organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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1-Bromo­methyl-4-aza-1-azoniabi­cyclo­[2.2.2]octane bromide

aUniversity of Illinois, School of Chemical Sciences, Box 77-5, 600 South Mathews Avenue, Urbana, Illinois 61801, USA, bUniversity of Illinois, School of Chemical Sciences, Box 59-1, 505 South Mathews Avenue, Urbana, Illinois 61801, USA, and cUniversity of Illinois, School of Chemical Sciences, Box 55-5, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
*Correspondence e-mail: jsmoore@illinois.edu

(Received 19 December 2009; accepted 4 January 2010; online 16 January 2010)

The title compound, C7H14BrN2+·Br, was prepared by nucleophilic substitution of DABCO (systematic name: 1,4-diaza­bicyclo­[2.2.2]octa­ne) with dibromo­methane in acetone. The structure features Br⋯H close contacts (2.79 and 2.90 Å) as well as a weak bromine–bromide inter­action [3.6625 (6) Å].

Related literature

For use of DABCO as an organocatalyst, see Basaviah et al. (2003[Basaviah, D., Rao, A. J. & Satyanarayana, T. (2003). Chem. Rev. 103, 811-891.]). For related haloalkyl­ations of DABCO, see: Almarzoqi et al. (1986[Almarzoqi, B., George, A. V. & Isaacs, N. S. (1986). Tetrahedron Lett. 42, 601-607.]); Fronczek et al. (1990[Fronczek, F. R., Ivie, M. L. & Maverick, A. W. (1990). Acta Cryst. C46, 2057-2062.]); Gustafsson et al. (2005[Gustafsson, B., Håkansson, M. & Jagner, S. (2005). Inorg. Chim. Acta, 358, 1309-1312.]); Banks et al. (1993[Banks, R. E., Sharif, I. & Pritchard, R. G. (1993). Acta Cryst. C49, 492-495.]); Batsanov et al. (2005[Batsanov, A. S., Trmcic, J. & Sandford, G. (2005). Acta Cryst. E61, o681-o682.]); Fletcher Claville et al. (2007[Fletcher Claville, M. O., Payne, R. J., Parker, B. C. & Fronczek, F. R. (2007). Acta Cryst. E63, o2601.]). For inversion twinning, see: Flack & Bernardinelli (2000[Flack, H. D. & Bernardinelli, G. (2000). J. Appl. Cryst. 33, 1143-1148.]).

[Scheme 1]

Experimental

Crystal data
  • C7H14BrN2+·Br

  • Mr = 286.02

  • Orthorhombic, C m c 21

  • a = 7.1100 (3) Å

  • b = 11.8085 (5) Å

  • c = 11.7702 (5) Å

  • V = 988.21 (7) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 8.15 mm−1

  • T = 193 K

  • 0.36 × 0.35 × 0.06 mm

Data collection
  • Bruker Kappa APEXII CCD diffractometer

  • Absorption correction: integration [SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) and XPREP (Bruker, 2005[Bruker (2005). SAINT, XCIF and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.])] Tmin = 0.151, Tmax = 0.744

  • 7347 measured reflections

  • 991 independent reflections

  • 954 reflections with I > 2σ(I)

  • Rint = 0.050

Refinement
  • R[F2 > 2σ(F2)] = 0.022

  • wR(F2) = 0.052

  • S = 1.10

  • 991 reflections

  • 61 parameters

  • 1 restraint

  • H-atom parameters constrained

  • Δρmax = 0.42 e Å−3

  • Δρmin = −0.44 e Å−3

  • Absolute structure: Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]), 468 Friedel pairs

  • Flack parameter: −0.004 (17)

Data collection: APEX2 (Bruker, 2004[Bruker (2004). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2005[Bruker (2005). SAINT, XCIF and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT and XPREP (Bruker, 2005[Bruker (2005). SAINT, XCIF and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) and CrystalMaker (CrystalMaker, 1994[CrystalMaker (1994). CrystalMaker. CrystalMaker Software Ltd, Oxford, England. www.CrystalMaker.com.]); software used to prepare material for publication: XCIF (Bruker, 2005[Bruker (2005). SAINT, XCIF and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.]).

