Ammonium ytterbium(III) diphosphate(V)

Fejfarová, K.; Essehli, R.; El Bali, B.; Dušek, M.

doi:10.1107/S1600536808039664

inorganic compounds

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Volume 64| Part 12| December 2008| Pages i85-i86

doi:10.1107/S1600536808039664

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Ammonium ytterbium(III) diphosphate(V)

Karla Fejfarová,^a Rachid Essehli,^b Brahim El Bali ^b and Michal Dušek ^a ^*

^aInstitute of Physics, Na Slovance 2, 182 21 Praha 8, Czech Republic, and ^bDepartment of Chemistry, Faculty of Sciences, University Mohammed 1st, PO Box 717, 60 000 Oujda, Morocco
^*Correspondence e-mail: fejfarov@fzu.cz

(Received 21 November 2008; accepted 25 November 2008; online 29 November 2008)

The title compound, NH₄YbP₂O₇, crystallizes in the KAlP₂O₇ structure type and consists of distorted YbO₆ octahedra and bent P₂O₇⁴⁻ diphosphate units forming together a three-dimensional network. There are channels in the structure running along the c axis, where the NH₄⁺ cations are located. They are connected via N—H⋯O hydrogen bonds to the terminal O atoms of the diphosphate anions.

Related literature

Isotypic compounds were reported by Man-Rong et al. (2005 ), [NH₄LuP₂O₇]; Horchani-Naifer & Férid (2007 ), [YbP₂O₇]; Jansen et al. (1991 ), [CsYbP₂O₇], that all crystallize with the KAlP₂O₇ structure type (Ng & Calvo, 1973 ). For the crystal structures of other isoformular rare earth diphosphates, see: Hamady & Jouini (1996 ), [NaYP₂O₇]; Férid et al. (2004 ), [NaEuP₂O₇]; Ferid et al. (2004 ), [NaYbP₂O₇]; Férid & Horchani-Naifer (2004 ), [NaLaP₂O₇]; Horchani-Naifer & Férid (2005 ), [NaCeP₂O₇]; Hamady et al. (1994 ) and Yuan et al. (2007 ), [KYP₂O₇]. Possible applications of rare earth phosphates were discussed by Yamada et al. (1974 ); Hong (1975 ); Bimberg et al. (1975 ). For background on crystallographic software, see: Becker & Coppens (1974 ).

Experimental

Crystal data

NH₄YbP₂O₇
M_r = 365
Monoclinic, P 2₁ /c
a = 7.6468 (2) Å
b = 10.9119 (2) Å
c = 8.6129 (3) Å
β = 105.645 (3)°
V = 692.04 (3) Å³
Z = 4
Mo Kα radiation
μ = 13.97 mm⁻¹
T = 120 K
0.26 × 0.08 × 0.07 mm

Data collection

Oxford Diffraction XCalibur 2 diffractometer with Sapphire 2 area detector
Absorption correction: analytical [implemented in CrysAlis RED (Oxford Diffraction, 2008 $[Oxford Diffraction (2008). CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]$ ), according to Clark & Reid (1995 )] T_min = 0.169, T_max = 0.545
8574 measured reflections
1437 independent reflections
1362 reflections with I > 3σ(I)
R_int = 0.023

Refinement

R[F² > 2σ(F²)] = 0.016
wR(F²) = 0.061
S = 1.32
1437 reflections
113 parameters
4 restraints
Only H-atom coordinates refined
Δρ_max = 0.58 e Å⁻³
Δρ_min = −0.50 e Å⁻³

Table 1
Selected geometric parameters (Å, °)

Yb1—O1	2.240 (3)
Yb1—O2ⁱ	2.158 (4)
Yb1—O4ⁱⁱ	2.230 (3)
Yb1—O5	2.224 (3)
Yb1—O6ⁱⁱⁱ	2.191 (4)
Yb1—O7^iv	2.195 (3)
P1—O1	1.529 (3)
P1—O2	1.498 (5)
P1—O3	1.611 (4)
P1—O4	1.525 (3)
P2—O3	1.622 (4)
P2—O5	1.532 (3)
P2—O6	1.507 (4)
P2—O7	1.514 (3)

P1—O3—P2	127.40 (19)
Symmetry codes: (i) $[x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (ii) $[-x+1, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (iii) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (iv) $[-x+2, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O7^v	0.87 (4)	2.52 (5)	3.381 (5)	168 (4)
N1—H2⋯O4^vi	0.88 (4)	2.03 (5)	2.888 (5)	166 (4)
N1—H3⋯O5^vii	0.87 (4)	2.00 (4)	2.873 (6)	177 (7)
N1—H4⋯O1	0.86 (5)	2.26 (4)	2.916 (5)	132 (4)
Symmetry codes: (v) x-1, y, z; (vi) -x+1, -y+1, -z+1; (vii) $[x-1, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ .

Data collection: CrysAlis CCD (Oxford Diffraction, 2005 $[Oxford Diffraction (2005). CrysAlis CCD. Oxford Diffraction Ltd, Abingdon, England.]$ ); cell refinement: CrysAlis RED (Oxford Diffraction, 2008 $[Oxford Diffraction (2008). CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]$ ); data reduction: CrysAlis RED; program(s) used to solve structure: SIR2002 (Burla et al., 2003 ); program(s) used to refine structure: JANA2006 (Petříček et al., 2007 ); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ); software used to prepare material for publication: JANA2006.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808039664/wm2208sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808039664/wm2208Isup2.hkl

checkCIF report

Comment top

Rare earth phosphates have many potential applications in the field of optical materials including laser phosphors (Yamada et al., 1974; Hong, 1975; Bimberg et al., 1975). Their crystal structures depend on the ionic radii of the alkali metal and the rare earth ions. The two AYbP₂O₇ (A = Cs (Jansen et al., 1991), K (Horchani-Naifer & Férid, 2007)) structures known so far belong to the KAlP₂O₇ structure type (Ng & Calvo, 1973) and crystallize in space group P2₁/c. For the correspondent isoformular sodium rare earth diphosphates, several other structures have been described, for instance NaYP₂O₇ in space group P2₁ (Hamady & Jouini, 1996), NaLnP₂O₇ (Ln = Eu (Férid, Horchani & Amami, 2004), Yb (Ferid et al., 2004)) in space group P2₁/n, and NaLnP₂O₇ (Ln = La (Férid & Horchani-Naifer, 2004), Ce (Horchani-Naifer & Férid, 2005) in space group Pnma. KYP₂O₇ is dimorphic and can adopt the KAlP₂O₇ structure type (Yuan et al., 2007), or a structure in space group Cmcm (Hamady et al., 1994).

In the present paper we report the crystal structure of NH₄YbP₂O₇. This compound is isotypic with NH₄LuP₂O₇ (Man-Rong et al. 2005), KYbP₂O₇ (Horchani-Naifer & Férid, 2007) and CsYbP₂O₇ (Jansen et al., 1991). The Yb atom is coordinated by six oxygen atoms forming a distorted octahedron that belong to five symmetry-related P₂O₇^4- anions (Fig. 1). The average Yb—O bond lenght is 2.206 Å (Table 1). The diphosphate anion is bent with a bridging angle of 127.40 (19) °. The three-dimensional network of YbO₆ and P₂O₇^4- units forms channels running along the c direcion in which the NH₄⁺ cations are located (Fig. 2). Each NH₄⁺ cation is connected via N—H···O hydrogen bonds to four different P₂O₇^4- anions (Table 2).

Related literature top

Isotypic compounds were reported by Man-Rong et al. (2005), [NH₄LuP₂O₇]; Horchani-Naifer & Férid (2007), [YbP₂O₇]; Jansen et al. (1991), [CsYbP₂O₇], that all crystallize with the KAlP₂O₇ structure type (Ng & Calvo, 1973). For the crystal structures of other isoformular rare earth diphosphates, see: Hamady & Jouini (1996), [NaYP₂O₇]; Férid, Horchani & Amami (2004), [NaEuP₂O₇]; Férid et al. (2004), [NaYbP₂O₇]; Férid & Horchani-Naifer (2004), [NaLaP₂O₇]; Horchani-Naifer & Férid (2005), [NaCeP₂O₇]; Hamady et al. (1994) and Yuan et al. (2007), [KYP₂O₇]. Possible applications of rare earth phosphates were discussed by Yamada et al. (1974); Hong (1975); Bimberg et al. (1975). For background on crystallographic software, see: Becker & Coppens (1974). For related literature, see: Ferid et al. (2004).

