Sr(3)(Al(3+x)Si(13-x))(N(21-x)O(2+x)):Eu (x ∼ 0): a monoclinic modification of Sr-sialon.

The structure of the title compound, Sr-bearing oxonitrido-aluminosilicate (Sr-sialon), contains two types of channels running along the a axis, with the three unique Sr atoms (coordinatioon number seven) residing in the larger one. The channels cross a three-dimensional Si-Al-O-N network, in which the Si and Al atoms are in a tetra-hedral coordination with N and O atoms. The chemical composition of the crystal is close to Sr(3)Al(3)Si(13)N(21)O(2) (tris-trontium trialuminium trideca-silicon henicosa-nitride dioxide), which can be expressed as a mixture of SrSiN(2), Si(3)N(4), AlN, and SiO(2) components in the molar ratio 3:3:3:1. The crystal studied was metrically orthorhombic, consisting of four twin components related by metric merohedry.

Related literature

For the isotypic Eu-bearing oxonitridoaluminosilicate (Eu-sialon) Eu3Al3+Si13-N21-O2+ (x = 1/3), see: Michiue et al. (2009 ▶). For the closely related Sr-bearing sialon structure Sr5Al5+Si21-N35-O2+:Eu2+ (x ∼ 0), see: Oeckler et al. (2009 ▶). For the twin analysis, see: Coch (2004 ▶); Nespolo (2004 ▶). Ionic radii were taken from Shannon (1976 ▶).

Experimental

Crystal data

Sr3Al3Si13N21O2

M = 2081.94

Monoclinic,

a = 14.7557 (5) Å

b = 7.4627 (2) Å

c = 9.0348 (3) Å

β = 90°

V = 994.89 (5) Å3

Z = 1

Mo Kα radiation

μ = 9.05 mm−1

T = 296 K

0.08 × 0.08 × 0.01 mm

Data collection

Bruker APEXII CCD diffractometer

Absorption correction: numerical (de Meulenaer & Tompa, 1965 ▶) T min = 0.532, T max = 0.915

11854 measured reflections

4384 independent reflections

3672 reflections with I > 2σ(I)

R int = 0.036

Refinement

R[F 2 > 2σ(F 2)] = 0.045

wR(F 2) = 0.105

S = 1.07

4384 reflections

162 parameters

1 restraint

Δρmax = 1.33 e Å−3

Δρmin = −1.25 e Å−3

Absolute structure: Flack (1983 ▶), 1942 Friedel pairs

Flack parameter: 0.00

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ATOMS (Dowty, 2008 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810003223/br2134sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810003223/br2134Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Sr3Al3Si13N21O2	F(000) = 1001.0
Mr = 2081.94	Dx = 3.475 Mg m−3
Monoclinic, P1121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c	Cell parameters from 3169 reflections
a = 14.7557 (5) Å	θ = 4.5–35.7°
b = 7.4627 (2) Å	µ = 9.05 mm−1
c = 9.0348 (3) Å	T = 296 K
β = 90°	Plate, light yellow
V = 994.89 (5) Å3	0.08 × 0.08 × 0.01 mm
Z = 1

Bruker APEXII CCD diffractometer	4384 independent reflections
Radiation source: fine-focus sealed tube	3672 reflections with I > 2σ(I)
graphite	Rint = 0.036
φ and ω scans	θmax = 27.5°, θmin = 1.4°
Absorption correction: numerical (Meulenaer & Tompa, 1965)	h = −18→19
Tmin = 0.532, Tmax = 0.915	k = −9→9
11854 measured reflections	l = −11→11

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)] = 0.045	w = 1/[σ2(Fo2) + (0.0316P)2 + 7.9067P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.105	(Δ/σ)max < 0.001
S = 1.07	Δρmax = 1.33 e Å−3
4384 reflections	Δρmin = −1.25 e Å−3
162 parameters	Absolute structure: Flack (1983), 1942 Friedel pairs
1 restraint	Flack parameter: 0.00

