Download citation
Download citation
link to html
Single crystals of germanium(IV) tetrachloride, GeCl4, were grown at 193 K. In the crystal structure, the isolated mol­ecules have very well realised tetrahedral geometry.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102010351/br1378sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270102010351/br1378Isup2.hkl
Contains datablock I

Comment top

Germanium(IV) chloride is an important intermediate in the purifaction for semiconductor-grade germanium (Fisher & Teal 1951) and in the preparation of organogermanium compounds via LiR or RMgX reagents (Betka & Grobe, 1985). The title compound is a colourless volatile liquid with a melting point of 223.5 K. The structure chemistry of the group IV elements affords abundant illustrations of the trends to be expected from increasing atomic size and electropositivity. In contrast to the homologous compounds silicon(IV) chloride and tin(IV) chloride, the crystal structure of germanium(IV) chloride is unknown. It is of interest whether the so far unknown crystal structure of germanium(IV) chloride is similar to those of silicon(IV) chloride (Zakharov et al., 1986) and tin(IV) chloride (Reuter & Pawlak, 1999). We report here the structure and the crystal packing of the title compound and a comparison of the crystal structures of ECl4 with E = C, Si, Ge, Sn.

The title molecule is shown in Fig. 1, with the associated dimensions given in Table 1. Solid-state germanium (IV) chloride consists of isolated molecules which are held together by van der Waals interactions. The asymmetrical unit consists of one molecule with the bond lengths and angles expected for tetrahedral symmetry. The mean Ge—Cl distances are in good agreement with the determined structures of the cocrystal Ge5Cl12 with GeCl4 showing 2.082 (7) Å (Beattie et al., 1998) and compared with the rGeCl determined by electron diffraction on the gaseous molecule [2.113 (3) Å; Morino et al., 1960]. The crystal structure of germanium(IV) chloride is isostructural with CCl4 (Piermarini, 1973), SiCl4 (Zakharov et al., 1986) and SnCl4 (Reuter & Pawlak, 1999). For comparison, the cell parameters of these tetrahalides are: CCl4: a = 9.07 (1) Å, b = 5.764 (3) Å, c = 9.201 (4) Å and β = 104.29 (5)°; SiCl4: a = 9.608 (4) Å, b = 6.356 (2) Å, c = 9.672 (4) Å and β = 102.909 (3)°; SnCl4: a = 9.864 (2) Å, b = 6.680 (1) Å, c = 9.937 (2) Å and β = 102.94 (1)°.

Similarities exist in the unit-cell dimensions, as well as their ratios, with the differences reflecting the relative size difference in the atoms of the various substances. The crystal packing of germanium(IV) chloride is shown in Fig. 2. An approach to the description of the crystal packing on the basis of the hexagonal-close packing for the isostructural compound SnCl4 is given by Reuter & Pawlak (1999). The tetrahedral molecules show Cl···Cl distances in the range 3.711 (5)–3.938 (5) Å, significantly longer than the normal van der Waals seperation of 3.6 Å.

Experimental top

The title compound was first distilled in high vacuum for purification and then transferred into an attached capillary. The sealed capilarry was transferred to the diffractometer with a detachable cooling device. Single crystals suitable for X-ray diffraction were grown with the in situ method by using a computer-controlled device that applies a focused CO2-laser beam along the capillary (Boese et al., 1999).

