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ISSN: 2056-9890

Bis(cyclo­hexyl­ammonium) tetra­bromido­cuprate(II)

aOrdered Matter Science Research Center, College of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, People's Republic of China
*Correspondence e-mail: saltfish777@gmail.com

(Received 22 February 2012; accepted 14 March 2012; online 21 March 2012)

The structure of the title salt, (C6H14N)2[CuBr4], is built up from cyclo­hexyl­ammonium cations and tetra­bromidocuprate anions, the latter being located on an inversion center. In the crystal, anions and cations are inter­connected by N—H⋯Br hydrogen bonds, forming ribbons parallel to [0-11].

Related literature

For background to the development of ferroelectric pure organic or inorganic compounds, see: Haertling (1999[Haertling, G. H. (1999). J. Am. Ceram. Soc. 82, 797-818.]); Homes et al. (2001[Homes, C. C., Vogt, T., Shapiro, S. M., Wakimoto, S. & Ramirez, A. P. (2001). Science, 293, 673-676.]). For the synthesis of a variety of compounds with potential piezoelectric and ferroelectric properties, see: Fu et al. (2009[Fu, D.-W., Ge, J.-Z., Dai, J., Ye, H.-Y. & Qu, Z.-R. (2009). Inorg. Chem. Commun. 12, 994-997.]); Hang et al. (2009[Hang, T., Fu, D.-W., Ye, Q. & Xiong, R.-G. (2009). Cryst. Growth Des. 9, 2026-2029.]). For the synthesis of the title compound, see: Willett (2004[Willett, R. D. (2004). Inorg. Chem. 43, 3804-3811.]).

[Scheme 1]

Experimental

Crystal data
  • (C6H14N)2[CuBr4]

  • Mr = 583.51

  • Monoclinic, P 21 /c

  • a = 14.372 (3) Å

  • b = 7.6483 (15) Å

  • c = 9.1561 (18) Å

  • β = 106.89 (3)°

  • V = 963.0 (3) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 9.42 mm−1

  • T = 293 K

  • 0.33 × 0.28 × 0.20 mm

Data collection
  • Rigaku SCXmini diffractometer

  • Absorption correction: multi-scan (CrystalClear; Rigaku, 2005[Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.056, Tmax = 0.152

  • 9579 measured reflections

  • 2199 independent reflections

  • 1468 reflections with I > 2σ(I)

  • Rint = 0.092

  • 2 standard reflections every 150 reflections intensity decay: none

Refinement
  • R[F2 > 2σ(F2)] = 0.047

  • wR(F2) = 0.095

  • S = 1.03

  • 2199 reflections

  • 88 parameters

  • H-atom parameters constrained

  • Δρmax = 0.62 e Å−3

  • Δρmin = −0.77 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1D⋯Br2i 0.89 2.60 3.474 (4) 166
N1—H1C⋯Br2ii 0.89 2.56 3.445 (4) 174
N1—H1E⋯Br3iii 0.89 2.62 3.341 (4) 138
Symmetry codes: (i) x, y+1, z-1; (ii) [x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]; (iii) [x, -y+{\script{3\over 2}}, z-{\script{1\over 2}}].

Data collection: CrystalClear (Rigaku, 2005[Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.]); cell refinement: CrystalClear; data reduction: CrystalClear; 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: DIAMOND (Brandenburg, 1999[Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

At present, much attention in ferroelectric material field is focused on developing ferroelectric pure organic or inorganic compounds (Haertling, 1999; Homes et al. 2001). Recently we have reported the synthesis of a variety of compounds (Fu et al., 2009; Hang et al., 2009), which have potential piezoelectric and ferroelectric properties. In order to find more dielectric ferroelectric materials, we investigated the physical properties of the title compound (Fig. 1). The dielectric constant of the title compound as a function of temperature indicates that the permittivity is basically temperature-independent (dielectric constant equaling to 0.42 to 6.6), suggesting that this compound should be not a real ferroelectrics or that no phase transition occurs within the measured temperature range. Similarly, below the melting point (443 K) of the compound, the dielectric constant as a function of temperature also goes smoothly, and there is no dielectric anomaly observed. Herein, we report the synthesis and crystal structure of the title compound.

The structure of the title compound is shown in Fig. 1. There are one half CuBr42- anion and one cyclohexylammonium cation in the asymmetric unit. The cyclohexyl ring has the chair conformation. As it can be seen from the packing diagram (Fig. 2), ions are connected via intermolecular N—H···Br hydrogen bonds to form a one dimensional chain in the crystal. Dipole–dipole and van der Waals interactions are effective in the molecular packing.

Related literature top

For background to the development of ferroelectric pure organic or inorganic compounds, see: Haertling (1999); Homes et al. (2001). For the synthesis of a variety of compounds with potential piezoelectric and ferroelectric properties, see: Fu et al. (2009); Hang et al. (2009). For the synthesis of the title compound, see: Willett (2004).

Experimental top

Crystals of the title compound were grown by evaporation of an aqueous solution containing a 2:1 ratio of cyclohexylammonium bromide and copper(II) bromide. A few drops of hydrobromic acid were added to the solution to avoid hydrolysis of the Cu(II) ion (Willett, 2004).

Refinement top

H atoms were positioned geometrically and refined using a riding model, with C—H = 0.97–0.98 Å, N—H = 0.89 Å and with Uiso(H) = 1.2Ueq(C) or Uiso(H) = 1.5Ueq(N).

Structure description top

At present, much attention in ferroelectric material field is focused on developing ferroelectric pure organic or inorganic compounds (Haertling, 1999; Homes et al. 2001). Recently we have reported the synthesis of a variety of compounds (Fu et al., 2009; Hang et al., 2009), which have potential piezoelectric and ferroelectric properties. In order to find more dielectric ferroelectric materials, we investigated the physical properties of the title compound (Fig. 1). The dielectric constant of the title compound as a function of temperature indicates that the permittivity is basically temperature-independent (dielectric constant equaling to 0.42 to 6.6), suggesting that this compound should be not a real ferroelectrics or that no phase transition occurs within the measured temperature range. Similarly, below the melting point (443 K) of the compound, the dielectric constant as a function of temperature also goes smoothly, and there is no dielectric anomaly observed. Herein, we report the synthesis and crystal structure of the title compound.

The structure of the title compound is shown in Fig. 1. There are one half CuBr42- anion and one cyclohexylammonium cation in the asymmetric unit. The cyclohexyl ring has the chair conformation. As it can be seen from the packing diagram (Fig. 2), ions are connected via intermolecular N—H···Br hydrogen bonds to form a one dimensional chain in the crystal. Dipole–dipole and van der Waals interactions are effective in the molecular packing.

For background to the development of ferroelectric pure organic or inorganic compounds, see: Haertling (1999); Homes et al. (2001). For the synthesis of a variety of compounds with potential piezoelectric and ferroelectric properties, see: Fu et al. (2009); Hang et al. (2009). For the synthesis of the title compound, see: Willett (2004).

