Crystal structure of 2,2,3,3-tetra-methyl-1,1,1,4,4,4-hexa-phenyl-tetra-germane.

The mol-ecule of the title compound, C40H42Ge4, lies with its central Ge-Ge bond on an inversion centre giving rise to a zigzag backbone of four tetra-hedrally coordinated Ge atoms. The symmetrically independent Ge-Ge bonds are slightly shorter than in other organo-tetra-germanes whereas the Ge-CPh (Ph = phen-yl) and Ge-CMe (Me = meth-yl) distances have their usual values. In the crystal, (010) layers of Ph6Me4Ge4 mol-ecules with a parallel orientation of the Ge4 backbone exist, held together by van der Waals forces only. Main bond lengths in organo-substituted oligogermanes are compared.

Related literature

A search for ‘organic electronics’ materials in systems of conjugated C—C bonds (Kobayashi et al., 2011 ▶) was recently extended to organometallic mol­ecules containing chains of atoms such as Ge, Si, or Sn (Marschner & Hlina, 2013 ▶). The established routines used to obtain oligogermanes via hydro­germolysis or the reaction of germyllithium reagents with germanium halogenides (Amadoruge & Weinert, 2008 ▶) may give rise to unexpected by-products due to side reactions. As a part of our studies of the chemistry of oligogermanium compounds (Zaitsev et al., 2012 ▶, 2013 ▶, 2014 ▶), the title compound was obtained as a by-product. For related crystal structures of organo­tetra­germanes, see: Roller et al. (1986 ▶); Dräger & Simon (1986 ▶); Wagner et al. (2009 ▶); Amadoruge et al. (2010 ▶).

Experimental

Crystal data

C40H42Ge4

M = 813.10

Monoclinic,

a = 9.6402 (5) Å

b = 13.6386 (6) Å

c = 14.0503 (7) Å

β = 104.560 (1)°

V = 1787.99 (15) Å3

Z = 2

Mo Kα radiation

μ = 3.36 mm−1

T = 120 K

0.55 × 0.53 × 0.11 mm

Data collection

Bruker APEXII CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T min = 0.391, T max = 0.701

22283 measured reflections

5210 independent reflections

4222 reflections with I > 2σ(I)

R int = 0.039

Refinement

R[F 2 > 2σ(F 2)] = 0.030

wR(F 2) = 0.066

S = 1.05

5210 reflections

202 parameters

H-atom parameters constrained

Δρmax = 0.62 e Å−3

Δρmin = −0.39 e Å−3

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S160053681402501X/wm5086sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681402501X/wm5086Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S160053681402501X/wm5086Isup3.cml

Click here for additional data file.

x y z . DOI: 10.1107/S160053681402501X/wm5086fig1.tif

A view of the title mol­ecule showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen atoms are omitted for clarity. [Symmetry operator (A) −x + 1, −y + 1, −z + 1.]

CCDC reference: 1034201

Additional supporting information: crystallographic information; 3D view; checkCIF report

C40H42Ge4	F(000) = 820
Mr = 813.10	Dx = 1.510 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 7722 reflections
a = 9.6402 (5) Å	θ = 2.2–32.5°
b = 13.6386 (6) Å	µ = 3.36 mm−1
c = 14.0503 (7) Å	T = 120 K
β = 104.560 (1)°	Prism, colourless
V = 1787.99 (15) Å3	0.55 × 0.53 × 0.11 mm
Z = 2

Bruker APEXII CCD diffractometer	5210 independent reflections
Radiation source: fine-focus sealed tube	4222 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.039
φ and ω scans	θmax = 30.0°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −13→13
Tmin = 0.391, Tmax = 0.701	k = −19→19
22283 measured reflections	l = −19→19

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.030	H-atom parameters constrained
wR(F2) = 0.066	w = 1/[σ2(Fo2) + (0.0262P)2 + 0.6663P] where P = (Fo2 + 2Fc2)/3
S = 1.05	(Δ/σ)max = 0.001
5210 reflections	Δρmax = 0.62 e Å−3
202 parameters	Δρmin = −0.39 e Å−3
0 restraints	Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0062 (3)

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.