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Siemens, 1996); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures top
[Figure 1] Fig. 1. The molecular structure of germanium(IV) chloride, showing 50% probability displacement ellipsiods.
[Figure 2] Fig. 2. Crystal packing of the germanium(IV) chloride structure
(I) top
Crystal data top
GeCl4F(000) = 400
Mr = 214.39Dx = 2.393 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 347 reflections
a = 9.690 (3) Åθ = 3.2–21.3°
b = 6.451 (2) ŵ = 6.78 mm1
c = 9.774 (3) ÅT = 193 K
β = 103.075 (6)°Cylinder, colourless
V = 595.1 (4) Å30.4 × 0.2 × 0.2 mm
Z = 4
Data collection top
Siemens CCD area-detector
diffractometer
955 independent reflections
Radiation source: fine-focus sealed tube905 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.018
ω scansθmax = 25.0°, θmin = 3.8°
Absorption correction: multi-scan
?
h = 710
Tmin = 0.214, Tmax = 0.258k = 37
1423 measured reflectionsl = 1011
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.026 w = 1/[σ2(Fo2) + (0.0166P)2 + 0.5556P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.071(Δ/σ)max = 0.001
S = 1.27Δρmax = 0.54 e Å3
955 reflectionsΔρmin = 0.54 e Å3
47 parametersExtinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.0293 (19)
Crystal data top
GeCl4V = 595.1 (4) Å3
Mr = 214.39Z = 4
Monoclinic, P21/cMo Kα radiation
a = 9.690 (3) ŵ = 6.78 mm1
b = 6.451 (2) ÅT = 193 K
c = 9.774 (3) Å0.4 × 0.2 × 0.2 mm
β = 103.075 (6)°
Data collection top
Siemens CCD area-detector
diffractometer
955 independent reflections
Absorption correction: multi-scan
?
905 reflections with I > 2σ(I)
Tmin = 0.214, Tmax = 0.258Rint = 0.018
1423 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.02647 parameters
wR(F2) = 0.0710 restraints
S = 1.27Δρmax = 0.54 e Å3
955 reflectionsΔρmin = 0.54 e Å3
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
xyzUiso*/Ueq
Ge10.25164 (4)0.57350 (5)0.63977 (4)0.0232 (2)
Cl20.30205 (13)0.42188 (16)0.46770 (11)0.0426 (3)
Cl30.42835 (11)0.56946 (15)0.80965 (10)0.0375 (3)
Cl40.08347 (12)0.41974 (16)0.69787 (12)0.0428 (3)
Cl10.19210 (12)0.87990 (15)0.58530 (11)0.0405 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Ge10.0252 (3)0.0219 (3)0.0212 (3)0.00010 (13)0.00244 (17)0.00034 (13)
Cl20.0510 (7)0.0467 (6)0.0293 (5)0.0089 (5)0.0076 (5)0.0102 (4)
Cl30.0330 (6)0.0420 (6)0.0312 (5)0.0006 (4)0.0059 (4)0.0024 (4)
Cl40.0347 (7)0.0493 (7)0.0439 (6)0.0103 (4)0.0079 (5)0.0119 (4)
Cl10.0504 (7)0.0248 (5)0.0439 (6)0.0056 (4)0.0058 (5)0.0055 (4)
Geometric parameters (Å, º) top
Ge1—Cl42.0930 (12)Ge1—Cl22.0966 (12)
Ge1—Cl12.0938 (12)Ge1—Cl32.0984 (12)
Cl4—Ge1—Cl1109.25 (5)Cl4—Ge1—Cl3109.00 (5)
Cl4—Ge1—Cl2109.49 (5)Cl1—Ge1—Cl3109.97 (4)
Cl1—Ge1—Cl2109.71 (5)Cl2—Ge1—Cl3109.42 (5)

Experimental details

Crystal data
Chemical formulaGeCl4
Mr214.39
Crystal system, space groupMonoclinic, P21/c
Temperature (K)193
a, b, c (Å)9.690 (3), 6.451 (2), 9.774 (3)
β (°) 103.075 (6)
V3)595.1 (4)
Z4
Radiation typeMo Kα
µ (mm1)6.78
Crystal size (mm)0.4 × 0.2 × 0.2
Data collection
DiffractometerSiemens CCD area-detector
diffractometer
Absorption correctionMulti-scan
Tmin, Tmax0.214, 0.258
No. of measured, independent and
observed [I > 2σ(I)] reflections
1423, 955, 905
Rint0.018
(sin θ/λ)max1)0.594
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.026, 0.071, 1.27
No. of reflections955
No. of parameters47
Δρmax, Δρmin (e Å3)0.54, 0.54

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SAINT, SHELXTL (Siemens, 1996), SHELXTL.

Selected geometric parameters (Å, º) top
Ge1—Cl42.0930 (12)Ge1—Cl22.0966 (12)
Ge1—Cl12.0938 (12)Ge1—Cl32.0984 (12)
Cl4—Ge1—Cl1109.25 (5)Cl4—Ge1—Cl3109.00 (5)
Cl4—Ge1—Cl2109.49 (5)Cl1—Ge1—Cl3109.97 (4)
Cl1—Ge1—Cl2109.71 (5)Cl2—Ge1—Cl3109.42 (5)
 

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds