Strontium nitride carbodiimide, Sr4N2(CN2)

Gál, Z.A.; Mallinson, P.M.; Clarke, S.J.

doi:10.1107/S1600536805030850

inorganic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 61| Part 10| October 2005| Pages i221-i222

doi:10.1107/S1600536805030850

Strontium nitride carbodiimide, Sr₄N₂(CN₂)

Zoltán A. Gál,^a Phillip M. Mallinson ^a ‡ and Simon J. Clarke ^a ^*

^aDepartment of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, England
^*Correspondence e-mail: simon.clarke@chem.ox.ac.uk

(Received 19 September 2005; accepted 27 September 2005; online 30 September 2005)

Strontium nitride carbodiimide, Sr₄N₂(CN₂), is isostructural with the calcium analogue and consists of a framework of edge- and vertex-sharing Sr₆N octahedra forming channels within which almost linear and almost symmetrical carbodiimide anions reside, surrounded by eight strontium ions.

Comment

There is increasing interest in the chemistry of the nitrides of the elements and one way to grow crystals of alkaline earth main group nitrides is to make use of a molten sodium flux (Yamane & DiSalvo, 1996 ; Reckeweg & DiSalvo, 2000 ). In attempting to grow crystals of strontium aluminium nitrides we grew crystals of the title phase. Strontium nitride carbodiimide is isostructural with the calcium analogue Ca₄N₂(CN₂) (Reckeweg & DiSalvo, 2000) and with Ca_3.2Sr_0.8N₂(CN₂) (Höhn et al., 2000 ). The structure consists of a three-dimensional framework of Sr₆N octahedra, centred by atoms N3 and N4, linked by their edges and vertices. Channels are formed which accommodate the carbodiimide anions. Each N atom of the carbodiimide anion is within 3.0 Å of four strontium ions and the [CN₂]²⁻ anions should be considered eight-coordinate by strontium cations. Atoms Sr1 and Sr3 are coordinated by five N atoms within 3 Å, Sr2 is in approximately octahedral coordination by six N atoms, and Sr4 is in distorted tetrahedral coordination by four N atoms within 2.7 Å, with a fifth N atom 3.228 (4) Å distant. The carbodiimide anions are almost linear, with an N—C—N bond angle of 178.0 (5)°, and the anion is in the symmetrical carbodiimide form, with C—N bond lengths of 1.240 (6) and 1.235 (6) Å, which are equal within experimental uncertainty. The geometry of the carbodiimide anions in Ca₄N₂(CN₂) is similar: C—N bond lengths of 1.22 (1) and 1.24 (1) Å, and an N—C—N angle of 179.7 (10)° (Reckeweg & DiSalvo, 2000). The structure of Sr₄N₂(CN₂) is shown in Fig. 1.

Figure 1
The structure of Sr₄N₂(CN₂), showing the framework of Sr₆N octahedra and the channels containing the carbodiimide anions. The detail shows the asymmetric unit, with 99% displacement ellipsoids.

Experimental

Strontium nitride carbodiimide was synthesized by reacting together Sr (99%, Aldrich, 100 mg), NaN₃ (99%, Aldrich, 85 mg), Al (99.99%, Aldrich, 31 mg) and Na (99+ %, BDH, 200 mg) in a sealed nickel tube at 1073 K for 4 d, with slow cooling to 673 K prior to removal of the tube from the furnace. A small number of colourless crystals of the product were obtained after sublimation of excess sodium from the reactants. No other crystalline products were identified in the reaction. The carbon forming the carbodiimide units presumably arises adventitiously from the nickel tube or from one or more of the reactants, as noted by Reckeweg & DiSalvo (2000).

Crystal data

Sr₄N₂(CN₂)
M_r = 418.53
Orthorhombic, P n m a
a = 12.2928 (4) Å
b = 3.8261 (1) Å
c = 14.3291 (5) Å
V = 673.95 (4) Å³
Z = 4
D_x = 4.125 Mg m⁻³
Mo Kα radiation
Cell parameters from 43855 reflections
θ = 1.0–33.1°
μ = 31.39 mm⁻¹
T = 150 (2) K
Prism, colourless above
0.09 × 0.05 × 0.02 mm

Data collection

Nonius KappaCCD diffractometer
ω scans
Absorption correction: analytical(Alcock, 1970 )T_min = 0.062, T_max = 0.301
14693 measured reflections
1156 independent reflections
942 reflections with I > 2σ(I)
R_int = 0.076
θ_max = 30.5°
h = −17 → 17
k = −5 → 5
l = −20 → 20

Refinement

Refinement on F²
R[F² > 2σ(F²)] = 0.026
wR(F²) = 0.050
S = 1.07
1156 reflections
56 parameters
w = 1/[σ²(F_o²) + (0.0142P)² + 1.6092P] where P = (F_o² + 2F_c²)/3
(Δ/σ)_max = 0.001
Δρ_max = 1.12 e Å⁻³
Δρ_min = −0.99 e Å⁻³
Extinction correction: SHELXL97
Extinction coefficient: 0.00093 (15)

Table 1
Selected geometric parameters (Å, °)