	x	y	z	Uiso*/Ueq
Ge1	0.44925 (2)	0.553177 (15)	0.551768 (15)	0.01582 (6)
Ge2	0.35670 (2)	0.459956 (15)	0.670324 (16)	0.01586 (6)
C1	0.5900 (3)	0.65022 (16)	0.61880 (17)	0.0266 (5)
H1A	0.6311	0.6837	0.5705	0.040*
H1B	0.6665	0.6172	0.6675	0.040*
H1C	0.5430	0.6983	0.6520	0.040*
C2	0.2832 (2)	0.62288 (17)	0.47117 (16)	0.0264 (5)
H2A	0.3153	0.6698	0.4284	0.040*
H2B	0.2340	0.6580	0.5140	0.040*
H2C	0.2171	0.5757	0.4308	0.040*
C3	0.2686 (2)	0.33907 (14)	0.60806 (14)	0.0175 (4)
C4	0.1389 (2)	0.34120 (15)	0.53599 (16)	0.0224 (4)
H4A	0.0886	0.4014	0.5208	0.027*
C5	0.0824 (2)	0.25622 (17)	0.48630 (17)	0.0264 (5)
H5A	−0.0056	0.2588	0.4372	0.032*
C6	0.1544 (2)	0.16757 (16)	0.50815 (17)	0.0256 (5)
H6A	0.1155	0.1097	0.4742	0.031*
C7	0.2829 (2)	0.16369 (15)	0.57958 (16)	0.0236 (4)
H7A	0.3320	0.1031	0.5949	0.028*
C8	0.3399 (2)	0.24892 (15)	0.62893 (15)	0.0201 (4)
H8A	0.4285	0.2459	0.6775	0.024*
C9	0.5064 (2)	0.42690 (14)	0.78825 (15)	0.0170 (4)
C10	0.4757 (2)	0.41586 (16)	0.87949 (16)	0.0227 (4)
H10A	0.3798	0.4234	0.8844	0.027*
C11	0.5827 (3)	0.39404 (16)	0.96343 (16)	0.0255 (5)
H11A	0.5593	0.3861	1.0247	0.031*
C12	0.7234 (2)	0.38385 (15)	0.95799 (16)	0.0249 (5)
H12A	0.7968	0.3701	1.0155	0.030*
C13	0.7560 (2)	0.39384 (16)	0.86836 (16)	0.0244 (5)
H13A	0.8521	0.3859	0.8641	0.029*
C14	0.6489 (2)	0.41554 (15)	0.78413 (16)	0.0204 (4)
H14A	0.6730	0.4227	0.7230	0.024*
C15	0.2120 (2)	0.53782 (15)	0.71306 (15)	0.0182 (4)
C16	0.2365 (2)	0.63689 (15)	0.73511 (16)	0.0222 (4)
H16A	0.3224	0.6664	0.7276	0.027*
C17	0.1380 (2)	0.69347 (16)	0.76790 (16)	0.0245 (5)
H17A	0.1577	0.7606	0.7835	0.029*
C18	0.0110 (2)	0.65232 (17)	0.77794 (16)	0.0259 (5)
H18A	−0.0574	0.6911	0.7992	0.031*
C19	−0.0148 (3)	0.55397 (17)	0.7565 (2)	0.0317 (5)
H19A	−0.1011	0.5250	0.7639	0.038*
C20	0.0841 (2)	0.49707 (16)	0.72433 (18)	0.0266 (5)
H20A	0.0645	0.4297	0.7098	0.032*