Experimental top

Three solutions have been mixed in a beaker to prepare the title compound: NH₄OH (20 ml, 0.1 mmol), YbCl₃^.6H₂O (20 ml, 0.1 mmol) and Na₄P₂O₇ (20 ml, 0.1 mmol). The pH of the mixture was controlled with diluted hydrochloric acid to be slightly acidic, and the solution was stirred for two hours at room temperature. Crystals suitable for X-ray analysis were formed after a few days.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2005); cell refinement: CrysAlis RED (Oxford Diffraction, 2008); data reduction: CrysAlis RED (Oxford Diffraction, 2008); program(s) used to solve structure: SIR2002 (Burla et al., 2003); program(s) used to refine structure: JANA2006 (Petříček et al., 2007); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: JANA2006 (Petříček et al., 2007).

Figures top

	Fig. 1. Part of the structure of NH₄YbP₂O_7. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (i) 1 - x,-1/2 + y, 1.5 - z; (ii) x, 0.5 - y, -1/2 + z; (iii) x, 0.5 - y, 1/2 + z; (iv) 2 - x, -1/2 + y, 1.5 - z; (v) 1 - x, 1 - y, 1 - z; (vi} -1 + x, 0.5 - y, -1/2 + z; (vii) -1 + x, y, z.]
	Fig. 2. The packing of NH₄YbP₂O₇ viewed along c. Colors: Pink (P₂O₇), grey (YbO₆), blue balls (N), black balls (H).

Ammonium ytterbium(III) diphosphate(V) top

Crystal data top

NH₄YbP₂O₇	F(000) = 668
M_r = 365	D_x = 3.502 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 8929 reflections
a = 7.6468 (2) Å	θ = 2.8–26.5°
b = 10.9119 (2) Å	µ = 13.97 mm⁻¹
c = 8.6129 (3) Å	T = 120 K
β = 105.645 (3)°	Prism, colorless
V = 692.04 (3) Å³	0.26 × 0.08 × 0.07 mm
Z = 4

Data collection top

Oxford Diffraction XCalibur 2 with Sapphire 2 area detector diffractometer	1437 independent reflections
Radiation source: X-ray tube	1362 reflections with I > 3σ(I)
Graphite monochromator	R_int = 0.023
Detector resolution: 8.3438 pixels mm^-1	θ_max = 26.5°, θ_min = 2.8°
Rotation method data acquisition using ω scans	h = −9→9
Absorption correction: analytical [implemented in CrysAlis RED (Oxford Diffraction, 2008), according to Clark & Reid (1995)]	k = −13→13
T_min = 0.169, T_max = 0.545	l = −10→10
8574 measured reflections

Refinement top

Refinement on F²	Only H-atom coordinates refined
R[F² > 2σ(F²)] = 0.016	Weighting scheme based on measured s.u.'s w = 1/[σ²(I) + 0.0016I²]
wR(F²) = 0.061	(Δ/σ)_max = 0.039
S = 1.32	Δρ_max = 0.58 e Å⁻³
1437 reflections	Δρ_min = −0.50 e Å⁻³
113 parameters	Extinction correction: B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974)
4 restraints	Extinction coefficient: 170 (60)
4 constraints

Crystal data top

NH₄YbP₂O₇	V = 692.04 (3) Å³
M_r = 365	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 7.6468 (2) Å	µ = 13.97 mm⁻¹
b = 10.9119 (2) Å	T = 120 K
c = 8.6129 (3) Å	0.26 × 0.08 × 0.07 mm
β = 105.645 (3)°

Data collection top

Oxford Diffraction XCalibur 2 with Sapphire 2 area detector diffractometer	1437 independent reflections
Absorption correction: analytical [implemented in CrysAlis RED (Oxford Diffraction, 2008), according to Clark & Reid (1995)]	1362 reflections with I > 3σ(I)
T_min = 0.169, T_max = 0.545	R_int = 0.023
8574 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.016	4 restraints
wR(F²) = 0.061	Only H-atom coordinates refined
S = 1.32	Δρ_max = 0.58 e Å⁻³
1437 reflections	Δρ_min = −0.50 e Å⁻³
113 parameters

Special details top

Refinement. The refinement was carried out against all reflections. The conventional R-factor is always based on F. The goodness of fit as well as the weighted R-factor are based on F and F² for refinement carried out on F and F², respectively. The threshold expression is used only for calculating R-factors etc. and it is not relevant to the choice of reflections for refinement.