Sr1—N3ⁱ	2.551 (3)
Sr1—N3ⁱⁱ	2.551 (3)
Sr1—N2	2.799 (4)
Sr1—N1ⁱⁱⁱ	2.837 (3)
Sr1—N1^iv	2.837 (3)
Sr2—N4^v	2.674 (3)
Sr2—N4^vi	2.674 (3)
Sr2—N3	2.740 (4)
Sr2—N4^vii	2.774 (4)
Sr2—N2^vi	2.867 (3)
Sr2—N2^v	2.867 (3)
Sr3—N4	2.490 (4)
Sr3—N3ⁱⁱ	2.616 (3)
Sr3—N3ⁱ	2.616 (3)
Sr3—N1ⁱ	2.998 (3)
Sr3—N1ⁱⁱ	2.998 (3)
Sr4—N4^viii	2.500 (2)
Sr4—N4^ix	2.500 (2)
Sr4—N3	2.592 (4)
Sr4—N2	2.683 (4)
N1—C5	1.240 (6)
N2—C5	1.235 (6)

N2—C5—N1

178.0 (5)

Symmetry codes: (i) $[-x+{\script{1\over 2}}, -y+1, z+{\script{1\over 2}}]$ ; (ii) $[-x+{\script{1\over 2}}, -y, z+{\script{1\over 2}}]$ ; (iii) -x, -y, -z+1; (iv) -x, -y+1, -z+1; (v) $[-x+{\script{1\over 2}}, -y, z-{\script{1\over 2}}]$ ; (vi) $[-x+{\script{1\over 2}}, -y+1, z-{\script{1\over 2}}]$ ; (vii) $[x-{\script{1\over 2}}, y, -z+{\script{1\over 2}}]$ ; (viii) -x+1, -y+1, -z+1; (ix) -x+1, -y, -z+1.

The highest residdual electron-density peak is located 1.57 Å from atom Sr3. [1.12 e Å⁻³].

Data collection: COLLECT (Nonius, 2000 ); cell refinement: SCALEPACK (Otwinowski & Minor, 1997 ); data reduction: SCALEPACK and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELX97 (Sheldrick, 1997 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ATOMS (Dowty, 2005 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536805030850/br6219sup1.cif

Structure factors: contains datablock new. DOI: 10.1107/S1600536805030850/br6219Isup2.hkl

Comment top

There is increasing interest in the chemistry of the nitrides of the elements and one way to grow crystals of alkaline earth main group nitrides is to make use of a molten sodium flux (Yamane & DiSalvo, 1996; Reckeweg & DiSalvo, 2000). In attempting to grow crystals of strontium aluminium nitrides we grew crystals of the title phase. Strontium nitride carbodiimide is isostructural with the calcium analogue Ca₄N₂(CN₂) (Reckeweg & DiSalvo, 2000) and with Ca_3.2Sr_0.8N₂(CN₂) (Höhn et al., 2000). The structure consists of a three-dimensional framework of Sr₆N octahedra, centred by atoms N3 and N4, linked by their edges and vertices. Channels are formed which accommodate the carbodiimide anions. Each N atom of the carbodiimide anion is within 3.0 Å of four strontium ions and the [CN₂]²⁻ anions should be considered eight-coordinate by strontium cations. Atoms Sr1 and Sr3 are coordinated by five N atoms within 3 Å, Sr2 is in approximately octahedral coordination by six N atoms, and Sr4 is in distorted tetrahedral coordination by four N atoms within 2.7 Å, with a fifth N atom 3.228 (4) Å distant. The carbodiimide anions are almost linear, with an N—C—N bond angle of 178.0 (5)°, and the anion is in the symmetrical carbodiimide form, with C—N bond lengths of 1.240 (6) and 1.235 (6) Å, which are equal within experimental uncertainty. The geometry of the carbodiimide anions in Ca₄N₂(CN₂) is similar: C—N bond lengths of 1.22 (1) and 1.24 (1) Å, and an N—C—N angle of 179.7 (10)° (Reckeweg & DiSalvo, 2000). The structure of Sr₄N₂(CN₂) is shown in Fig. 1.

Experimental top

Strontium nitride carbodiimide was synthesized by reacting together Sr (99%, Aldrich, 100 mg), NaN₃ (99%, Aldrich, 85 mg), Al (99.99%, Aldrich, 31 mg) and Na (99+ %, BDH, 200 mg) in a sealed nickel tube at 1073 K for 4 d, with slow cooling to 673 K prior to removal of the tube from the furnace. A small numbers of colourless crystals of the product were obtained after sublimation of excess sodium from the reactants. No other crystalline products were identified in the reaction. The carbon forming the carbodiimide units presumably arises adventitiously from the nickel tube or from one or more of the reactants, as noted by Reckeweg & DiSalvo (2000).

Computing details top

Data collection: COLLECT (Nonius, 2000); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: SCALEPACK and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELX97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ATOMS (Dowty, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

Fig. 1. The structure of Sr₄N₂(CN₂), showing the framework of Sr₆N octahedra and the channels containing the carbodiimide anions. The detail shows the asymmetric unit depicting 99% displacement ellipsoids.

Strontium nitride carbodiimide top

Crystal data top

Sr₄N₂(CN₂)	F(000) = 744
M_r = 418.53	D_x = 4.125 Mg m⁻³
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 43855 reflections
a = 12.2928 (4) Å	θ = 1.0–33.1°
b = 3.8261 (1) Å	µ = 31.39 mm⁻¹
c = 14.3291 (5) Å	T = 150 K
V = 673.95 (4) Å³	Prism, white
Z = 4	0.09 × 0.05 × 0.02 mm

Data collection top

Nonius KappaCCD diffractometer	1156 independent reflections
Radiation source: Enraf Nonius FR590	942 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.076
CCD rotation images, thick slices scans	θ_max = 30.5°, θ_min = 5.2°
Absorption correction: analytical (Alcock, 1970)	h = −17→17
T_min = 0.062, T_max = 0.301	k = −5→5
14693 measured reflections	l = −20→20

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)] = 0.026	w = 1/[σ²(F_o²) + (0.0142P)² + 1.6092P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.050	(Δ/σ)_max = 0.001
S = 1.07	Δρ_max = 1.12 e Å⁻³
1156 reflections	Δρ_min = −0.99 e Å⁻³
56 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.00093 (15)

Crystal data top

Sr₄N₂(CN₂)	V = 673.95 (4) Å³
M_r = 418.53	Z = 4
Orthorhombic, Pnma	Mo Kα radiation
a = 12.2928 (4) Å	µ = 31.39 mm⁻¹
b = 3.8261 (1) Å	T = 150 K
c = 14.3291 (5) Å	0.09 × 0.05 × 0.02 mm

Data collection top

Nonius KappaCCD diffractometer	1156 independent reflections
Absorption correction: analytical (Alcock, 1970)	942 reflections with I > 2σ(I)
T_min = 0.062, T_max = 0.301	R_int = 0.076
14693 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.026	56 parameters
wR(F²) = 0.050	0 restraints
S = 1.07	Δρ_max = 1.12 e Å⁻³
1156 reflections	Δρ_min = −0.99 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
Sr1	0.11185 (3)	0.25	0.59628 (3)	0.00995 (11)
Sr2	0.12505 (3)	0.25	0.03205 (3)	0.00994 (11)
Sr3	0.33905 (3)	0.25	0.73997 (3)	0.00994 (11)
Sr4	0.40728 (3)	0.25	0.31366 (3)	0.01062 (11)
N1	0.0547 (3)	0.25	0.3728 (3)	0.0178 (9)
N2	0.2420 (3)	0.25	0.4360 (3)	0.0164 (9)
N3	0.2803 (3)	0.25	0.1692 (3)	0.0115 (8)
N4	0.4864 (3)	0.25	0.6207 (3)	0.0115 (8)
C5	0.1492 (4)	0.25	0.4031 (4)	0.0144 (9)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Sr1	0.0104 (2)	0.00829 (19)	0.0111 (2)	0	−0.00008 (16)	0
Sr2	0.0105 (2)	0.00805 (19)	0.0112 (2)	0	0.00027 (16)	0
Sr3	0.0103 (2)	0.00786 (18)	0.0117 (2)	0	−0.00007 (16)	0
Sr4	0.0118 (2)	0.00723 (19)	0.0128 (2)	0	−0.00272 (17)	0
N1	0.0107 (19)	0.0163 (19)	0.026 (2)	0	0.0005 (18)	0
N2	0.014 (2)	0.0161 (19)	0.019 (2)	0	0.0015 (17)	0
N3	0.0130 (19)	0.0081 (17)	0.014 (2)	0	−0.0004 (16)	0
N4	0.0109 (18)	0.0096 (17)	0.014 (2)	0	0.0006 (15)	0
C5	0.020 (2)	0.0086 (19)	0.015 (2)	0	0.005 (2)	0

Geometric parameters (Å, º) top

Sr1—N3ⁱ	2.551 (3)	Sr3—Sr4ⁱ	3.7341 (5)
Sr1—N3ⁱⁱ	2.551 (3)	Sr4—N4^xi	2.500 (2)
Sr1—N2	2.799 (4)	Sr4—N4^xii	2.500 (2)
Sr1—C5	2.807 (5)	Sr4—N3	2.592 (4)
Sr1—N1ⁱⁱⁱ	2.837 (3)	Sr4—N2	2.683 (4)
Sr1—N1^iv	2.837 (3)	Sr4—N1^xiii	3.228 (4)
Sr1—N1	3.279 (5)	Sr4—Sr2^xiii	3.4720 (6)
Sr1—Sr3	3.4699 (6)	Sr4—Sr1^vii	3.6629 (5)
Sr1—Sr4ⁱ	3.6629 (5)	Sr4—Sr1^viii	3.6629 (5)
Sr1—Sr4ⁱⁱ	3.6629 (5)	Sr4—Sr2ⁱ	3.6893 (5)
Sr1—Sr1^v	3.8261 (1)	Sr4—Sr2ⁱⁱ	3.6893 (5)
Sr1—Sr1^vi	3.8261 (1)	Sr4—Sr3^vii	3.7341 (5)
Sr2—N4^vii	2.674 (3)	Sr4—Sr3^viii	3.7341 (5)
Sr2—N4^viii	2.674 (3)	N1—C5	1.240 (6)
Sr2—N3	2.740 (4)	N1—Sr1ⁱⁱⁱ	2.837 (3)
Sr2—N4^ix	2.774 (4)	N1—Sr1^iv	2.837 (3)
Sr2—N2^viii	2.867 (3)	N1—Sr3^vii	2.998 (3)
Sr2—N2^vii	2.867 (3)	N1—Sr3^viii	2.998 (3)
Sr2—Sr4^ix	3.4720 (6)	N1—Sr4^ix	3.228 (4)
Sr2—Sr3^viii	3.5680 (5)	N2—C5	1.235 (6)
Sr2—Sr3^vii	3.5680 (5)	N2—Sr2ⁱ	2.867 (3)
Sr2—Sr4^vii	3.6893 (5)	N2—Sr2ⁱⁱ	2.867 (3)
Sr2—Sr4^viii	3.6893 (5)	N3—Sr1^viii	2.551 (3)
Sr2—Sr2^x	3.7358 (7)	N3—Sr1^vii	2.551 (3)
Sr3—N4	2.490 (4)	N3—Sr3^vii	2.616 (3)
Sr3—N3ⁱⁱ	2.616 (3)	N3—Sr3^viii	2.616 (3)
Sr3—N3ⁱ	2.616 (3)	N4—Sr4^xi	2.500 (2)
Sr3—N1ⁱ	2.998 (3)	N4—Sr4^xii	2.500 (2)
Sr3—N1ⁱⁱ	2.998 (3)	N4—Sr2ⁱⁱ	2.674 (3)
Sr3—C5ⁱ	3.024 (4)	N4—Sr2ⁱ	2.674 (3)
Sr3—C5ⁱⁱ	3.024 (4)	N4—Sr2^xiii	2.774 (4)
Sr3—Sr2ⁱⁱ	3.5680 (5)	C5—Sr3^vii	3.024 (4)
Sr3—Sr2ⁱ	3.5680 (5)	C5—Sr3^viii	3.024 (4)
Sr3—Sr4ⁱⁱ	3.7341 (5)

N3ⁱ—Sr1—N3ⁱⁱ	97.16 (13)	N4—Sr3—Sr2ⁱ	48.48 (6)
N3ⁱ—Sr1—N2	92.24 (10)	N3ⁱⁱ—Sr3—Sr2ⁱ	97.93 (8)
N3ⁱⁱ—Sr1—N2	92.24 (10)	N3ⁱ—Sr3—Sr2ⁱ	49.73 (9)
N3ⁱ—Sr1—C5	108.62 (11)	N1ⁱ—Sr3—Sr2ⁱ	97.70 (7)
N3ⁱⁱ—Sr1—C5	108.62 (11)	N1ⁱⁱ—Sr3—Sr2ⁱ	144.92 (8)
N2—Sr1—C5	25.46 (13)	C5ⁱ—Sr3—Sr2ⁱ	107.47 (6)
N3ⁱ—Sr1—N1ⁱⁱⁱ	144.73 (12)	C5ⁱⁱ—Sr3—Sr2ⁱ	168.16 (9)
N3ⁱⁱ—Sr1—N1ⁱⁱⁱ	78.77 (10)	Sr1—Sr3—Sr2ⁱ	66.676 (11)
N2—Sr1—N1ⁱⁱⁱ	122.75 (10)	Sr2ⁱⁱ—Sr3—Sr2ⁱ	64.846 (11)
C5—Sr1—N1ⁱⁱⁱ	105.80 (11)	N4—Sr3—Sr4ⁱⁱ	141.62 (5)
N3ⁱ—Sr1—N1^iv	78.77 (10)	N3ⁱⁱ—Sr3—Sr4ⁱⁱ	43.93 (9)
N3ⁱⁱ—Sr1—N1^iv	144.73 (12)	N3ⁱ—Sr3—Sr4ⁱⁱ	91.68 (8)
N2—Sr1—N1^iv	122.75 (10)	N1ⁱ—Sr3—Sr4ⁱⁱ	120.05 (8)
C5—Sr1—N1^iv	105.80 (11)	N1ⁱⁱ—Sr3—Sr4ⁱⁱ	81.19 (7)
N1ⁱⁱⁱ—Sr1—N1^iv	84.80 (11)	C5ⁱ—Sr3—Sr4ⁱⁱ	98.30 (9)
N3ⁱ—Sr1—N1	120.76 (9)	C5ⁱⁱ—Sr3—Sr4ⁱⁱ	59.74 (9)
N3ⁱⁱ—Sr1—N1	120.76 (9)	Sr1—Sr3—Sr4ⁱⁱ	60.992 (11)
N2—Sr1—N1	47.24 (11)	Sr2ⁱⁱ—Sr3—Sr4ⁱⁱ	93.538 (10)
C5—Sr1—N1	21.78 (12)	Sr2ⁱ—Sr3—Sr4ⁱⁱ	127.667 (15)
N1ⁱⁱⁱ—Sr1—N1	89.89 (11)	N4—Sr3—Sr4ⁱ	141.62 (5)
N1^iv—Sr1—N1	89.89 (11)	N3ⁱⁱ—Sr3—Sr4ⁱ	91.68 (8)
N3ⁱ—Sr1—Sr3	48.61 (7)	N3ⁱ—Sr3—Sr4ⁱ	43.93 (9)
N3ⁱⁱ—Sr1—Sr3	48.61 (7)	N1ⁱ—Sr3—Sr4ⁱ	81.19 (7)
N2—Sr1—Sr3	91.52 (9)	N1ⁱⁱ—Sr3—Sr4ⁱ	120.05 (8)
C5—Sr1—Sr3	116.98 (10)	C5ⁱ—Sr3—Sr4ⁱ	59.74 (9)
N1ⁱⁱⁱ—Sr1—Sr3	119.22 (8)	C5ⁱⁱ—Sr3—Sr4ⁱ	98.30 (9)
N1^iv—Sr1—Sr3	119.22 (8)	Sr1—Sr3—Sr4ⁱ	60.992 (11)
N1—Sr1—Sr3	138.77 (7)	Sr2ⁱⁱ—Sr3—Sr4ⁱ	127.667 (15)
N3ⁱ—Sr1—Sr4ⁱ	45.03 (9)	Sr2ⁱ—Sr3—Sr4ⁱ	93.538 (10)
N3ⁱⁱ—Sr1—Sr4ⁱ	94.39 (8)	Sr4ⁱⁱ—Sr3—Sr4ⁱ	61.636 (9)
N2—Sr1—Sr4ⁱ	137.25 (6)	N4^xi—Sr4—N4^xii	99.84 (13)
C5—Sr1—Sr4ⁱ	148.147 (16)	N4^xi—Sr4—N3	127.95 (7)
N1ⁱⁱⁱ—Sr1—Sr4ⁱ	99.96 (8)	N4^xii—Sr4—N3	127.95 (7)
N1^iv—Sr1—Sr4ⁱ	57.90 (9)	N4^xi—Sr4—N2	98.62 (11)
N1—Sr1—Sr4ⁱ	144.77 (3)	N4^xii—Sr4—N2	98.62 (11)
Sr3—Sr1—Sr4ⁱ	63.069 (11)	N3—Sr4—N2	93.79 (12)
N3ⁱ—Sr1—Sr4ⁱⁱ	94.39 (8)	N4^xi—Sr4—N1^xiii	91.02 (10)
N3ⁱⁱ—Sr1—Sr4ⁱⁱ	45.03 (9)	N4^xii—Sr4—N1^xiii	91.02 (10)
N2—Sr1—Sr4ⁱⁱ	137.25 (6)	N3—Sr4—N1^xiii	71.17 (12)
C5—Sr1—Sr4ⁱⁱ	148.147 (16)	N2—Sr4—N1^xiii	164.96 (12)
N1ⁱⁱⁱ—Sr1—Sr4ⁱⁱ	57.90 (9)	N4^xi—Sr4—Sr2^xiii	50.03 (7)
N1^iv—Sr1—Sr4ⁱⁱ	99.96 (8)	N4^xii—Sr4—Sr2^xiii	50.03 (7)
N1—Sr1—Sr4ⁱⁱ	144.77 (3)	N3—Sr4—Sr2^xiii	166.57 (9)
Sr3—Sr1—Sr4ⁱⁱ	63.069 (11)	N2—Sr4—Sr2^xiii	99.65 (9)
Sr4ⁱ—Sr1—Sr4ⁱⁱ	62.969 (10)	N1^xiii—Sr4—Sr2^xiii	95.39 (8)