Supporting information


Comment top

The nucleophilicity of 1,4-diazabicyclo[2.2.2]octane (DABCO) has enabled it to be an excellent organocatalyst for a variety of reactions, in particular the Baylis-Hillman reaction (Basaviah et al., 2003). Furthermore, DABCO can undergo substitution with even relatively unreactive electrophiles such as dichloromethane (Almarzoqi et al., 1986).

We have isolated crystals of the title compound of sufficient quality for crystallographic analysis. Typically, the reaction between dibromomethane and DABCO proceeds quickly in acetone, resulting in the immediate precipitation of the monoalkylated bromide salt that is insoluble in acetone. However, at sufficiently low concentrations of reactants, slow crystallization of the product occurs.

The title molecule crystallizes in a non-centrosymmetric space group, Cmc21. One notable feature of this structure is a close contact between free bromide and the bromomethyl hydrogen (Br2···H5A) of 2.794 (3) Å. Another close contact for H4B···Br2 (2.899 (3) Å) was found. There is also a relatively close contact between the covalently-bound bromine and bromide anion (Br1···Br2 3.6625 (6) Å). However, this distance is significantly longer than the Br···Br interaction seen in a related structure, (bromomethyl)trimethylammonium bromide (Br···Br = 3.369 Å) (Fletcher Claville et al. 2007).

Related literature top

For use of DABCO as an organocatalyst, see Basaviah et al. (2003). For related haloalkylations of DABCO, see: Almarzoqi et al. (1986); Fronczek et al. (1990); Gustafsson et al. (2005); Banks et al. (1993); Batsanov et al. (2005); Fletcher Claville et al. (2007). For inversion twinning, see: Flack & Bernardinelli (2000).

Experimental top

Dibromomethane (10 mmol) was added to a solution of DABCO (10 mmol) in acetone (100 ml). Colorless plates of poor quality evolve almost immediately, which after 1 h are filtered. The filtrate is sealed in a flask and left to sit for 1 week, after which prisms suitable for X-ray analysis form on the side of the flask.

Refinement top

A structural model consisting of one symmetrically independent molecule was developed. All non-hydrogen atoms were refined with anisotropic displacement parameters. All hydrogen atoms were placed in ideal positions and refined as riding atoms. The ideally calculated H atoms on C1, C2, and C5 are related by the symmetry operation (1 - x, y, z). For these H atoms the special position constraints were suppressed to allow for the correct calculation of the idealized H atom positions. For all H atoms the Uiso values were assigned as 1.2 times the carrier Ueq. On the basis of 468 unmerged Friedel opposites, the likelihood of inversion twinning is negligible (Flack, 1983; Flack& Bernardinelli, 2000).

Structure description top

The nucleophilicity of 1,4-diazabicyclo[2.2.2]octane (DABCO) has enabled it to be an excellent organocatalyst for a variety of reactions, in particular the Baylis-Hillman reaction (Basaviah et al., 2003). Furthermore, DABCO can undergo substitution with even relatively unreactive electrophiles such as dichloromethane (Almarzoqi et al., 1986).

We have isolated crystals of the title compound of sufficient quality for crystallographic analysis. Typically, the reaction between dibromomethane and DABCO proceeds quickly in acetone, resulting in the immediate precipitation of the monoalkylated bromide salt that is insoluble in acetone. However, at sufficiently low concentrations of reactants, slow crystallization of the product occurs.

The title molecule crystallizes in a non-centrosymmetric space group, Cmc21. One notable feature of this structure is a close contact between free bromide and the bromomethyl hydrogen (Br2···H5A) of 2.794 (3) Å. Another close contact for H4B···Br2 (2.899 (3) Å) was found. There is also a relatively close contact between the covalently-bound bromine and bromide anion (Br1···Br2 3.6625 (6) Å). However, this distance is significantly longer than the Br···Br interaction seen in a related structure, (bromomethyl)trimethylammonium bromide (Br···Br = 3.369 Å) (Fletcher Claville et al. 2007).