The program used for refinement, Jana2006, uses the weighting scheme based on the experimental expectations, see _refine_ls_weighting_details, that does not force S to be one. Therefore the values of S are usually larger than the ones from the SHELX program.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Yb1	0.73470 (3)	0.100256 (15)	0.753623 (18)	0.00555 (9)
P1	0.63175 (18)	0.40147 (9)	0.81812 (14)	0.0080 (4)
P2	0.93914 (15)	0.36312 (10)	0.68708 (13)	0.0070 (3)
O1	0.5777 (4)	0.2746 (3)	0.7457 (4)	0.0124 (10)
O2	0.6416 (6)	0.4080 (3)	0.9940 (5)	0.0254 (14)
O3	0.8335 (4)	0.4300 (3)	0.8037 (4)	0.0126 (9)
O4	0.5107 (4)	0.5010 (3)	0.7202 (3)	0.0097 (9)
O5	0.9555 (4)	0.2277 (3)	0.7359 (4)	0.0121 (10)
O6	0.8260 (6)	0.3855 (3)	0.5169 (5)	0.0183 (12)
O7	1.1241 (4)	0.4235 (3)	0.7273 (4)	0.0142 (10)
N1	0.3131 (6)	0.3233 (4)	0.4381 (5)	0.0183 (13)
H1	0.281 (7)	0.348 (5)	0.523 (4)	0.0219*
H2	0.365 (7)	0.385 (3)	0.403 (6)	0.0219*
H3	0.206 (4)	0.306 (5)	0.375 (5)	0.0219*
H4	0.373 (7)	0.267 (4)	0.501 (5)	0.0219*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Yb1	0.00611 (15)	0.00443 (15)	0.00616 (16)	−0.00018 (5)	0.00173 (9)	0.00025 (5)
P1	0.0101 (6)	0.0088 (6)	0.0056 (5)	0.0056 (4)	0.0027 (5)	−0.0006 (4)
P2	0.0066 (5)	0.0058 (5)	0.0084 (5)	−0.0016 (4)	0.0017 (4)	0.0016 (4)
O1	0.0142 (16)	0.0076 (15)	0.0178 (16)	0.0019 (12)	0.0085 (13)	0.0023 (12)
O2	0.034 (3)	0.039 (2)	0.0043 (17)	0.0210 (17)	0.0062 (17)	0.0013 (14)
O3	0.0073 (15)	0.0117 (14)	0.0158 (16)	0.0000 (12)	−0.0019 (13)	−0.0036 (13)
O4	0.0093 (14)	0.0097 (13)	0.0102 (14)	0.0026 (12)	0.0028 (11)	0.0041 (12)
O5	0.0088 (15)	0.0113 (15)	0.0166 (16)	−0.0007 (12)	0.0041 (12)	0.0045 (12)
O6	0.017 (2)	0.0277 (19)	0.0086 (18)	−0.0005 (14)	0.0015 (15)	0.0090 (14)
O7	0.0093 (16)	0.0101 (13)	0.0228 (17)	−0.0036 (13)	0.0035 (14)	0.0014 (12)
N1	0.017 (2)	0.021 (2)	0.013 (2)	−0.0069 (17)	−0.0014 (17)	0.0046 (16)

Geometric parameters (Å, º) top

Yb1—O1	2.240 (3)	P1—O4	1.525 (3)
Yb1—O2ⁱ	2.158 (4)	P2—O3	1.622 (4)
Yb1—O4ⁱⁱ	2.230 (3)	P2—O5	1.532 (3)
Yb1—O5	2.224 (3)	P2—O6	1.507 (4)
Yb1—O6ⁱⁱⁱ	2.191 (4)	P2—O7	1.514 (3)
Yb1—O7^iv	2.195 (3)	N1—H1	0.87 (5)
P1—O1	1.529 (3)	N1—H2	0.87 (5)
P1—O2	1.498 (5)	N1—H3	0.87 (3)
P1—O3	1.611 (4)	N1—H4	0.86 (4)