N3ⁱ—Sr1—Sr1^v	41.42 (7)	N4^xi—Sr4—Sr1^vii	138.85 (9)
N3ⁱⁱ—Sr1—Sr1^v	138.58 (7)	N4^xii—Sr4—Sr1^vii	87.35 (8)
N2—Sr1—Sr1^v	90	N3—Sr4—Sr1^vii	44.14 (6)
C5—Sr1—Sr1^v	90	N2—Sr4—Sr1^vii	120.47 (7)
N1ⁱⁱⁱ—Sr1—Sr1^v	132.40 (6)	N1^xiii—Sr4—Sr1^vii	48.12 (5)
N1^iv—Sr1—Sr1^v	47.60 (6)	Sr2^xiii—Sr4—Sr1^vii	126.227 (13)
N1—Sr1—Sr1^v	90	N4^xi—Sr4—Sr1^viii	87.35 (8)
Sr3—Sr1—Sr1^v	90	N4^xii—Sr4—Sr1^viii	138.85 (9)
Sr4ⁱ—Sr1—Sr1^v	58.515 (5)	N3—Sr4—Sr1^viii	44.14 (6)
Sr4ⁱⁱ—Sr1—Sr1^v	121.485 (5)	N2—Sr4—Sr1^viii	120.47 (7)
N3ⁱ—Sr1—Sr1^vi	138.58 (7)	N1^xiii—Sr4—Sr1^viii	48.12 (5)
N3ⁱⁱ—Sr1—Sr1^vi	41.42 (7)	Sr2^xiii—Sr4—Sr1^viii	126.227 (13)
N2—Sr1—Sr1^vi	90	Sr1^vii—Sr4—Sr1^viii	62.970 (10)
C5—Sr1—Sr1^vi	90	N4^xi—Sr4—Sr2ⁱ	48.74 (9)
N1ⁱⁱⁱ—Sr1—Sr1^vi	47.60 (6)	N4^xii—Sr4—Sr2ⁱ	97.70 (8)
N1^iv—Sr1—Sr1^vi	132.40 (6)	N3—Sr4—Sr2ⁱ	127.77 (7)
N1—Sr1—Sr1^vi	90	N2—Sr4—Sr2ⁱ	50.52 (7)
Sr3—Sr1—Sr1^vi	90	N1^xiii—Sr4—Sr2ⁱ	139.68 (5)
Sr4ⁱ—Sr1—Sr1^vi	121.485 (5)	Sr2^xiii—Sr4—Sr2ⁱ	62.802 (12)
Sr4ⁱⁱ—Sr1—Sr1^vi	58.515 (5)	Sr1^vii—Sr4—Sr2ⁱ	170.134 (16)
Sr1^v—Sr1—Sr1^vi	180.00 (2)	Sr1^viii—Sr4—Sr2ⁱ	116.332 (6)
N4^vii—Sr2—N4^viii	91.34 (12)	N4^xi—Sr4—Sr2ⁱⁱ	97.70 (8)
N4^vii—Sr2—N3	90.93 (10)	N4^xii—Sr4—Sr2ⁱⁱ	48.74 (9)
N4^viii—Sr2—N3	90.93 (10)	N3—Sr4—Sr2ⁱⁱ	127.77 (7)
N4^vii—Sr2—N4^ix	93.45 (10)	N2—Sr4—Sr2ⁱⁱ	50.52 (7)
N4^viii—Sr2—N4^ix	93.45 (10)	N1^xiii—Sr4—Sr2ⁱⁱ	139.68 (5)
N3—Sr2—N4^ix	173.73 (11)	Sr2^xiii—Sr4—Sr2ⁱⁱ	62.802 (12)
N4^vii—Sr2—N2^viii	175.70 (9)	Sr1^vii—Sr4—Sr2ⁱⁱ	116.332 (6)
N4^viii—Sr2—N2^viii	92.45 (8)	Sr1^viii—Sr4—Sr2ⁱⁱ	170.134 (16)
N3—Sr2—N2^viii	86.98 (10)	Sr2ⁱ—Sr4—Sr2ⁱⁱ	62.469 (10)
N4^ix—Sr2—N2^viii	88.36 (10)	N4^xi—Sr4—Sr3^vii	157.24 (8)
N4^vii—Sr2—N2^vii	92.45 (8)	N4^xii—Sr4—Sr3^vii	97.94 (7)
N4^viii—Sr2—N2^vii	175.70 (9)	N3—Sr4—Sr3^vii	44.44 (6)
N3—Sr2—N2^vii	86.98 (10)	N2—Sr4—Sr3^vii	64.59 (7)
N4^ix—Sr2—N2^vii	88.36 (10)	N1^xiii—Sr4—Sr3^vii	102.79 (7)
N2^viii—Sr2—N2^vii	83.70 (11)	Sr2^xiii—Sr4—Sr3^vii	143.640 (9)
N4^vii—Sr2—Sr4^ix	45.76 (6)	Sr1^vii—Sr4—Sr3^vii	55.940 (10)
N4^viii—Sr2—Sr4^ix	45.76 (6)	Sr1^viii—Sr4—Sr3^vii	88.571 (12)
N3—Sr2—Sr4^ix	94.61 (8)	Sr2ⁱ—Sr4—Sr3^vii	114.717 (14)
N4^ix—Sr2—Sr4^ix	91.65 (8)	Sr2ⁱⁱ—Sr4—Sr3^vii	83.502 (11)
N2^viii—Sr2—Sr4^ix	138.15 (6)	N4^xi—Sr4—Sr3^viii	97.94 (7)