For use of DABCO as an organocatalyst, see Basaviah et al. (2003). For related haloalkylations of DABCO, see: Almarzoqi et al. (1986); Fronczek et al. (1990); Gustafsson et al. (2005); Banks et al. (1993); Batsanov et al. (2005); Fletcher Claville et al. (2007). For inversion twinning, see: Flack & Bernardinelli (2000).

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT and XPREP (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and CrystalMaker (CrystalMaker, 1994); software used to prepare material for publication: XCIF (Bruker, 2005).

Figures top
[Figure 1] Fig. 1. Thermal ellipsoid plot showing non-H atoms at 35% probability and H atoms as arbitrary small spheres. The atoms labeled A are related by the symmetry operator (1 - x, y, z).
[Figure 2] Fig. 2. A packing plot of the unit cell as viewed down the a-axis showing 35% probability ellipsoids for non-H atoms. H atoms have been removed to improve clarity.
1-Bromomethyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide top
Crystal data top
C7H14BrN2+·BrF(000) = 560
Mr = 286.02Dx = 1.922 Mg m3
Orthorhombic, Cmc21Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2c -2Cell parameters from 3160 reflections
a = 7.1100 (3) Åθ = 3.3–26.3°
b = 11.8085 (5) ŵ = 8.15 mm1
c = 11.7702 (5) ÅT = 193 K
V = 988.21 (7) Å3Plate, colourless
Z = 40.36 × 0.35 × 0.06 mm
Data collection top
Bruker Kappa APEXII CCD
diffractometer
991 independent reflections
Radiation source: fine-focus sealed tube954 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.050
φ and ω scansθmax = 25.4°, θmin = 3.3°
Absorption correction: integration
(SHELXTL and XPREP; Bruker, 2005)
h = 88
Tmin = 0.151, Tmax = 0.744k = 1414
7347 measured reflectionsl = 1414
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.022H-atom parameters constrained
wR(F2) = 0.052 w = 1/[σ2(Fo2) + (0.0248P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.10(Δ/σ)max < 0.001
991 reflectionsΔρmax = 0.42 e Å3
61 parametersΔρmin = 0.44 e Å3
1 restraintAbsolute structure: Flack (1983), 468 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.004 (17)
Crystal data top
C7H14BrN2+·BrV = 988.21 (7) Å3
Mr = 286.02Z = 4
Orthorhombic, Cmc21Mo Kα radiation
a = 7.1100 (3) ŵ = 8.15 mm1
b = 11.8085 (5) ÅT = 193 K
c = 11.7702 (5) Å0.36 × 0.35 × 0.06 mm
Data collection top
Bruker Kappa APEXII CCD
diffractometer
991 independent reflections
Absorption correction: integration
(SHELXTL and XPREP; Bruker, 2005)
954 reflections with I > 2σ(I)
Tmin = 0.151, Tmax = 0.744Rint = 0.050
7347 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.022H-atom parameters constrained
wR(F2) = 0.052Δρmax = 0.42 e Å3
S = 1.10Δρmin = 0.44 e Å3
991 reflectionsAbsolute structure: Flack (1983), 468 Friedel pairs
61 parametersAbsolute structure parameter: 0.004 (17)
1 restraint
Special details top

Experimental. One distinct cell was identified using APEX2 (Bruker, 2004). Seven frame series were integrated and filtered for statistical outliers using SAINT (Bruker, 2005) then corrected for absorption by integration using SHELXTL/XPREP V2005/2 (Bruker, 2005) before using SAINT/SADABS (Bruker, 2005) to sort, merge, and scale the combined data. No decay correction was applied.

