I(8)Sb(10)Ge(36).

Single crystals of the title compound, octa-iodide deca-anti-monate hexa-tria-conta-germanide, were grown by chemical transport reactions. The structure is isotypic with the analogous clathrates-I. In this structure, the (Ge,Sb)(46) framework consists of statistically occupied Ge and Sb sites that atoms form bonds in a distorted tetra-hedral arrangement. They form polyhedra that are covalently bonded to each other by shared faces. There are two polyhedra of different sizes, viz. a (Ge,Sb)(20) dodeca-hedron and a (Ge,Sb)(24) tetra-cosa-hedron in a 1:3 ratio. The guest atom (iodine) resides inside these polyhedra with symmetry m3 (Wyckoff position 2a) and 2m (Wyckoff position 2d), respectively.

Littérature associée

La synthèse en phase vapeur des premiers clathrates X 8Ge38 A 8 (X = Cl, Br, I; A = P, As, Sb) etait décrite par Menke & von Schnering (1973 ▶) et von Schnering & Menke (1976 ▶). Les structures sont isotypes aux hydrates de gaz correspondants (Pauling & Marsh, 1952 ▶). Pour les propriétés semiconductrices et thermoélectriques, voir respectivement Chu et al. (1982 ▶) et Kishimoto et al. (2006 ▶). Pour les propriétés structurales et la conductivité thermique, voir Nolas et al. (2000 ▶) et Shimizu et al. (2009 ▶). L’histoire et les développements récents des composés type clathrate du silicium et des éléments de la colonne 14 ont été relatés par Cros & Pouchard (2009 ▶). L’étude par diffraction électronique et HRTEM du clathrate I8Ge40.0Te5.3 a été réalisée par Kovnir et al. (2006 ▶). Pour autres composés type clathrate du germanium, voir Ayouz (2009 ▶); Latturner et al. (2000 ▶); Nesper et al. (1986 ▶).

Partie expérimentale

Données crystallines

I8Sb10Ge36

M = 4834,8

Cubique,

a = 10,8907 (2) Å

V = 1291,72 (3) Å3

Z = 1

Mo Kα radiation

μ = 30,49 mm−1

T = 150 K

0,10 × 0,08 × 0,07 mm

Collection des données

Diffractomètre Bruker APEXII

Correction d’absorption: multi-scan (SADABS; Sheldrick, 2002 ▶) T min = 0,082, T max = 0,116

27124 réflexions mesurées

1003 réflexions indépendantes

900 réflexions avec I > 3σ(I)

R int = 0,041

Affinement

R[F 2 > 2σ(F 2)] = 0,037

wR(F 2) = 0,091

S = 2,00

1003 réflexions

18 paramètres

3 restraintes

Δρmax = 1,48 e Å−3

Δρmin = −2,97 e Å−3

Collection des données: SAINT (Bruker, 2002 ▶); affinement des paramètres de la maille: SAINT; reduction des données: SAINT; programme(s) pour la solution de la structure: SHELXS97 (Sheldrick, 2008 ▶); programme(s) pour l’affinement de la structure: JANA2000 (Petříček et al., 2000 ▶); graphisme moléculaire: DIAMOND (Brandenburg & Putz, 2009 ▶); logiciel utilisé pour préparer le matériel pour publication: JANA2000.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810017496/br2144sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810017496/br2144Isup2.hkl

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

I8Sb10Ge36	Dx = 6.213 Mg m−3
Mr = 4834.8	Mo Kα radiation, λ = 0.71073 Å
Cubic, Pm3n	Cell parameters from 6120 reflections
Hall symbol: -P 4n 2 3	θ = 2.6–45.3°
a = 10.8907 (2) Å	µ = 30.49 mm−1
V = 1291.72 (3) Å3	T = 150 K
Z = 1	Cubic, black
F(000) = 2082	0.10 × 0.08 × 0.07 mm

Bruker APEXII diffractometer	1003 independent reflections
Radiation source: fine-focus sealed tube	900 reflections with I > 3σ(I)
graphite	Rint = 0.041
CCD rotation images, thin slices scans	θmax = 45.3°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	h = −21→18
Tmin = 0.082, Tmax = 0.116	k = −21→21
27124 measured reflections	l = −20→20

Refinement on F	3 restraints
R[F2 > 2σ(F2)] = 0.037	Weighting scheme based on measured s.u.'s w = 1/[σ2(F) + 0.001444F2]
wR(F2) = 0.091	(Δ/σ)max = 0.0004
S = 2.00	Δρmax = 1.48 e Å−3
1003 reflections	Δρmin = −2.97 e Å−3
18 parameters

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors are based on F, with F set to zero for negative F2. The threshold expression of F2 > n*σ(F2) is used only for calculating R-factors etc. and is not relevant to the choice of reflections for refinement. The program used for refinement, Jana2000, 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 then the ones from the SHELX program.

	x	y	z	Uiso*/Ueq	Occ. (<1)
I1	0	0	0	0.00492 (8)
I2	0.25	0.5	0	0.00789 (9)
Ge1	0.11736 (4)	0	0.30899 (4)	0.00934 (11)	0.823 (7)
Ge2	0.18365 (2)	0.18365 (2)	0.18365 (2)	0.00749 (8)	0.699 (8)
Sb3	0.25	0	0.5	0.00867 (17)	0.118 (11)
Sb1	0.117356	0	0.308994	0.00934 (11)	0.177 (7)
Sb2	0.18365	0.18365	0.18365	0.00749 (8)	0.301 (8)
Ge3	0.25	0	0.5	0.00867 (17)	0.882 (11)

	U11	U22	U33	U12	U13	U23
I1	0.00492 (14)	0.00492 (14)	0.00492 (14)	0	0	0
I2	0.00455 (18)	0.00956 (15)	0.00956 (15)	0	0	0
Ge1	0.00836 (18)	0.00909 (18)	0.01058 (19)	0	−0.00110 (11)	0
Ge2	0.00749 (14)	0.00749 (14)	0.00749 (14)	0.00030 (7)	0.00030 (7)	0.00030 (7)
Sb3	0.0117 (4)	0.0071 (3)	0.0071 (3)	0	0	0
Sb1	0.00836 (18)	0.00909 (18)	0.01058 (19)	0	−0.00110 (11)	0
Sb2	0.00749 (14)	0.00749 (14)	0.00749 (14)	0.00030 (7)	0.00030 (7)	0.00030 (7)
Ge3	0.0117 (4)	0.0071 (3)	0.0071 (3)	0	0	0

I1—Ge1	3.5997 (4)	I2—Ge1xix	3.6570 (3)
I1—Ge1i	3.5997 (4)	I2—Ge1viii	3.6570 (3)
I1—Ge1ii	3.5997 (4)	I2—Ge1xx	3.6570 (3)
I1—Ge1iii	3.5997 (4)	I2—Ge1xxi	3.6570 (3)
I1—Ge1iv	3.5997 (4)	I2—Ge1xi	3.6570 (3)
I1—Ge1v	3.5997 (4)	I2—Sb3xvi	3.8504
I1—Ge1vi	3.5997 (4)	I2—Sb3xvii	3.8504
I1—Ge1vii	3.5997 (4)	I2—Sb3xxii	3.8504
I1—Ge1viii	3.5997 (4)	I2—Sb3xxiii	3.8504
I1—Ge1ix	3.5997 (4)	I2—Sb1xvi	3.657
I1—Ge1x	3.5997 (4)	I2—Sb1xvii	3.657
I1—Ge1xi	3.5997 (4)	I2—Sb1xviii	3.657
I1—Ge2	3.4642 (3)	I2—Sb1xix	3.657
I1—Ge2i	3.4642 (3)	I2—Sb1viii	3.657
I1—Ge2ii	3.4642 (3)	I2—Sb1xx	3.657
I1—Ge2iii	3.4642 (3)	I2—Sb1xxi	3.657
I1—Ge2xii	3.4642 (3)	I2—Sb1xi	3.657
I1—Ge2xiii	3.4642 (3)	I2—Ge3xvi	3.8504
I1—Ge2xiv	3.4642 (3)	I2—Ge3xvii	3.8504
I1—Ge2xv	3.4642 (3)	I2—Ge3xxii	3.8504
I1—Sb1	3.5997	I2—Ge3xxiii	3.8504
I1—Sb1i	3.5997	Ge1—Ge1iii	2.5562 (6)
I1—Sb1ii	3.5997	Ge1—Ge2	2.5269 (4)
I1—Sb1iii	3.5997	Ge1—Ge2xv	2.5269 (4)
I1—Sb1iv	3.5997	Ge1—Sb3	2.5326 (4)
I1—Sb1v	3.5997	Ge1—Sb1iii	2.5562 (4)
I1—Sb1vi	3.5997	Ge1—Sb2	2.5269 (3)
I1—Sb1vii	3.5997	Ge1—Sb2xv	2.5269 (3)
I1—Sb1viii	3.5997	Ge1—Ge3	2.5326 (4)
I1—Sb1ix	3.5997	Ge2—Ge2xxiv	2.5032 (4)
I1—Sb1x	3.5997	Ge2—Sb1	2.5269 (3)
I1—Sb1xi	3.5997	Ge2—Sb1iv	2.5269 (3)
I1—Sb2	3.4642	Ge2—Sb1viii	2.5269 (3)
I1—Sb2i	3.4642	Ge2—Sb2xxiv	2.5032 (3)
I1—Sb2ii	3.4642	Sb3—Sb1	2.5326
I1—Sb2iii	3.4642	Sb3—Sb1xxv	2.5326
I1—Sb2xii	3.4642	Sb3—Sb1xxvi	2.5326
I1—Sb2xiii	3.4642	Sb3—Sb1xxvii	2.5326
I1—Sb2xiv	3.4642	Sb1—Sb1iii	2.5562
I1—Sb2xv	3.4642	Sb1—Sb2	2.5269
I2—Ge1xvi	3.6570 (3)	Sb1—Sb2xv	2.5269
I2—Ge1xvii	3.6570 (3)	Sb1—Ge3	2.5326
I2—Ge1xviii	3.6570 (3)	Sb2—Sb2xxiv	2.5032