Complexes of germanium bromides with 4-picoline and 3,4-lutidine

The reactions of GeBr₄ with 4-methyl­pyridine and 3,4-di­methyl­pyridine lead to tetra­bromo­bis(4-methyl­pyridine)­germanium, [GeBr₄(C₆H₇N)₂], and tetra­bromo­bis(3,4-di­methyl­pyridine)­germanium, [GeBr₄(C₇H₉N)₂], respectively. These structures show the same features as the corresponding silicon complexes.

Computing details

For both compounds, data collection: SMART (Siemens, 1995); cell refinement: SMART; data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); software used to prepare material for publication: SHELXL97.

(I) ;

Crystal data

[GeBr4(C6H7N)2]	F(000) = 544
Mr = 578.48	Dx = 2.302 Mg m^−3
Orthorhombic, Pmna	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2	Cell parameters from 5051 reflections
a = 7.360 (1) Å	θ = 1–25°
b = 8.360 (1) Å	µ = 11.40 mm^−1
c = 13.561 (1) Å	T = 173 K
V = 834.40 (16) Å^3	Needle, yellow
Z = 2	0.36 × 0.16 × 0.10 mm

Data collection

Siemens CCD three-circle diffractometer	1122 independent reflections
Radiation source: fine-focus sealed tube	869 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.074
ω scans	θmax = 28.3°, θmin = 2.4°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −9→9
Tmin = 0.089, Tmax = 0.319	k = −11→11
14794 measured reflections	l = −18→18

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.028	H-atom parameters constrained
wR(F^2) = 0.056	w = 1/[σ^2(Fo^2) + (0.0202P)^2 + 1.2129P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
1122 reflections	Δρmax = 0.48 e Å^−3
57 parameters	Δρmin = −0.64 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0027 (3)

Special details

Experimental. ;

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 (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Br1	0.73632 (5)	0.16531 (4)	0.42513 (3)	0.03106 (13)
Ge1	0.5000	0.0000	0.5000	0.01701 (16)
N1	0.5000	0.1469 (4)	0.6241 (3)	0.0178 (8)
C2	0.5000	0.3075 (5)	0.6141 (3)	0.0222 (10)
H2	0.5000	0.3522	0.5497	0.027*
C3	0.5000	0.4082 (6)	0.6938 (4)	0.0255 (11)
H3	0.5000	0.5208	0.6840	0.031*
C4	0.5000	0.3459 (6)	0.7891 (3)	0.0223 (10)
C41	0.5000	0.4520 (6)	0.8782 (3)	0.0292 (11)
H41A	0.5000	0.5639	0.8596	0.044*	0.50
H41B	0.3975	0.4196	0.9183	0.044*	0.50
H41C	0.5000	0.3852	0.9367	0.044*	0.50
H41D	0.3929	0.5195	0.8757	0.044*	0.50
C5	0.5000	0.1803 (6)	0.7984 (3)	0.0240 (10)
H5	0.5000	0.1328	0.8620	0.029*
C6	0.5000	0.0850 (6)	0.7158 (3)	0.0221 (10)
H6	0.5000	−0.0279	0.7237	0.027*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0313 (2)	0.02804 (19)	0.0338 (2)	−0.01124 (16)	0.00933 (15)	−0.00716 (16)
Ge1	0.0182 (3)	0.0142 (3)	0.0186 (3)	0.000	0.000	−0.0030 (3)
N1	0.0200 (18)	0.0126 (18)	0.0208 (18)	0.000	0.000	−0.0046 (15)
C2	0.027 (2)	0.018 (2)	0.022 (2)	0.000	0.000	0.0002 (19)
C3	0.030 (3)	0.013 (2)	0.034 (3)	0.000	0.000	−0.004 (2)
C4	0.017 (2)	0.024 (2)	0.025 (2)	0.000	0.000	−0.009 (2)
C41	0.037 (3)	0.025 (3)	0.026 (3)	0.000	0.000	−0.010 (2)
C5	0.030 (2)	0.021 (2)	0.021 (2)	0.000	0.000	−0.002 (2)
C6	0.030 (2)	0.015 (2)	0.021 (2)	0.000	0.000	−0.0016 (19)

