Dibromidotris(dimethyl­amine)magnesium(II)

Vitze, H.; Lerner, H.-W.; Bolte, M.

doi:10.1107/S1600536809024702

metal-organic compounds

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Volume 65| Part 8| August 2009| Page m888

doi:10.1107/S1600536809024702

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Dibromidotris(dimethylamine)magnesium(II)

Hannes Vitze,^a Hans-Wolfram Lerner ^a and Michael Bolte ^a ^*

^aInstitut für Anorganische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt/Main, Germany
^*Correspondence e-mail: bolte@chemie.uni-frankfurt.de

(Received 24 June 2009; accepted 26 June 2009; online 8 July 2009)

The Mg centre in the title compound, [MgBr₂(C₂H₇N)₃], is pentacoordinated in a trigonal-bipyramidal mode with the two Br atoms in axial positions and the N atoms of the dimethylamine ligands in equatorial positions. The Mg^II centre is located on a crystallographic twofold rotation axis. The crystal structure is stabilized by N—H⋯Br hydrogen bonds. The N atom and H atoms of one dimethylamine ligand are disordered over two equally occupied positions.

Related literature

The solid-state structures of Mg–Br compounds feature coordination numbers of the Mg center from four as in [MgBr(Si^tBu₃)(THF)]₂ (Lerner et al., 2003 ) to six as in [MgBr₂(THF)₄] (Lorbach et al., 2007 ).

Experimental

Crystal data

[MgBr₂(C₂H₇N)₃]
M_r = 319.39
Hexagonal, P 3₂ 21
a = 9.0951 (7) Å
c = 14.4544 (12) Å
V = 1035.49 (14) Å³
Z = 3
Mo Kα radiation
μ = 5.88 mm⁻¹
T = 173 K
0.25 × 0.25 × 0.23 mm

Data collection

Stoe IPDSII two-circle diffractometer
Absorption correction: multi-scan (MULABS; Spek, 2003 ; Blessing, 1995 ) T_min = 0.321, T_max = 0.345 (expected range = 0.241–0.258)
5279 measured reflections
1285 independent reflections
1223 reflections with I > 2σ(I)
R_int = 0.037

Refinement

R[F² > 2σ(F²)] = 0.022
wR(F²) = 0.049
S = 0.96
1285 reflections
61 parameters
H-atom parameters constrained
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.34 e Å⁻³
Absolute structure: Flack (1983 ), 517 Friedel pairs
Flack parameter: −0.012 (17)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯Br1ⁱ	0.93	2.90	3.638 (2)	137
N2—H2⋯Br1ⁱⁱ	0.93	2.70	3.554 (5)	153
Symmetry codes: (i) $[-x+1, -x+y, -z+{\script{2\over 3}}]$ ; (ii) $[-x+y+1, -x+1, z+{\script{1\over 3}}]$ .

Data collection: X-AREA (Stoe & Cie, 2001 ); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 2008); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809024702/at2830sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809024702/at2830Isup2.hkl

checkCIF report

Comment top

The solid-state structures of Mg—Br compounds feature coordination numbers of the Mg center from four as in [MgBr(SitBu₃)(THF)]₂ (Lerner et al., 2003) to six as in [MgBr₂(THF)₄] (Lorbach et al., 2007). Most of the Mg—Br compounds possess an octahedral coordination sphere which surrounds the Mg cation whereas only a few compounds are found in the Cambridge Structural Database with four- and five-coordinated Mg centers. We report here the X-ray crystal structure analysis of [MgBr₂(NHMe₂)₃], the adduct of MgBr₂ with three dimethylamine molecules, which was obtained as a by-product from the reaction of C₆F₅MgBr with BrB(NMe₂) in Et₂O.

Related literature top

The solid-state structures of Mg–Br compounds feature coordination numbers of the Mg center from four as in [MgBr(Si^tBu₃)(THF)]₂ (Lerner et al., 2003) to six as in [MgBr₂(THF)₄] (Lorbach et al., 2007).

Experimental top

At 273 K, BrB(NMe₂) (3.5 g, 19.6 mmol) was added to a solution of C₆F₅MgBr in Et₂O which was obtained from C₆F₅Br (4,6 g, 18.6 mmol) and Mg (0.5 g, 21.0 mmol) in 25 ml Et₂O. After distillation of C₆F₅B(NMe₂) (yield 73%) colourless crystals of the title compound were obtained as distillation residue.

Computing details top

Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA (Stoe & Cie, 2001); data reduction: X-AREA (Stoe & Cie, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

Fig. 1. Perspective view of the title compound with the atom numbering scheme; displacement ellipsoids are at the 50% probability level; H atoms are drawn as small spheres of arbitrary radii. Only one of the two disordered moieties is shown.