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. Structure was phased by direct methods (Sheldrick, 2008). Systematic conditions suggested the ambiguous space group. The space group choice was confirmed by successful convergence of the full-matrix least-squares refinement on F2. The highest peaks in the final difference Fourier map were in the vicinity of atoms Br1 and Br2; the final map had no other significant features. A final analysis of variance between observed and calculated structure factors showed some dependence on amplitude and resolution.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Br10.50000.14054 (4)0.05638 (4)0.03174 (19)
Br20.00000.65245 (4)0.34152 (3)0.02920 (17)
N10.50000.5040 (4)0.1977 (4)0.0281 (9)
N20.50000.3707 (3)0.0253 (3)0.0188 (8)
C10.50000.5692 (5)0.0917 (5)0.0360 (13)
H1A0.61260.61850.08980.043*0.50
H1B0.38740.61850.08980.043*0.50
C20.50000.4932 (4)0.0128 (4)0.0291 (12)
H2A0.38710.50860.05950.035*0.50
H2B0.61290.50860.05950.035*0.50
C30.3326 (5)0.4320 (3)0.1979 (3)0.0369 (9)
H3A0.21890.48040.19600.044*
H3B0.32940.38750.26910.044*
C40.3283 (5)0.3507 (3)0.0964 (3)0.0264 (8)
H4A0.32630.27140.12360.032*
H4B0.21370.36400.05060.032*
C50.50000.3026 (4)0.0825 (4)0.0234 (10)
H5A0.61250.32290.12780.028*0.50
H5B0.38750.32290.12780.028*0.50
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0285 (4)0.0282 (3)0.0385 (4)0.0000.0000.0120 (3)
Br20.0230 (3)0.0325 (3)0.0321 (4)0.0000.0000.0042 (3)
N10.037 (2)0.027 (2)0.021 (2)0.0000.0000.0071 (18)
N20.021 (2)0.023 (2)0.013 (2)0.0000.0000.0006 (16)
C10.046 (3)0.024 (3)0.038 (3)0.0000.0000.005 (2)
C20.042 (3)0.023 (3)0.022 (3)0.0000.0000.006 (2)
C30.039 (2)0.037 (2)0.034 (2)0.0058 (18)0.0135 (16)0.0103 (18)
C40.0189 (18)0.035 (2)0.0254 (17)0.0029 (15)0.0062 (12)0.0040 (13)
C50.032 (3)0.025 (2)0.013 (2)0.0000.0000.0048 (18)
Geometric parameters (Å, º) top
Br1—C51.938 (5)C3—C41.532 (4)
N1—C3i1.463 (4)C3—H3A0.9900
N1—C31.464 (4)C3—H3B0.9900
N1—C11.466 (6)C4—H4A0.9900
N2—C41.499 (4)C4—H4B0.9900
N2—C4i1.499 (4)C5—H5A0.9900
N2—C51.502 (6)C5—H5B0.9900
N2—C21.514 (6)Br1—Br2ii3.6625 (6)
C1—C21.522 (7)Br2—H5Aiii2.79
C1—H1A0.9900Br2—H5Biv2.79
C1—H1B0.9900Br2—H4Bv2.90
C2—H2A0.9900Br2—H4Biv2.90
C2—H2B0.9900
C3i—N1—C3108.9 (4)H2A—C2—H2B108.3
C3i—N1—C1107.8 (3)N1—C3—C4112.3 (3)
C3—N1—C1107.8 (3)N1—C3—H3A109.1
C4—N2—C4i109.1 (4)C4—C3—H3A109.1
C4—N2—C5112.8 (2)N1—C3—H3B109.1
C4i—N2—C5112.8 (2)C4—C3—H3B109.1
C4—N2—C2108.4 (2)H3A—C3—H3B107.9
C4i—N2—C2108.4 (2)N2—C4—C3108.7 (3)
C5—N2—C2105.2 (3)N2—C4—H4A109.9
N1—C1—C2112.2 (4)C3—C4—H4A109.9
N1—C1—H1A109.2N2—C4—H4B109.9
C2—C1—H1A109.2C3—C4—H4B109.9
N1—C1—H1B109.2H4A—C4—H4B108.3
C2—C1—H1B109.2N2—C5—Br1113.2 (3)
H1A—C1—H1B107.9N2—C5—H5A108.9
N2—C2—C1108.9 (4)Br1—C5—H5A108.9
N2—C2—H2A109.9N2—C5—H5B108.9
C1—C2—H2A109.9Br1—C5—H5B108.9
N2—C2—H2B109.9H5A—C5—H5B107.7
C1—C2—H2B109.9
C3i—N1—C1—C258.7 (2)C4i—N2—C4—C359.3 (4)
C3—N1—C1—C258.7 (2)C5—N2—C4—C3174.6 (3)
C4—N2—C2—C159.1 (2)C2—N2—C4—C358.6 (3)
C4i—N2—C2—C159.1 (2)N1—C3—C4—N20.5 (4)
C5—N2—C2—C1180.0C4—N2—C5—Br162.1 (2)
N1—C1—C2—N20.0C4i—N2—C5—Br162.1 (2)
C3i—N1—C3—C457.5 (5)C2—N2—C5—Br1180.0
C1—N1—C3—C459.2 (4)
Symmetry codes: (i) x+1, y, z; (ii) x+1/2, y+1/2, z1/2; (iii) x+1, y+1, z+1/2; (iv) x, y+1, z+1/2; (v) x, y+1, z+1/2.