Geometric parameters (Å, º)

Br1—Ge1	2.4425 (4)	C3—H3	0.9500
Ge1—N1	2.083 (3)	C4—C5	1.391 (6)
Ge1—N1^i	2.083 (3)	C4—C41	1.498 (6)
Ge1—Br1^i	2.4425 (4)	C41—H41A	0.9693
Ge1—Br1^ii	2.4425 (4)	C41—H41B	0.9693
Ge1—Br1^iii	2.4425 (4)	C41—H41C	0.9699
N1—C6	1.347 (6)	C41—H41D	0.9701
N1—C2	1.350 (5)	C5—C6	1.374 (6)
C2—C3	1.369 (6)	C5—H5	0.9500
C2—H2	0.9500	C6—H6	0.9500
C3—C4	1.394 (7)
N1—Ge1—N1^i	180.0	C2—C3—H3	119.9
N1—Ge1—Br1	90.14 (7)	C4—C3—H3	119.9
N1^i—Ge1—Br1	89.86 (7)	C5—C4—C3	117.1 (4)
N1—Ge1—Br1^i	89.86 (7)	C5—C4—C41	121.1 (4)
N1^i—Ge1—Br1^i	90.14 (7)	C3—C4—C41	121.8 (4)
Br1—Ge1—Br1^i	180.0	C4—C41—H41A	111.2
N1—Ge1—Br1^ii	89.86 (7)	C4—C41—H41B	106.7
N1^i—Ge1—Br1^ii	90.14 (7)	H41A—C41—H41B	114.6
Br1—Ge1—Br1^ii	89.19 (2)	C4—C41—H41C	108.6
Br1^i—Ge1—Br1^ii	90.81 (2)	H41A—C41—H41C	140.2
N1—Ge1—Br1^iii	90.14 (7)	H41B—C41—H41C	51.7
N1^i—Ge1—Br1^iii	89.86 (7)	C4—C41—H41D	108.5
Br1—Ge1—Br1^iii	90.81 (2)	H41A—C41—H41D	55.2
Br1^i—Ge1—Br1^iii	89.19 (2)	H41B—C41—H41D	63.2
Br1^ii—Ge1—Br1^iii	180.000 (15)	H41C—C41—H41D	111.3
C6—N1—C2	118.3 (4)	C6—C5—C4	120.2 (4)
C6—N1—Ge1	121.3 (3)	C6—C5—H5	119.9
C2—N1—Ge1	120.3 (3)	C4—C5—H5	119.9
N1—C2—C3	122.2 (4)	N1—C6—C5	122.0 (4)
N1—C2—H2	118.9	N1—C6—H6	119.0
C3—C2—H2	118.9	C5—C6—H6	119.0
C2—C3—C4	120.1 (4)
N1^i—Ge1—N1—C6	180.0 (6)	C6—N1—C2—C3	0.000 (2)
Br1—Ge1—N1—C6	−134.594 (10)	Ge1—N1—C2—C3	180.000 (1)
Br1^i—Ge1—N1—C6	45.406 (10)	N1—C2—C3—C4	0.000 (2)
Br1^ii—Ge1—N1—C6	−45.406 (10)	C2—C3—C4—C5	0.000 (2)
Br1^iii—Ge1—N1—C6	134.594 (10)	C2—C3—C4—C41	180.000 (2)
N1^i—Ge1—N1—C2	0 (100)	C3—C4—C5—C6	0.000 (2)
Br1—Ge1—N1—C2	45.406 (10)	C41—C4—C5—C6	180.000 (2)
Br1^i—Ge1—N1—C2	−134.594 (10)	C2—N1—C6—C5	0.000 (2)
Br1^ii—Ge1—N1—C2	134.594 (10)	Ge1—N1—C6—C5	180.000 (1)
Br1^iii—Ge1—N1—C2	−45.406 (10)	C4—C5—C6—N1	0.000 (2)

Symmetry codes: (i) −x+1, −y, −z+1; (ii) x, −y, −z+1; (iii) −x+1, y, z.