Dibromidotris(dimethylamine)magnesium(II) top

Crystal data top

[MgBr₂(C₂H₇N)₃]	D_x = 1.537 Mg m⁻³
M_r = 319.39	Mo Kα radiation, λ = 0.71073 Å
Hexagonal, P3₂21	Cell parameters from 5127 reflections
Hall symbol: P 32 2"	θ = 3.8–25.6°
a = 9.0951 (7) Å	µ = 5.88 mm⁻¹
c = 14.4544 (12) Å	T = 173 K
V = 1035.49 (14) Å³	Block, colourless
Z = 3	0.25 × 0.25 × 0.23 mm
F(000) = 480

Data collection top

Stoe IPDSII two-circle diffractometer	1285 independent reflections
Radiation source: fine-focus sealed tube	1223 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.037
ω scans	θ_max = 25.6°, θ_min = 3.8°
Absorption correction: multi-scan (MULABS; Spek, 2003; Blessing, 1995)	h = −11→8
T_min = 0.321, T_max = 0.345	k = −7→11
5279 measured reflections	l = −17→17

Refinement top

Refinement on F²	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F² > 2σ(F²)] = 0.022	w = 1/[σ²(F_o²) + (0.0277P)² + 0.2606P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.049	(Δ/σ)_max = 0.001
S = 0.96	Δρ_max = 0.25 e Å⁻³
1285 reflections	Δρ_min = −0.34 e Å⁻³
61 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0106 (8)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 517 Friedel pairs
Secondary atom site location: difference Fourier map	Absolute structure parameter: −0.012 (17)

Crystal data top

[MgBr₂(C₂H₇N)₃]	Z = 3
M_r = 319.39	Mo Kα radiation
Hexagonal, P3₂21	µ = 5.88 mm⁻¹
a = 9.0951 (7) Å	T = 173 K
c = 14.4544 (12) Å	0.25 × 0.25 × 0.23 mm
V = 1035.49 (14) Å³

Data collection top

Stoe IPDSII two-circle diffractometer	1285 independent reflections
Absorption correction: multi-scan (MULABS; Spek, 2003; Blessing, 1995)	1223 reflections with I > 2σ(I)
T_min = 0.321, T_max = 0.345	R_int = 0.037
5279 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.022	H-atom parameters constrained
wR(F²) = 0.049	Δρ_max = 0.25 e Å⁻³
S = 0.96	Δρ_min = −0.34 e Å⁻³
1285 reflections	Absolute structure: Flack (1983), 517 Friedel pairs
61 parameters	Absolute structure parameter: −0.012 (17)
0 restraints

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	Occ. (<1)
Br1	0.39287 (4)	0.37977 (4)	0.318621 (17)	0.03405 (12)
Mg1	0.41479 (13)	0.41479 (13)	0.5000	0.0231 (3)
N1	0.4463 (3)	0.1927 (3)	0.50042 (15)	0.0301 (5)
H1	0.4887	0.1897	0.4423	0.036*
C1	0.5661 (5)	0.1872 (5)	0.5683 (2)	0.0441 (9)
H1A	0.6768	0.2910	0.5630	0.066*
H1B	0.5789	0.0883	0.5556	0.066*
H1C	0.5217	0.1787	0.6310	0.066*
C2	0.2791 (5)	0.0368 (4)	0.5070 (3)	0.0474 (9)
H2A	0.2012	0.0419	0.4620	0.071*
H2B	0.2334	0.0270	0.5695	0.071*
H2C	0.2916	−0.0621	0.4939	0.071*
N2	0.6685 (6)	0.6265 (6)	0.5188 (3)	0.0293 (12)	0.50
H2	0.7183	0.5896	0.5623	0.035*	0.50
C3	0.6750 (5)	0.7809 (4)	0.5616 (2)	0.0444 (8)
H3A	0.7933	0.8716	0.5684	0.067*	0.50
H3B	0.6206	0.7508	0.6226	0.067*	0.50
H3C	0.6143	0.8201	0.5218	0.067*	0.50
H3D	0.7715	0.8920	0.5457	0.067*	0.50
H3E	0.5785	0.7940	0.5803	0.067*	0.50
H3F	0.7063	0.7309	0.6125	0.067*	0.50