O1—Yb1—O2ⁱ	88.83 (13)	O2—P1—O3	106.3 (2)
O1—Yb1—O4ⁱⁱ	87.53 (11)	O2—P1—O4	112.5 (2)
O1—Yb1—O5	82.94 (12)	O3—P1—O4	105.70 (17)
O1—Yb1—O6ⁱⁱⁱ	89.43 (12)	O3—P2—O5	106.33 (19)
O1—Yb1—O7^iv	175.63 (13)	O3—P2—O6	106.2 (2)
O2ⁱ—Yb1—O4ⁱⁱ	91.87 (14)	O3—P2—O7	104.64 (18)
O2ⁱ—Yb1—O5	89.99 (15)	O5—P2—O6	113.98 (18)
O2ⁱ—Yb1—O6ⁱⁱⁱ	178.23 (14)	O5—P2—O7	110.79 (17)
O2ⁱ—Yb1—O7^iv	93.37 (13)	O6—P2—O7	114.1 (2)
O4ⁱⁱ—Yb1—O5	170.25 (11)	P1—O3—P2	127.40 (19)
O4ⁱⁱ—Yb1—O6ⁱⁱⁱ	88.39 (13)	P1—O4—H2^v	115.2 (13)
O4ⁱⁱ—Yb1—O7^iv	88.63 (12)	P2—O5—H3^vi	109.5 (14)
O5—Yb1—O6ⁱⁱⁱ	89.47 (13)	H1—N1—H2	108 (5)
O5—Yb1—O7^iv	100.82 (12)	H1—N1—H3	99 (4)
O6ⁱⁱⁱ—Yb1—O7^iv	88.39 (12)	H1—N1—H4	85 (5)
O1—P1—O2	113.0 (2)	H2—N1—H3	113 (4)
O1—P1—O3	107.61 (19)	H2—N1—H4	123 (5)
O1—P1—O4	111.26 (16)	H3—N1—H4	119 (4)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O7^vii	0.87 (4)	2.52 (5)	3.381 (5)	168 (4)
N1—H2···O4^v	0.88 (4)	2.03 (5)	2.888 (5)	166 (4)
N1—H3···O5^viii	0.87 (4)	2.00 (4)	2.873 (6)	177 (7)
N1—H4···O1	0.86 (5)	2.26 (4)	2.916 (5)	132 (4)

Symmetry codes: (v) −x+1, −y+1, −z+1; (vii) x−1, y, z; (viii) x−1, −y+1/2, z−1/2.

Experimental details

Crystal data
Chemical formula	NH₄YbP₂O₇
M_r	365
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	120
a, b, c (Å)	7.6468 (2), 10.9119 (2), 8.6129 (3)
β (°)	105.645 (3)
V (Å³)	692.04 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	13.97
Crystal size (mm)	0.26 × 0.08 × 0.07

Data collection
Diffractometer	Oxford Diffraction XCalibur 2 with Sapphire 2 area detector diffractometer
Absorption correction	Analytical [implemented in CrysAlis RED (Oxford Diffraction, 2008), according to Clark & Reid (1995)]
T_min, T_max	0.169, 0.545
No. of measured, independent and observed [I > 3σ(I)] reflections	8574, 1437, 1362
R_int	0.023
(sin θ/λ)_max (Å⁻¹)	0.628

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.016, 0.061, 1.32
No. of reflections	1437
No. of parameters	113
No. of restraints	4
H-atom treatment	Only H-atom coordinates refined
Δρ_max, Δρ_min (e Å⁻³)	0.58, −0.50

Computer programs: CrysAlis CCD (Oxford Diffraction, 2005), CrysAlis RED (Oxford Diffraction, 2008), SIR2002 (Burla et al., 2003), JANA2006 (Petříček et al., 2007), DIAMOND (Brandenburg & Putz, 2005).

Selected geometric parameters (Å, º) top

Yb1—O1	2.240 (3)	P1—O2	1.498 (5)
Yb1—O2ⁱ	2.158 (4)	P1—O3	1.611 (4)
Yb1—O4ⁱⁱ	2.230 (3)	P1—O4	1.525 (3)
Yb1—O5	2.224 (3)	P2—O3	1.622 (4)
Yb1—O6ⁱⁱⁱ	2.191 (4)	P2—O5	1.532 (3)
Yb1—O7^iv	2.195 (3)	P2—O6	1.507 (4)
P1—O1	1.529 (3)	P2—O7	1.514 (3)

P1—O3—P2	127.40 (19)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O7^v	0.87 (4)	2.52 (5)	3.381 (5)	168 (4)
N1—H2···O4^vi	0.88 (4)	2.03 (5)	2.888 (5)	166 (4)
N1—H3···O5^vii	0.87 (4)	2.00 (4)	2.873 (6)	177 (7)
N1—H4···O1	0.86 (5)	2.26 (4)	2.916 (5)	132 (4)

Symmetry codes: (v) x−1, y, z; (vi) −x+1, −y+1, −z+1; (vii) x−1, −y+1/2, z−1/2.

Acknowledgements

We acknowledge the Grant Agency of the Czech Republic for grant No. 202/06/0757.

References

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