Experimental details

Crystal data
Chemical formulaC7H14BrN2+·Br
Mr286.02
Crystal system, space groupOrthorhombic, Cmc21
Temperature (K)193
a, b, c (Å)7.1100 (3), 11.8085 (5), 11.7702 (5)
V3)988.21 (7)
Z4
Radiation typeMo Kα
µ (mm1)8.15
Crystal size (mm)0.36 × 0.35 × 0.06
Data collection
DiffractometerBruker Kappa APEXII CCD
Absorption correctionIntegration
(SHELXTL and XPREP; Bruker, 2005)
Tmin, Tmax0.151, 0.744
No. of measured, independent and
observed [I > 2σ(I)] reflections
7347, 991, 954
Rint0.050
(sin θ/λ)max1)0.603
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.022, 0.052, 1.10
No. of reflections991
No. of parameters61
No. of restraints1
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.42, 0.44
Absolute structureFlack (1983), 468 Friedel pairs
Absolute structure parameter0.004 (17)

Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2005), SAINT and XPREP (Bruker, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and CrystalMaker (CrystalMaker, 1994), XCIF (Bruker, 2005).

 

Acknowledgements

This work was supported by the National Science Foundation under NSF Award Nos. CBET-0730667 and CHE-0642413. The Materials Chemistry Laboratory at the University of Illinois was supported in part by grants NSF CHE 95–03145 and NSF CHE 03–43032 from the National Science Foundation.

References

First citationAlmarzoqi, B., George, A. V. & Isaacs, N. S. (1986). Tetrahedron Lett. 42, 601–607.  CrossRef CAS Google Scholar
First citationBanks, R. E., Sharif, I. & Pritchard, R. G. (1993). Acta Cryst. C49, 492–495.  CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationBasaviah, D., Rao, A. J. & Satyanarayana, T. (2003). Chem. Rev. 103, 811–891.  Web of Science PubMed Google Scholar
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First citationFlack, H. D. & Bernardinelli, G. (2000). J. Appl. Cryst. 33, 1143–1148.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationFletcher Claville, M. O., Payne, R. J., Parker, B. C. & Fronczek, F. R. (2007). Acta Cryst. E63, o2601.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationFronczek, F. R., Ivie, M. L. & Maverick, A. W. (1990). Acta Cryst. C46, 2057–2062.  CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationGustafsson, B., Håkansson, M. & Jagner, S. (2005). Inorg. Chim. Acta, 358, 1309–1312.  Web of Science CSD CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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