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.0453 (2)	0.04152 (19)	0.02015 (14)	0.02533 (16)	0.00289 (12)	−0.00057 (12)
Mg1	0.0233 (5)	0.0233 (5)	0.0200 (5)	0.0096 (6)	0.0012 (2)	−0.0012 (2)
N1	0.0368 (15)	0.0336 (14)	0.0232 (12)	0.0199 (12)	0.0007 (12)	−0.0026 (11)
C1	0.055 (2)	0.057 (2)	0.0385 (17)	0.041 (2)	−0.0087 (17)	−0.0075 (17)
C2	0.048 (2)	0.0276 (17)	0.057 (2)	0.0121 (16)	0.0043 (18)	−0.0044 (15)
N2	0.027 (2)	0.027 (3)	0.028 (3)	0.010 (2)	−0.0027 (19)	0.005 (2)
C3	0.054 (2)	0.0249 (16)	0.0425 (18)	0.0111 (16)	−0.0098 (17)	−0.0037 (14)

Geometric parameters (Å, º) top

Br1—Mg1	2.6365 (4)	C2—H2B	0.9800
Mg1—N2	2.159 (5)	C2—H2C	0.9800
Mg1—N2ⁱ	2.159 (5)	N2—N2ⁱ	0.856 (9)
Mg1—N1	2.177 (3)	N2—C3ⁱ	1.463 (6)
Mg1—N1ⁱ	2.177 (3)	N2—C3	1.508 (6)
Mg1—Br1ⁱ	2.6365 (4)	N2—H2	0.9300
N1—C2	1.475 (4)	C3—N2ⁱ	1.463 (6)
N1—C1	1.486 (4)	C3—H3A	0.9800
N1—H1	0.9300	C3—H3B	0.9800
C1—H1A	0.9800	C3—H3C	0.9800
C1—H1B	0.9800	C3—H3D	0.9788
C1—H1C	0.9800	C3—H3E	0.9803
C2—H2A	0.9800	C3—H3F	0.9780

N2—Mg1—N2ⁱ	22.9 (2)	C3ⁱ—N2—C3	110.5 (4)
N2—Mg1—N1	104.45 (16)	N2ⁱ—N2—Mg1	78.57 (12)
N2ⁱ—Mg1—N1	122.07 (17)	C3ⁱ—N2—Mg1	116.3 (3)
N2—Mg1—N1ⁱ	122.07 (17)	C3—N2—Mg1	114.1 (3)
N2ⁱ—Mg1—N1ⁱ	104.45 (16)	N2ⁱ—N2—H2	175.2
N1—Mg1—N1ⁱ	133.08 (16)	C3ⁱ—N2—H2	104.6
N2—Mg1—Br1ⁱ	88.69 (13)	C3—N2—H2	105.1
N2ⁱ—Mg1—Br1ⁱ	102.44 (14)	Mg1—N2—H2	105.0
N1—Mg1—Br1ⁱ	89.66 (6)	N2ⁱ—C3—H3A	119.2
N1ⁱ—Mg1—Br1ⁱ	85.86 (6)	N2—C3—H3A	109.9
N2—Mg1—Br1	102.44 (14)	N2ⁱ—C3—H3B	125.9
N2ⁱ—Mg1—Br1	88.69 (13)	N2—C3—H3B	109.2
N1—Mg1—Br1	85.86 (6)	H3A—C3—H3B	109.5
N1ⁱ—Mg1—Br1	89.66 (6)	N2ⁱ—C3—H3C	76.1
Br1ⁱ—Mg1—Br1	168.72 (5)	N2—C3—H3C	109.3
C2—N1—C1	110.2 (3)	H3A—C3—H3C	109.5
C2—N1—Mg1	110.0 (2)	H3B—C3—H3C	109.5
C1—N1—Mg1	118.2 (2)	N2ⁱ—C3—H3D	109.6
C2—N1—H1	105.9	N2—C3—H3D	117.5
C1—N1—H1	105.9	H3B—C3—H3D	124.5
Mg1—N1—H1	105.9	H3C—C3—H3D	82.1
N1—C1—H1A	109.5	N2ⁱ—C3—H3E	109.2
N1—C1—H1B	109.5	N2—C3—H3E	127.2
H1A—C1—H1B	109.5	H3A—C3—H3E	122.9
N1—C1—H1C	109.5	H3B—C3—H3E	55.2
H1A—C1—H1C	109.5	H3C—C3—H3E	54.3
H1B—C1—H1C	109.5	H3D—C3—H3E	109.5
N1—C2—H2A	109.5	N2ⁱ—C3—H3F	109.2
N1—C2—H2B	109.5	N2—C3—H3F	76.2
H2A—C2—H2B	109.5	H3A—C3—H3F	82.1
N1—C2—H2C	109.5	H3B—C3—H3F	54.4
H2A—C2—H2C	109.5	H3C—C3—H3F	163.4
H2B—C2—H2C	109.5	H3D—C3—H3F	109.7
N2ⁱ—N2—C3ⁱ	76.2 (6)	H3E—C3—H3F	109.6
N2ⁱ—N2—C3	70.4 (6)

