi-Ayadi, M. (2003). Opt. Mater. 24, 175–180. Web of Science CrossRef CAS Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Ternane, R., Férid, M., Panczer, G., Trabelsi-Ayadi, M. & Boulon, G. (2005). Opt. Mater. 27, 1832–1838. Web of Science CrossRef CAS Google Scholar
Yuan, J. L., Zhang, H., Zhao, J. T., Chen, H. H., Yang, X. X. & Zhang, G. B. (2008). Opt. Mater. 30, 1369–1374. Web of Science CrossRef CAS Google Scholar