N2^vii—Sr2—Sr4^ix	138.15 (6)	N4^xii—Sr4—Sr3^viii	157.24 (8)
N4^vii—Sr2—Sr3^viii	92.88 (7)	N3—Sr4—Sr3^viii	44.44 (6)
N4^viii—Sr2—Sr3^viii	44.21 (8)	N2—Sr4—Sr3^viii	64.59 (7)
N3—Sr2—Sr3^viii	46.75 (6)	N1^xiii—Sr4—Sr3^viii	102.79 (7)
N4^ix—Sr2—Sr3^viii	137.30 (5)	Sr2^xiii—Sr4—Sr3^viii	143.640 (9)
N2^viii—Sr2—Sr3^viii	88.43 (7)	Sr1^vii—Sr4—Sr3^viii	88.571 (12)
N2^vii—Sr2—Sr3^viii	133.47 (8)	Sr1^viii—Sr4—Sr3^viii	55.940 (10)
Sr4^ix—Sr2—Sr3^viii	64.129 (11)	Sr2ⁱ—Sr4—Sr3^viii	83.502 (11)
N4^vii—Sr2—Sr3^vii	44.21 (8)	Sr2ⁱⁱ—Sr4—Sr3^viii	114.717 (14)
N4^viii—Sr2—Sr3^vii	92.88 (7)	Sr3^vii—Sr4—Sr3^viii	61.636 (9)
N3—Sr2—Sr3^vii	46.75 (6)	C5—N1—Sr1ⁱⁱⁱ	128.41 (19)
N4^ix—Sr2—Sr3^vii	137.30 (5)	C5—N1—Sr1^iv	128.41 (19)
N2^viii—Sr2—Sr3^vii	133.47 (8)	Sr1ⁱⁱⁱ—N1—Sr1^iv	84.80 (11)
N2^vii—Sr2—Sr3^vii	88.43 (7)	C5—N1—Sr3^vii	79.3 (2)
Sr4^ix—Sr2—Sr3^vii	64.129 (11)	Sr1ⁱⁱⁱ—N1—Sr3^vii	89.04 (5)
Sr3^viii—Sr2—Sr3^vii	64.846 (11)	Sr1^iv—N1—Sr3^vii	147.56 (17)
N4^vii—Sr2—Sr4^vii	88.67 (7)	C5—N1—Sr3^viii	79.3 (2)
N4^viii—Sr2—Sr4^vii	135.95 (8)	Sr1ⁱⁱⁱ—N1—Sr3^viii	147.56 (17)
N3—Sr2—Sr4^vii	133.12 (6)	Sr1^iv—N1—Sr3^viii	89.04 (5)
N4^ix—Sr2—Sr4^vii	42.65 (5)	Sr3^vii—N1—Sr3^viii	79.31 (11)
N2^viii—Sr2—Sr4^vii	90.02 (7)	C5—N1—Sr4^ix	144.7 (4)
N2^vii—Sr2—Sr4^vii	46.24 (8)	Sr1ⁱⁱⁱ—N1—Sr4^ix	73.99 (9)
Sr4^ix—Sr2—Sr4^vii	117.198 (12)	Sr1^iv—N1—Sr4^ix	73.99 (9)
Sr3^viii—Sr2—Sr4^vii	178.441 (13)	Sr3^vii—N1—Sr4^ix	73.70 (9)
Sr3^vii—Sr2—Sr4^vii	116.332 (6)	Sr3^viii—N1—Sr4^ix	73.70 (9)
N4^vii—Sr2—Sr4^viii	135.95 (8)	C5—N1—Sr1	57.1 (3)
N4^viii—Sr2—Sr4^viii	88.67 (7)	Sr1ⁱⁱⁱ—N1—Sr1	90.11 (11)
N3—Sr2—Sr4^viii	133.12 (6)	Sr1^iv—N1—Sr1	90.11 (11)
N4^ix—Sr2—Sr4^viii	42.65 (5)	Sr3^vii—N1—Sr1	121.78 (10)
N2^viii—Sr2—Sr4^viii	46.24 (8)	Sr3^viii—N1—Sr1	121.78 (10)
N2^vii—Sr2—Sr4^viii	90.02 (7)	Sr4^ix—N1—Sr1	158.21 (14)
Sr4^ix—Sr2—Sr4^viii	117.198 (12)	C5—N2—Sr4	116.7 (3)
Sr3^viii—Sr2—Sr4^viii	116.332 (6)	C5—N2—Sr1	77.6 (3)
Sr3^vii—Sr2—Sr4^viii	178.441 (13)	Sr4—N2—Sr1	165.68 (17)
Sr4^vii—Sr2—Sr4^viii	62.469 (10)	C5—N2—Sr2ⁱ	135.23 (12)
N4^vii—Sr2—Sr2^x	47.84 (8)	Sr4—N2—Sr2ⁱ	83.24 (10)
N4^viii—Sr2—Sr2^x	93.52 (7)	Sr1—N2—Sr2ⁱ	86.11 (10)
N3—Sr2—Sr2^x	138.57 (5)	C5—N2—Sr2ⁱⁱ	135.23 (12)
N4^ix—Sr2—Sr2^x	45.61 (6)	Sr4—N2—Sr2ⁱⁱ	83.24 (10)
N2^viii—Sr2—Sr2^x	133.83 (8)	Sr1—N2—Sr2ⁱⁱ	86.11 (10)
N2^vii—Sr2—Sr2^x	90.53 (7)	Sr2ⁱ—N2—Sr2ⁱⁱ	83.70 (11)
Sr4^ix—Sr2—Sr2^x	61.445 (13)	Sr1^viii—N3—Sr1^vii	97.16 (13)
Sr3^viii—Sr2—Sr2^x	125.567 (19)	Sr1^viii—N3—Sr4	90.83 (11)
Sr3^vii—Sr2—Sr2^x	91.864 (12)	Sr1^vii—N3—Sr4	90.83 (11)
Sr4^vii—Sr2—Sr2^x	55.753 (12)	Sr1^viii—N3—Sr3^vii	177.10 (16)
Sr4^viii—Sr2—Sr2^x	88.184 (16)	Sr1^vii—N3—Sr3^vii	84.366 (11)
N4—Sr3—N3ⁱⁱ	98.18 (10)	Sr4—N3—Sr3^vii	91.62 (11)
N4—Sr3—N3ⁱ	98.18 (10)	Sr1^viii—N3—Sr3^viii	84.366 (11)
N3ⁱⁱ—Sr3—N3ⁱ	94.01 (13)	Sr1^vii—N3—Sr3^viii	177.10 (16)
N4—Sr3—N1ⁱ	96.81 (11)	Sr4—N3—Sr3^viii	91.62 (11)
N3ⁱⁱ—Sr3—N1ⁱ	163.18 (11)	Sr3^vii—N3—Sr3^viii	94.01 (13)
N3ⁱ—Sr3—N1ⁱ	91.36 (9)	Sr1^viii—N3—Sr2	93.90 (11)
N4—Sr3—N1ⁱⁱ	96.81 (11)	Sr1^vii—N3—Sr2	93.90 (11)
N3ⁱⁱ—Sr3—N1ⁱⁱ	91.36 (9)	Sr4—N3—Sr2	172.85 (17)
N3ⁱ—Sr3—N1ⁱⁱ	163.18 (11)	Sr3^vii—N3—Sr2	83.52 (10)
N1ⁱ—Sr3—N1ⁱⁱ	79.31 (11)	Sr3^viii—N3—Sr2	83.52 (10)
N4—Sr3—C5ⁱ	119.71 (11)	Sr3—N4—Sr4^xi	97.01 (11)
N3ⁱⁱ—Sr3—C5ⁱ	142.10 (13)	Sr3—N4—Sr4^xii	97.01 (11)
N3ⁱ—Sr3—C5ⁱ	82.16 (10)	Sr4^xi—N4—Sr4^xii	99.84 (13)
N1ⁱ—Sr3—C5ⁱ	23.76 (12)	Sr3—N4—Sr2ⁱⁱ	87.32 (10)
N1ⁱⁱ—Sr3—C5ⁱ	83.82 (9)	Sr4^xi—N4—Sr2ⁱⁱ	173.62 (16)
N4—Sr3—C5ⁱⁱ	119.71 (11)	Sr4^xii—N4—Sr2ⁱⁱ	84.211 (15)
N3ⁱⁱ—Sr3—C5ⁱⁱ	82.16 (10)	Sr3—N4—Sr2ⁱ	87.32 (10)
N3ⁱ—Sr3—C5ⁱⁱ	142.10 (13)	Sr4^xi—N4—Sr2ⁱ	84.211 (15)
N1ⁱ—Sr3—C5ⁱⁱ	83.82 (9)	Sr4^xii—N4—Sr2ⁱ	173.62 (16)
N1ⁱⁱ—Sr3—C5ⁱⁱ	23.76 (12)	Sr2ⁱⁱ—N4—Sr2ⁱ	91.34 (12)
C5ⁱ—Sr3—C5ⁱⁱ	78.50 (12)	Sr3—N4—Sr2^xiii	171.22 (17)
N4—Sr3—Sr1	100.28 (9)	Sr4^xi—N4—Sr2^xiii	88.61 (10)
N3ⁱⁱ—Sr3—Sr1	47.03 (6)	Sr4^xii—N4—Sr2^xiii	88.61 (10)
N3ⁱ—Sr3—Sr1	47.03 (6)	Sr2ⁱⁱ—N4—Sr2^xiii	86.55 (10)
N1ⁱ—Sr3—Sr1	136.66 (6)	Sr2ⁱ—N4—Sr2^xiii	86.55 (10)
N1ⁱⁱ—Sr3—Sr1	136.66 (6)	N2—C5—N1	178.0 (5)
C5ⁱ—Sr3—Sr1	119.81 (9)	N2—C5—Sr1	76.9 (3)
C5ⁱⁱ—Sr3—Sr1	119.81 (9)	N1—C5—Sr1	101.1 (3)
N4—Sr3—Sr2ⁱⁱ	48.48 (6)	N2—C5—Sr3^vii	104.6 (3)
N3ⁱⁱ—Sr3—Sr2ⁱⁱ	49.73 (9)	N1—C5—Sr3^vii	76.9 (2)
N3ⁱ—Sr3—Sr2ⁱⁱ	97.93 (8)	Sr1—C5—Sr3^vii	140.38 (6)
N1ⁱ—Sr3—Sr2ⁱⁱ	144.92 (8)	N2—C5—Sr3^viii	104.6 (3)
N1ⁱⁱ—Sr3—Sr2ⁱⁱ	97.70 (7)	N1—C5—Sr3^viii	76.9 (2)
C5ⁱ—Sr3—Sr2ⁱⁱ	168.16 (9)	Sr1—C5—Sr3^viii	140.38 (6)
C5ⁱⁱ—Sr3—Sr2ⁱⁱ	107.47 (6)	Sr3^vii—C5—Sr3^viii	78.50 (12)
Sr1—Sr3—Sr2ⁱⁱ	66.676 (11)