N2—Mg1—N1—C2	168.6 (2)	Br1—Mg1—N2—N2ⁱ	54.3 (8)
N2ⁱ—Mg1—N1—C2	−175.4 (2)	N2ⁱ—Mg1—N2—C3ⁱ	−68.2 (7)
N1ⁱ—Mg1—N1—C2	−3.95 (19)	N1—Mg1—N2—C3ⁱ	75.0 (3)
Br1ⁱ—Mg1—N1—C2	80.0 (2)	N1ⁱ—Mg1—N2—C3ⁱ	−111.4 (3)
Br1—Mg1—N1—C2	−89.6 (2)	Br1ⁱ—Mg1—N2—C3ⁱ	164.3 (3)
N2—Mg1—N1—C1	40.9 (3)	Br1—Mg1—N2—C3ⁱ	−13.9 (4)
N2ⁱ—Mg1—N1—C1	56.8 (3)	N2ⁱ—Mg1—N2—C3	62.2 (7)
N1ⁱ—Mg1—N1—C1	−131.7 (2)	N1—Mg1—N2—C3	−154.6 (3)
Br1ⁱ—Mg1—N1—C1	−47.7 (2)	N1ⁱ—Mg1—N2—C3	19.0 (4)
Br1—Mg1—N1—C1	142.7 (2)	Br1ⁱ—Mg1—N2—C3	−65.3 (3)
N1—Mg1—N2—N2ⁱ	143.2 (7)	Br1—Mg1—N2—C3	116.5 (3)
N1ⁱ—Mg1—N2—N2ⁱ	−43.2 (8)	C3ⁱ—N2—C3—N2ⁱ	66.2 (5)
Br1ⁱ—Mg1—N2—N2ⁱ	−127.5 (7)	Mg1—N2—C3—N2ⁱ	−67.0 (4)

Symmetry code: (i) y, x, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Br1ⁱⁱ	0.93	2.90	3.638 (2)	137
N2—H2···Br1ⁱⁱⁱ	0.93	2.70	3.554 (5)	153

Symmetry codes: (ii) −x+1, −x+y, −z+2/3; (iii) −x+y+1, −x+1, z+1/3.

Experimental details

Crystal data
Chemical formula	[MgBr₂(C₂H₇N)₃]
M_r	319.39
Crystal system, space group	Hexagonal, P3₂21
Temperature (K)	173
a, c (Å)	9.0951 (7), 14.4544 (12)
V (Å³)	1035.49 (14)
Z	3
Radiation type	Mo Kα
µ (mm⁻¹)	5.88
Crystal size (mm)	0.25 × 0.25 × 0.23

Data collection
Diffractometer	Stoe IPDSII two-circle diffractometer
Absorption correction	Multi-scan (MULABS; Spek, 2003; Blessing, 1995)
T_min, T_max	0.321, 0.345
No. of measured, independent and observed [I > 2σ(I)] reflections	5279, 1285, 1223
R_int	0.037
(sin θ/λ)_max (Å⁻¹)	0.608

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.022, 0.049, 0.96
No. of reflections	1285
No. of parameters	61
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.25, −0.34
Absolute structure	Flack (1983), 517 Friedel pairs
Absolute structure parameter	−0.012 (17)

Computer programs: X-AREA (Stoe & Cie, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL-Plus (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Br1ⁱ	0.93	2.90	3.638 (2)	137.2
N2—H2···Br1ⁱⁱ	0.93	2.70	3.554 (5)	153.3

Symmetry codes: (i) −x+1, −x+y, −z+2/3; (ii) −x+y+1, −x+1, z+1/3.

References

Blessing, R. H. (1995). Acta Cryst. A51, 33–38. CrossRef CAS Web of Science IUCr Journals Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Lerner, H.-W., Scholz, S., Bolte, M., Wiberg, N., Nöth, H. & Krossing, I. (2003). Eur. J. Inorg. Chem. pp. 666–670. CSD CrossRef Google Scholar
Lorbach, A., Lerner, H.-W. & Bolte, M. (2007). Acta Cryst. C63, m174–m176. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Web of Science CrossRef CAS IUCr Journals Google Scholar
Stoe & Cie (2001). X-AREA. Stoe & Cie, Darmstadt, Germany. Google Scholar

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CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 65| Part 8| August 2009| Page m888

doi:10.1107/S1600536809024702

Open

access