Geometry. Atom labels of Al and O are used for the Si(Al) and N(O) mixed sites, respectively, to distinguish them from the pure Si and N sites in Geometric parameters. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
Sr1	0.7496 (2)	0.7488 (2)	0.5178 (4)	0.0275 (3)
Sr2	0.91735 (19)	1.2554 (2)	1.00147 (13)	0.0361 (8)	0.943 (11)
Eu2	0.91735 (19)	1.2554 (2)	1.00147 (13)	0.0361 (8)	0.057 (11)
Sr3	0.58236 (18)	1.2652 (2)	1.03237 (15)	0.0390 (8)	0.963 (11)
Eu3	0.58236 (18)	1.2652 (2)	1.03237 (15)	0.0390 (8)	0.037 (11)
Si1	0.9992 (3)	0.1230 (6)	0.6686 (5)	0.00785 (14)*
Si2	0.8011 (3)	1.1316 (6)	0.6707 (4)	0.00785 (14)*
Si3	0.5002 (3)	0.8635 (5)	0.8784 (5)	0.00785 (14)*
Si4	0.6000 (3)	1.1307 (4)	0.6782 (4)	0.00785 (14)*
Si5	0.6989 (3)	0.8634 (6)	0.8770 (4)	0.00785 (14)*
Si6	0.8019 (3)	0.8726 (6)	0.1733 (5)	0.00785 (14)*
Si7	0.6983 (3)	1.1443 (5)	0.3783 (4)	0.00785 (14)*
Si8	0.6021 (3)	0.8640 (4)	1.1774 (3)	0.00785 (14)*
Si9	0.8979 (3)	1.1420 (4)	0.3693 (4)	0.00785 (14)*
Si10	0.8997 (3)	0.8467 (4)	0.8744 (3)	0.00785 (14)*
Si11	0.9081 (4)	0.4859 (5)	0.6769 (4)	0.0089 (2)*	0.50
Al11	0.9081 (4)	0.4859 (5)	0.6769 (4)	0.0089 (2)*	0.50
Si12	0.9111 (3)	0.5575 (5)	0.3255 (4)	0.0089 (2)*	0.50
Al12	0.9111 (3)	0.5575 (5)	0.3255 (4)	0.0089 (2)*	0.50
Si13	0.5914 (3)	0.4893 (5)	0.3518 (4)	0.0089 (2)*	0.50
Al13	0.5914 (3)	0.4893 (5)	0.3518 (4)	0.0089 (2)*	0.50
Si14	0.5930 (4)	0.5559 (5)	0.7048 (4)	0.0089 (2)*	0.50
Al14	0.5930 (4)	0.5559 (5)	0.7048 (4)	0.0089 (2)*	0.50
Si15	0.7794 (5)	0.5102 (12)	0.8496 (9)	0.0031 (4)*	0.25
Al15	0.7794 (5)	0.5102 (12)	0.8496 (9)	0.0031 (4)*	0.25
Si16	0.7174 (5)	0.4400 (10)	0.8280 (8)	0.0031 (4)*	0.25
Al16	0.7174 (5)	0.4400 (10)	0.8280 (8)	0.0031 (4)*	0.25
Si17	0.7759 (5)	0.4455 (10)	0.1969 (8)	0.0031 (4)*	0.25
Al17	0.7759 (5)	0.4455 (10)	0.1969 (8)	0.0031 (4)*	0.25
Si18	0.7234 (5)	0.5127 (11)	0.1785 (9)	0.0031 (4)*	0.25
Al18	0.7234 (5)	0.5127 (11)	0.1785 (9)	0.0031 (4)*	0.25
N1	0.5017 (7)	0.9760 (14)	1.2397 (11)	0.0108 (3)*
N2	0.6002 (7)	0.9021 (10)	0.9819 (9)	0.0108 (3)*
N3	0.7020 (7)	0.9704 (14)	0.2475 (11)	0.0108 (3)*
N4	1.0012 (10)	0.3442 (18)	0.7379 (15)	0.0108 (3)*
N5	0.8092 (8)	1.3587 (16)	0.7131 (11)	0.0108 (3)*
N6	0.6873 (9)	1.3573 (19)	0.3056 (15)	0.0108 (3)*
N7	0.7989 (7)	1.1040 (13)	0.4784 (12)	0.0108 (3)*
N8	0.8076 (9)	0.6538 (19)	0.2477 (15)	0.0108 (3)*
N9	0.6904 (9)	0.6535 (18)	0.7795 (13)	0.0108 (3)*
N10	0.9000 (8)	1.0199 (10)	0.7380 (8)	0.0108 (3)*
N11	0.5017 (9)	0.3505 (18)	0.3017 (15)	0.0108 (3)*
N12	0.9011 (8)	0.9851 (10)	0.2255 (8)	0.0108 (3)*
N13	0.7984 (7)	0.8789 (13)	0.9806 (12)	0.0108 (3)*
N14	0.5986 (8)	1.1229 (10)	0.4854 (8)	0.0108 (3)*
N15	1.0006 (7)	0.8822 (13)	0.9770 (12)	0.0108 (3)*
N16	0.7037 (7)	1.0287 (13)	0.7367 (11)	0.0108 (3)*
N17	0.8937 (9)	0.3424 (17)	0.2743 (14)	0.0198 (8)*	0.50
O17	0.8937 (9)	0.3424 (17)	0.2743 (14)	0.0198 (8)*	0.50
N18	0.6009 (8)	0.6407 (13)	0.2163 (12)	0.0198 (8)*	0.50
O18	0.6009 (8)	0.6407 (13)	0.2163 (12)	0.0198 (8)*	0.50
N19	0.6054 (9)	0.3427 (16)	0.7602 (14)	0.0198 (8)*	0.50
O19	0.6054 (9)	0.3427 (16)	0.7602 (14)	0.0198 (8)*	0.50
N20	0.8832 (7)	0.6333 (16)	0.8160 (15)	0.0198 (8)*	0.50
O20	0.8832 (7)	0.6333 (16)	0.8160 (15)	0.0198 (8)*	0.50
N21	0.9172 (10)	0.5896 (13)	0.5118 (15)	0.0170 (7)*
N22	0.5862 (11)	0.5887 (12)	0.5222 (15)	0.0170 (7)*
N23	0.7617 (8)	0.4054 (11)	1.0138 (16)	0.0170 (7)*

	U11	U22	U33	U12	U13	U23
Sr1	0.0449 (6)	0.0107 (4)	0.0270 (6)	−0.0073 (12)	0.0216 (5)	−0.0071 (9)
Sr2	0.0732 (18)	0.0225 (7)	0.0126 (7)	−0.0157 (15)	0.0099 (9)	−0.0044 (5)
Eu2	0.0732 (18)	0.0225 (7)	0.0126 (7)	−0.0157 (15)	0.0099 (9)	−0.0044 (5)
Sr3	0.0664 (17)	0.0363 (11)	0.0143 (8)	0.0289 (14)	0.0104 (9)	−0.0003 (6)
Eu3	0.0664 (17)	0.0363 (11)	0.0143 (8)	0.0289 (14)	0.0104 (9)	−0.0003 (6)

Sr1—N9	2.618 (13)	Si7—N7	1.764 (11)
Sr1—N8	2.682 (13)	Si7—N14	1.769 (11)
Sr1—N22	2.690 (16)	Si8—O18iv	1.703 (10)
Sr1—N21	2.745 (14)	Si8—N3iv	1.789 (11)
Sr1—N7	2.773 (9)	Si8—N2	1.789 (8)
Sr1—N16	2.955 (10)	Si8—N1	1.792 (11)
Sr1—N3	3.032 (10)	Si9—O17i	1.725 (13)
Sr2—N23i	2.557 (11)	Si9—N12	1.749 (8)
Sr2—O17ii	2.573 (13)	Si9—N7	1.784 (11)
Sr2—N21iii	2.702 (14)	Si9—N15xii	1.795 (11)
Sr2—N4i	2.764 (14)	Si10—O20	1.696 (13)
Sr2—N12iv	2.868 (7)	Si10—N15	1.775 (11)
Sr2—N10	2.970 (8)	Si10—N10	1.786 (8)
Sr2—N15	3.052 (10)	Si10—N13	1.792 (11)
Sr3—O19i	2.549 (12)	Al11—N21	1.687 (13)
Sr3—N22v	2.718 (16)	Al11—O20	1.710 (14)
Sr3—N2	2.760 (7)	Al11—N5viii	1.771 (12)
Sr3—N11ii	2.783 (13)	Al11—N4	1.819 (14)
Sr3—N23i	2.851 (11)	Al12—N4vi	1.685 (15)
Sr3—N6iv	2.994 (13)	Al12—O17	1.690 (13)
Sr3—N1	3.096 (10)	Al12—N21	1.702 (14)
Si1—N15vi	1.732 (12)	Al12—N8	1.829 (14)
Si1—N12vii	1.755 (12)	Al13—O18	1.672 (11)
Si1—N4	1.765 (14)	Al13—N22	1.711 (13)
Si1—N10viii	1.769 (11)	Al13—N11	1.740 (14)
Si2—N16	1.734 (11)	Al13—N6viii	1.773 (14)
Si2—N5	1.742 (13)	Al14—N22	1.671 (14)
Si2—N7	1.750 (12)	Al14—O19	1.678 (12)
Si2—N10	1.787 (11)	Al14—N9	1.747 (14)
Si3—N1ix	1.734 (11)	Al14—N11x	1.791 (15)
Si3—N11x	1.741 (15)	Al15—N23	1.697 (15)
Si3—N14v	1.752 (11)	Al15—N5viii	1.730 (14)
Si3—N2	1.770 (11)	Al15—N9	1.807 (16)
Si4—N14	1.743 (8)	Al15—O20	1.811 (13)
Si4—O19i	1.749 (13)	Al16—N9	1.700 (15)
Si4—N1ix	1.788 (12)	Al16—N5viii	1.811 (14)
Si4—N16	1.789 (12)	Al16—N23	1.820 (15)
Si5—N13	1.745 (11)	Al16—O19	1.906 (15)
Si5—N2	1.762 (11)	Al17—N8	1.687 (16)
Si5—N16	1.770 (11)	Al17—N23xi	1.694 (16)
Si5—N9	1.802 (14)	Al17—N6viii	1.762 (15)
Si6—N13xi	1.742 (12)	Al17—O17	2.026 (15)
Si6—N12	1.752 (12)	Al18—N6viii	1.716 (16)
Si6—N8	1.768 (15)	Al18—N8	1.745 (16)
Si6—N3	1.777 (11)	Al18—N23xi	1.783 (15)
Si7—N6	1.728 (15)	Al18—O18	2.072 (14)
Si7—N3	1.756 (11)
N15vi—Si1—N12vii	106.4 (5)	O20—Si10—N15	115.0 (5)
N15vi—Si1—N4	112.0 (6)	O20—Si10—N10	117.7 (6)
N12vii—Si1—N4	108.2 (6)	N15—Si10—N10	104.5 (5)
N15vi—Si1—N10viii	110.2 (5)	O20—Si10—N13	100.0 (6)
N12vii—Si1—N10viii	113.0 (4)	N15—Si10—N13	113.6 (4)
N4—Si1—N10viii	107.1 (6)	N10—Si10—N13	106.0 (5)
N16—Si2—N5	114.3 (6)	N21—Al11—O20	111.8 (6)
N16—Si2—N7	105.9 (5)	N21—Al11—N5viii	118.4 (6)
N5—Si2—N7	109.5 (5)	O20—Al11—N5viii	91.8 (6)
N16—Si2—N10	110.7 (5)	N21—Al11—N4	118.3 (7)
N5—Si2—N10	108.8 (5)	O20—Al11—N4	108.3 (6)
N7—Si2—N10	107.3 (5)	N5viii—Al11—N4	104.8 (6)
N1ix—Si3—N11x	110.2 (6)	N4vi—Al12—O17	113.7 (7)
N1ix—Si3—N14v	110.2 (5)	N4vi—Al12—N21	111.3 (7)
N11x—Si3—N14v	105.0 (6)	O17—Al12—N21	114.4 (6)
N1ix—Si3—N2	106.4 (5)	N4vi—Al12—N8	106.8 (6)
N11x—Si3—N2	112.0 (6)	O17—Al12—N8	98.1 (7)
N14v—Si3—N2	113.1 (4)	N21—Al12—N8	111.7 (6)
N14—Si4—O19i	117.0 (5)	O18—Al13—N22	111.7 (5)
N14—Si4—N1ix	106.6 (5)	O18—Al13—N11	106.0 (6)
O19i—Si4—N1ix	108.0 (6)	N22—Al13—N11	117.3 (7)
N14—Si4—N16	107.0 (5)	O18—Al13—N6viii	97.8 (7)
O19i—Si4—N16	102.8 (6)	N22—Al13—N6viii	119.2 (7)
N1ix—Si4—N16	115.9 (4)	N11—Al13—N6viii	102.4 (5)
N13—Si5—N2	113.3 (5)	N22—Al14—O19	116.1 (6)
N13—Si5—N16	107.7 (5)	N22—Al14—N9	111.7 (7)
N2—Si5—N16	107.7 (5)	O19—Al14—N9	101.0 (7)