(II) ;

Crystal data

[GeBr4(C7H9N)2]	Dx = 2.276 Mg m^−3
Mr = 606.53	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Cmca	Cell parameters from 3846 reflections
a = 7.477 (1) Å	θ = 1–25°
b = 17.942 (5) Å	µ = 10.76 mm^−1
c = 13.194 (3) Å	T = 173 K
V = 1770.0 (7) Å^3	Plate, yellow
Z = 4	0.22 × 0.12 × 0.05 mm
F(000) = 1152

Data collection

Siemens CCD three-circle diffractometer	1134 independent reflections
Radiation source: fine-focus sealed tube	898 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.099
ω scans	θmax = 27.8°, θmin = 2.8°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −9→9
Tmin = 0.200, Tmax = 0.580	k = −23→23
12371 measured reflections	l = −17→17

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.077	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0315P)^2 + 6.1521P] where P = (Fo^2 + 2Fc^2)/3
1134 reflections	(Δ/σ)max < 0.001
62 parameters	Δρmax = 0.62 e Å^−3
0 restraints	Δρmin = −0.78 e Å^−3

Special details

Experimental. ;

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 (Ų)

	x	y	z	Uiso*/Ueq
Ge1	0.5000	0.5000	0.5000	0.0149 (2)
Br1	0.73194 (6)	0.42244 (2)	0.42398 (3)	0.02444 (15)
N1	0.5000	0.4321 (3)	0.6297 (4)	0.0165 (10)
C2	0.5000	0.3577 (3)	0.6207 (5)	0.0183 (13)
H2	0.5000	0.3369	0.5544	0.022*
C3	0.5000	0.3095 (3)	0.7025 (4)	0.0172 (12)
C31	0.5000	0.2267 (3)	0.6870 (5)	0.0267 (15)
H31A	0.5000	0.2152	0.6144	0.040*
H31B	0.3932	0.2051	0.7185	0.040*
C4	0.5000	0.3412 (3)	0.8010 (5)	0.0180 (13)
C41	0.5000	0.2930 (4)	0.8943 (5)	0.0243 (14)
H41A	0.5000	0.3245	0.9550	0.036*
H41B	0.3933	0.2613	0.8941	0.036*
C5	0.5000	0.4181 (3)	0.8085 (5)	0.0219 (13)
H5	0.5000	0.4407	0.8737	0.026*
C6	0.5000	0.4626 (3)	0.7236 (5)	0.0239 (14)
H6	0.5000	0.5153	0.7309	0.029*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ge1	0.0177 (4)	0.0132 (4)	0.0137 (4)	0.000	0.000	0.0004 (4)
Br1	0.0261 (2)	0.0223 (2)	0.0249 (2)	0.00582 (19)	0.00608 (19)	0.00143 (19)
N1	0.018 (2)	0.019 (3)	0.013 (3)	0.000	0.000	0.000 (2)
C2	0.024 (3)	0.015 (3)	0.015 (3)	0.000	0.000	−0.008 (2)
C3	0.019 (3)	0.018 (3)	0.015 (3)	0.000	0.000	−0.002 (3)
C31	0.047 (4)	0.018 (3)	0.015 (3)	0.000	0.000	0.000 (3)
C4	0.017 (3)	0.020 (3)	0.017 (3)	0.000	0.000	0.005 (3)
C41	0.035 (4)	0.020 (3)	0.018 (3)	0.000	0.000	0.001 (3)
C5	0.030 (3)	0.021 (3)	0.015 (3)	0.000	0.000	−0.007 (3)
C6	0.034 (4)	0.015 (3)	0.023 (4)	0.000	0.000	0.000 (3)