	U11	U22	U33	U12	U13	U23
Ge1	0.01786 (11)	0.01507 (10)	0.01456 (11)	0.00087 (7)	0.00413 (8)	0.00019 (8)
Ge2	0.01524 (11)	0.01695 (11)	0.01510 (11)	−0.00037 (8)	0.00329 (8)	0.00050 (8)
C1	0.0321 (13)	0.0246 (11)	0.0233 (11)	−0.0078 (9)	0.0076 (9)	−0.0030 (9)
C2	0.0299 (12)	0.0282 (11)	0.0200 (11)	0.0107 (9)	0.0043 (9)	0.0031 (9)
C3	0.0166 (10)	0.0214 (10)	0.0148 (9)	−0.0012 (7)	0.0046 (8)	0.0004 (7)
C4	0.0214 (11)	0.0225 (10)	0.0217 (11)	0.0004 (8)	0.0022 (8)	0.0021 (8)
C5	0.0223 (11)	0.0319 (12)	0.0225 (11)	−0.0049 (9)	0.0011 (9)	−0.0019 (9)
C6	0.0258 (12)	0.0261 (11)	0.0259 (12)	−0.0071 (9)	0.0084 (9)	−0.0065 (9)
C7	0.0257 (11)	0.0202 (10)	0.0261 (12)	0.0005 (8)	0.0086 (9)	0.0013 (8)
C8	0.0188 (10)	0.0232 (10)	0.0182 (10)	−0.0003 (8)	0.0045 (8)	0.0028 (8)
C9	0.0187 (10)	0.0144 (9)	0.0169 (10)	−0.0015 (7)	0.0027 (8)	0.0004 (7)
C10	0.0221 (11)	0.0240 (10)	0.0226 (11)	−0.0007 (8)	0.0068 (9)	0.0019 (8)
C11	0.0320 (12)	0.0276 (11)	0.0166 (10)	0.0007 (9)	0.0056 (9)	0.0048 (8)
C12	0.0293 (12)	0.0216 (10)	0.0198 (11)	0.0020 (8)	−0.0011 (9)	0.0023 (8)
C13	0.0209 (11)	0.0254 (11)	0.0258 (12)	0.0037 (8)	0.0035 (9)	0.0027 (9)
C14	0.0203 (10)	0.0236 (10)	0.0179 (10)	0.0026 (8)	0.0060 (8)	0.0011 (8)
C15	0.0172 (9)	0.0225 (10)	0.0146 (9)	0.0008 (8)	0.0031 (7)	0.0026 (8)
C16	0.0193 (10)	0.0243 (10)	0.0227 (11)	−0.0040 (8)	0.0051 (8)	−0.0038 (8)
C17	0.0266 (12)	0.0243 (10)	0.0219 (11)	0.0004 (9)	0.0048 (9)	−0.0047 (8)
C18	0.0255 (12)	0.0315 (12)	0.0225 (11)	0.0071 (9)	0.0096 (9)	0.0010 (9)
C19	0.0214 (11)	0.0352 (13)	0.0427 (15)	−0.0027 (9)	0.0162 (10)	0.0027 (11)
C20	0.0243 (12)	0.0235 (11)	0.0345 (13)	−0.0027 (9)	0.0117 (10)	0.0006 (9)