N13—Si5—N9	112.2 (6)	N22—Al14—N11x	112.3 (7)
N2—Si5—N9	110.4 (6)	O19—Al14—N11x	108.0 (7)
N16—Si5—N9	105.0 (5)	N9—Al14—N11x	106.9 (6)
N13xi—Si6—N12	106.4 (5)	N23—Al15—N5viii	111.2 (7)
N13xi—Si6—N8	114.0 (6)	N23—Al15—N9	117.9 (7)
N12—Si6—N8	107.5 (6)	N5viii—Al15—N9	108.8 (7)
N13xi—Si6—N3	109.9 (5)	N23—Al15—O20	120.7 (7)
N12—Si6—N3	113.3 (5)	N5viii—Al15—O20	89.8 (7)
N8—Si6—N3	106.0 (6)	N9—Al15—O20	104.8 (7)
N6—Si7—N3	115.2 (6)	N9—Al16—N5viii	109.9 (7)
N6—Si7—N7	115.5 (6)	N9—Al16—N23	117.1 (6)
N3—Si7—N7	101.2 (5)	N5viii—Al16—N23	102.3 (6)
N6—Si7—N14	102.3 (5)	N9—Al16—O19	94.1 (6)
N3—Si7—N14	109.1 (4)	N5viii—Al16—O19	109.7 (6)
N7—Si7—N14	113.9 (5)	N23—Al16—O19	123.7 (6)
O18iv—Si8—N3iv	111.7 (6)	N8—Al17—N23xi	117.6 (7)
O18iv—Si8—N2	111.1 (5)	N8—Al17—N6viii	113.5 (8)
N3iv—Si8—N2	107.0 (5)	N23xi—Al17—N6viii	112.7 (7)
O18iv—Si8—N1	112.5 (6)	N8—Al17—O17	91.0 (7)
N3iv—Si8—N1	111.3 (4)	N23xi—Al17—O17	112.1 (7)
N2—Si8—N1	102.8 (5)	N6viii—Al17—O17	107.6 (7)
O17i—Si9—N12	102.2 (5)	N6viii—Al18—N8	112.9 (8)
O17i—Si9—N7	112.5 (6)	N6viii—Al18—N23xi	110.7 (7)
N12—Si9—N7	109.0 (5)	N8—Al18—N23xi	110.1 (7)
O17i—Si9—N15xii	112.8 (6)	N6viii—Al18—O18	86.0 (6)
N12—Si9—N15xii	108.2 (5)	N8—Al18—O18	106.5 (7)
N7—Si9—N15xii	111.6 (4)	N23xi—Al18—O18	128.4 (7)

Table 1

Selected bond lengths (Å)

Sr1—N9	2.618 (13)
Sr1—N8	2.682 (13)
Sr1—N22	2.690 (16)
Sr1—N21	2.745 (14)
Sr1—N7	2.773 (9)
Sr1—N16	2.955 (10)
Sr1—N3	3.032 (10)
Sr2—N23i	2.557 (11)
Sr2—O17ii	2.573 (13)
Sr2—N21iii	2.702 (14)
Sr2—N4i	2.764 (14)
Sr2—N12iv	2.868 (7)
Sr2—N10	2.970 (8)
Sr2—N15	3.052 (10)
Sr3—O19i	2.549 (12)
Sr3—N22v	2.718 (16)
Sr3—N2	2.760 (7)
Sr3—N11ii	2.783 (13)
Sr3—N23i	2.851 (11)
Sr3—N6iv	2.994 (13)
Sr3—N1	3.096 (10)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) .