Geometric parameters (Å, º)

Ge1—N1	2.101 (5)	C3—C31	1.501 (8)
Ge1—N1^i	2.101 (5)	C31—H31A	0.9800
Ge1—Br1^ii	2.4392 (5)	C31—H31B	0.9800
Ge1—Br1^i	2.4392 (5)	C4—C5	1.384 (8)
Ge1—Br1	2.4392 (5)	C4—C41	1.504 (8)
Ge1—Br1^iii	2.4392 (5)	C41—H41A	0.9799
N1—C2	1.341 (7)	C41—H41B	0.9801
N1—C6	1.354 (8)	C5—C6	1.376 (9)
C2—C3	1.383 (8)	C5—H5	0.9500
C2—H2	0.9500	C6—H6	0.9500
C3—C4	1.419 (8)
N1—Ge1—N1^i	180.0	C3—C2—H2	118.2
N1—Ge1—Br1^ii	89.76 (9)	C2—C3—C4	117.7 (5)
N1^i—Ge1—Br1^ii	90.24 (9)	C2—C3—C31	120.8 (5)
N1—Ge1—Br1^i	89.76 (9)	C4—C3—C31	121.5 (5)
N1^i—Ge1—Br1^i	90.24 (9)	C3—C31—H31A	110.0
Br1^ii—Ge1—Br1^i	90.63 (3)	C3—C31—H31B	109.4
N1—Ge1—Br1	90.24 (9)	H31A—C31—H31B	109.4
N1^i—Ge1—Br1	89.76 (9)	C5—C4—C3	117.7 (5)
Br1^ii—Ge1—Br1	89.37 (3)	C5—C4—C41	121.0 (6)
Br1^i—Ge1—Br1	180.0	C3—C4—C41	121.3 (5)
N1—Ge1—Br1^iii	90.24 (9)	C4—C41—H41A	109.7
N1^i—Ge1—Br1^iii	89.76 (9)	C4—C41—H41B	109.4
Br1^ii—Ge1—Br1^iii	180.0	H41A—C41—H41B	109.7
Br1^i—Ge1—Br1^iii	89.37 (3)	C6—C5—C4	121.3 (6)
Br1—Ge1—Br1^iii	90.63 (3)	C6—C5—H5	119.3
C2—N1—C6	119.0 (5)	C4—C5—H5	119.3
C2—N1—Ge1	120.3 (4)	N1—C6—C5	120.7 (6)
C6—N1—Ge1	120.7 (4)	N1—C6—H6	119.6
N1—C2—C3	123.5 (5)	C5—C6—H6	119.6
N1—C2—H2	118.2
N1^i—Ge1—N1—C2	1 (100)	N1—C2—C3—C4	0.000 (2)
Br1^ii—Ge1—N1—C2	−134.686 (13)	N1—C2—C3—C31	180.000 (2)
Br1^i—Ge1—N1—C2	134.686 (13)	C2—C3—C4—C5	0.000 (2)
Br1—Ge1—N1—C2	−45.314 (13)	C31—C3—C4—C5	180.000 (2)
Br1^iii—Ge1—N1—C2	45.313 (13)	C2—C3—C4—C41	180.000 (2)
N1^i—Ge1—N1—C6	−179 (100)	C31—C3—C4—C41	0.000 (2)
Br1^ii—Ge1—N1—C6	45.314 (13)	C3—C4—C5—C6	0.000 (3)
Br1^i—Ge1—N1—C6	−45.314 (13)	C41—C4—C5—C6	180.000 (2)
Br1—Ge1—N1—C6	134.686 (13)	C2—N1—C6—C5	0.000 (3)
Br1^iii—Ge1—N1—C6	−134.687 (13)	Ge1—N1—C6—C5	180.000 (2)
C6—N1—C2—C3	0.000 (2)	C4—C5—C6—N1	0.000 (3)
Ge1—N1—C2—C3	180.000 (2)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x, −y+1, −z+1; (iii) −x+1, y, z.