Ge1—C2	1.959 (2)	C8—H8A	0.9500
Ge1—C1	1.959 (2)	C9—C10	1.394 (3)
Ge1—Ge1i	2.4276 (4)	C9—C14	1.398 (3)
Ge1—Ge2	2.4361 (3)	C10—C11	1.390 (3)
Ge2—C9	1.957 (2)	C10—H10A	0.9500
Ge2—C3	1.957 (2)	C11—C12	1.384 (3)
Ge2—C15	1.963 (2)	C11—H11A	0.9500
C1—H1A	0.9800	C12—C13	1.379 (3)
C1—H1B	0.9800	C12—H12A	0.9500
C1—H1C	0.9800	C13—C14	1.393 (3)
C2—H2A	0.9800	C13—H13A	0.9500
C2—H2B	0.9800	C14—H14A	0.9500
C2—H2C	0.9800	C15—C16	1.393 (3)
C3—C4	1.398 (3)	C15—C20	1.397 (3)
C3—C8	1.403 (3)	C16—C17	1.390 (3)
C4—C5	1.391 (3)	C16—H16A	0.9500
C4—H4A	0.9500	C17—C18	1.386 (3)
C5—C6	1.389 (3)	C17—H17A	0.9500
C5—H5A	0.9500	C18—C19	1.383 (3)
C6—C7	1.386 (3)	C18—H18A	0.9500
C6—H6A	0.9500	C19—C20	1.391 (3)
C7—C8	1.394 (3)	C19—H19A	0.9500
C7—H7A	0.9500	C20—H20A	0.9500
C2—Ge1—C1	108.47 (10)	C7—C8—C3	121.03 (19)
C2—Ge1—Ge1i	109.73 (7)	C7—C8—H8A	119.5
C1—Ge1—Ge1i	110.91 (7)	C3—C8—H8A	119.5
C2—Ge1—Ge2	105.19 (7)	C10—C9—C14	117.63 (19)
C1—Ge1—Ge2	110.63 (7)	C10—C9—Ge2	121.46 (16)
Ge1i—Ge1—Ge2	111.715 (14)	C14—C9—Ge2	120.90 (15)
C9—Ge2—C3	109.21 (8)	C11—C10—C9	121.3 (2)
C9—Ge2—C15	107.16 (9)	C11—C10—H10A	119.3
C3—Ge2—C15	109.31 (8)	C9—C10—H10A	119.3
C9—Ge2—Ge1	112.36 (6)	C12—C11—C10	120.2 (2)
C3—Ge2—Ge1	109.04 (6)	C12—C11—H11A	119.9
C15—Ge2—Ge1	109.71 (6)	C10—C11—H11A	119.9
Ge1—C1—H1A	109.5	C13—C12—C11	119.5 (2)
Ge1—C1—H1B	109.5	C13—C12—H12A	120.3
H1A—C1—H1B	109.5	C11—C12—H12A	120.3
Ge1—C1—H1C	109.5	C12—C13—C14	120.4 (2)
H1A—C1—H1C	109.5	C12—C13—H13A	119.8
H1B—C1—H1C	109.5	C14—C13—H13A	119.8
Ge1—C2—H2A	109.5	C13—C14—C9	121.0 (2)
Ge1—C2—H2B	109.5	C13—C14—H14A	119.5
H2A—C2—H2B	109.5	C9—C14—H14A	119.5
Ge1—C2—H2C	109.5	C16—C15—C20	117.75 (19)
H2A—C2—H2C	109.5	C16—C15—Ge2	119.92 (15)
H2B—C2—H2C	109.5	C20—C15—Ge2	122.31 (16)
C4—C3—C8	118.14 (19)	C17—C16—C15	121.4 (2)
C4—C3—Ge2	120.99 (15)	C17—C16—H16A	119.3
C8—C3—Ge2	120.67 (15)	C15—C16—H16A	119.3
C5—C4—C3	120.8 (2)	C18—C17—C16	120.3 (2)
C5—C4—H4A	119.6	C18—C17—H17A	119.9
C3—C4—H4A	119.6	C16—C17—H17A	119.9
C6—C5—C4	120.2 (2)	C19—C18—C17	119.1 (2)
C6—C5—H5A	119.9	C19—C18—H18A	120.5
C4—C5—H5A	119.9	C17—C18—H18A	120.5
C7—C6—C5	119.9 (2)	C18—C19—C20	120.7 (2)
C7—C6—H6A	120.0	C18—C19—H19A	119.6
C5—C6—H6A	120.0	C20—C19—H19A	119.6
C6—C7—C8	119.9 (2)	C19—C20—C15	120.8 (2)
C6—C7—H7A	120.1	C19—C20—H20A	119.6
C8—C7—H7A	120.1	C15—C20—H20A	119.6

Table 1

Main bond lengths () in organo-substituted oligogermanes

Me is CH3, Ms is Me3Si and Tol is p-C6H4Me.

Compound	GeGeperiph	GeGecentral	GeCPh	GeCMe
Ph3GeMe2GeGeMe2GePh3 a	2.4361(3)	2.4276(4)	1.961	1.965
Ms3GeMe2GeGeMe2GeMs3 b	2.441	2.442		1.967
Tol3GeGePh2GePh2GeTol3 c	2.443	2.457	1.973
Ph3GeGePh2GePh2GePh3 d	2.464	2.461	1.969
Ph3GeGeMe2GePh3 e	2.429		1.957	1.944

References: (a) This work; (b) Wagner et al. (2009 ▶); (c) Amadoruge et al. (2010 ▶); (d) Roller et al. (1986 ▶); (e) Drger Simon (1986 ▶).