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

Experimental details

Crystal data
Chemical formula	Sr₄N₂(CN₂)
M_r	418.53
Crystal system, space group	Orthorhombic, Pnma
Temperature (K)	150
a, b, c (Å)	12.2928 (4), 3.8261 (1), 14.3291 (5)
V (Å³)	673.95 (4)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	31.39
Crystal size (mm)	0.09 × 0.05 × 0.02

Data collection
Diffractometer	Nonius KappaCCD diffractometer
Absorption correction	Analytical (Alcock, 1970)
T_min, T_max	0.062, 0.301
No. of measured, independent and observed [I > 2σ(I)] reflections	14693, 1156, 942
R_int	0.076
(sin θ/λ)_max (Å⁻¹)	0.714

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.026, 0.050, 1.07
No. of reflections	1156
No. of parameters	56
Δρ_max, Δρ_min (e Å⁻³)	1.12, −0.99

Computer programs: COLLECT (Nonius, 2000), SCALEPACK (Otwinowski & Minor, 1997), SCALEPACK and DENZO (Otwinowski & Minor, 1997), SHELX97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ATOMS (Dowty, 2005), WinGX (Farrugia, 1999).

Selected geometric parameters (Å, º) top

Sr1—N3ⁱ	2.551 (3)	Sr3—N4	2.490 (4)
Sr1—N3ⁱⁱ	2.551 (3)	Sr3—N3ⁱⁱ	2.616 (3)
Sr1—N2	2.799 (4)	Sr3—N3ⁱ	2.616 (3)
Sr1—N1ⁱⁱⁱ	2.837 (3)	Sr3—N1ⁱ	2.998 (3)
Sr1—N1^iv	2.837 (3)	Sr3—N1ⁱⁱ	2.998 (3)
Sr2—N4^v	2.674 (3)	Sr4—N4^viii	2.500 (2)
Sr2—N4^vi	2.674 (3)	Sr4—N4^ix	2.500 (2)
Sr2—N3	2.740 (4)	Sr4—N3	2.592 (4)
Sr2—N4^vii	2.774 (4)	Sr4—N2	2.683 (4)
Sr2—N2^vi	2.867 (3)	N1—C5	1.240 (6)
Sr2—N2^v	2.867 (3)	N2—C5	1.235 (6)

N2—C5—N1	178.0 (5)

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

Footnotes

‡Current address: Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, England.

References

Alcock, N. W. (1970). Crystallographic Computing, Proceedings of the International Summer School, edited by S. R. Hall, pp. 271–278. Copenhagen: Munksgaard. Google Scholar
Dowty, E. (2005). ATOMS. Version 6-2. Shape Software, 521 Hidden Valley Road, Kingsport, TN 37663, USA. Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Höhn, P., Niewa, R. & Kniep R. (2000). Z. Kristallogr. New Cryst. Struct. 215, 323–324. Google Scholar
Nonius (2000). COLLECT. Nonius BV, Delft, The Netherlands. Google Scholar
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press. Google Scholar
Reckeweg, O. & DiSalvo, F. J. (2000). Angew. Chem. Int. Ed. 39, 412–414. CrossRef CAS Google Scholar
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. Release 97-2. University of Göttingen, Germany. Google Scholar
Yamane, H. & DiSalvo, F. J. (1996). J. Alloys Compd. 240, 33–36. CrossRef CAS Web of Science Google Scholar

© International Union of Crystallography. Prior permission is not required to reproduce short quotations, tables and figures from this article, provided the original authors and source are cited. For more information, click here.

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 61| Part 10| October 2005| Pages i221-i222

doi:10.1107/S1600536805030850

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Plain Text

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Plain Text

Search IUCr Journals		doi		Advanced search
Author		volume	page

inorganic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)