Computing details top

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Perspective structure of the title compound, with displacement ellipsoids drawn at the 30% probability level.
[Figure 2] Fig. 2. The crystal packing of the title compound viewed along the b axis showing the hydrogen bonds network. Some of the H atoms have been omitted for clarity.
Bis(cyclohexylammonium) tetrabromidocuprate(II) top
Crystal data top
(C6H14N)2[CuBr4]F(000) = 566
Mr = 583.51Dx = 2.012 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 2203 reflections
a = 14.372 (3) Åθ = 2.3–27.5°
b = 7.6483 (15) ŵ = 9.42 mm1
c = 9.1561 (18) ÅT = 293 K
β = 106.89 (3)°Block, sepia
V = 963.0 (3) Å30.33 × 0.28 × 0.20 mm
Z = 2
Data collection top
Rigaku SCXmini
diffractometer
1468 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.092
Graphite monochromatorθmax = 27.5°, θmin = 3.1°
ω scansh = 1818
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
k = 99
Tmin = 0.056, Tmax = 0.152l = 1111
9579 measured reflections2 standard reflections every 150 reflections
2199 independent reflections intensity decay: none
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)] = 0.047Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.095H-atom parameters constrained
S = 1.03 w = 1/[σ2(Fo2) + (0.024P)2]
where P = (Fo2 + 2Fc2)/3
2199 reflections(Δ/σ)max = 0.001
88 parametersΔρmax = 0.62 e Å3
0 restraintsΔρmin = 0.77 e Å3
0 constraints
Crystal data top
(C6H14N)2[CuBr4]V = 963.0 (3) Å3
Mr = 583.51Z = 2
Monoclinic, P21/cMo Kα radiation
a = 14.372 (3) ŵ = 9.42 mm1
b = 7.6483 (15) ÅT = 293 K
c = 9.1561 (18) Å0.33 × 0.28 × 0.20 mm
β = 106.89 (3)°
Data collection top
Rigaku SCXmini
diffractometer
1468 reflections with I > 2σ(I)
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
Rint = 0.092
Tmin = 0.056, Tmax = 0.1522 standard reflections every 150 reflections
9579 measured reflections intensity decay: none
2199 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0470 restraints
wR(F2) = 0.095H-atom parameters constrained
S = 1.03Δρmax = 0.62 e Å3
2199 reflectionsΔρmin = 0.77 e Å3
88 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cu10.00000.00001.00000.0342 (2)
Br20.17788 (4)0.00282 (7)1.09313 (6)0.03796 (18)
Br30.00212 (4)0.25662 (7)0.84636 (6)0.04466 (19)
N10.1634 (3)0.9201 (6)0.4590 (4)0.0399 (11)
H1E0.11130.97600.46900.060*
H1C0.16270.81000.48980.060*
H1D0.16270.92160.36150.060*
C10.4344 (4)1.0010 (7)0.6360 (6)0.0484 (16)
H1A0.43961.11860.59940.058*
H1B0.49050.93510.62820.058*
C20.4348 (5)1.0087 (7)0.8026 (6)0.0525 (17)
H2A0.43760.89090.84290.063*
H2B0.49231.07090.86180.063*
C30.3442 (4)1.1006 (8)0.8188 (6)0.0497 (16)
H3A0.34421.09600.92470.060*
H3B0.34591.22250.79060.060*
C40.2518 (4)1.0177 (7)0.7197 (5)0.0389 (14)
H4A0.19611.08570.72600.047*
H4B0.24530.90060.75630.047*
C50.2537 (4)1.0092 (6)0.5542 (5)0.0309 (12)
H5A0.25421.12900.51660.037*
C60.3421 (4)0.9158 (8)0.5364 (5)0.0400 (14)
H6A0.34190.91970.43040.048*
H6B0.34030.79410.56540.048*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.0304 (6)0.0312 (5)0.0383 (5)0.0027 (4)0.0055 (4)0.0048 (4)
Br20.0322 (4)0.0389 (3)0.0412 (3)0.0035 (3)0.0082 (3)0.0022 (2)
Br30.0428 (4)0.0384 (3)0.0463 (3)0.0101 (3)0.0026 (3)0.0103 (3)
N10.031 (3)0.046 (3)0.039 (2)0.005 (2)0.004 (2)0.006 (2)
C10.035 (4)0.066 (4)0.044 (3)0.004 (3)0.011 (3)0.008 (3)
C20.043 (4)0.066 (4)0.039 (3)0.001 (3)0.002 (3)0.001 (3)
C30.060 (5)0.052 (4)0.037 (3)0.008 (3)0.012 (3)0.015 (3)
C40.030 (4)0.048 (4)0.036 (3)0.004 (3)0.006 (3)0.004 (3)
C50.030 (3)0.029 (3)0.031 (3)0.001 (3)0.006 (2)0.001 (2)
C60.032 (4)0.058 (4)0.032 (3)0.002 (3)0.013 (3)0.005 (3)
Geometric parameters (Å, º) top
Cu1—Br3i2.4201 (6)C2—H2A0.9700
Cu1—Br32.4201 (6)C2—H2B0.9700
Cu1—Br22.4488 (9)C3—C41.513 (7)
Cu1—Br2i2.4488 (9)C3—H3A0.9700
N1—C51.500 (6)C3—H3B0.9700
N1—H1E0.8900C4—C51.525 (6)
N1—H1C0.8900C4—H4A0.9700
N1—H1D0.8900C4—H4B0.9700
C1—C61.521 (7)C5—C61.507 (7)
C1—C21.525 (6)C5—H5A0.9800
C1—H1A0.9700C6—H6A0.9700
C1—H1B0.9700C6—H6B0.9700
C2—C31.525 (7)
Br3i—Cu1—Br3180.0C4—C3—C2112.0 (4)
Br3i—Cu1—Br289.59 (3)C4—C3—H3A109.2
Br3—Cu1—Br290.41 (3)C2—C3—H3A109.2
Br3i—Cu1—Br2i90.41 (3)C4—C3—H3B109.2
Br3—Cu1—Br2i89.59 (3)C2—C3—H3B109.2
Br2—Cu1—Br2i180.000 (9)H3A—C3—H3B107.9
C5—N1—H1E109.5C3—C4—C5110.3 (5)
C5—N1—H1C109.5C3—C4—H4A109.6
H1E—N1—H1C109.5C5—C4—H4A109.6
C5—N1—H1D109.5C3—C4—H4B109.6
H1E—N1—H1D109.5C5—C4—H4B109.6
H1C—N1—H1D109.5H4A—C4—H4B108.1
C6—C1—C2111.4 (5)N1—C5—C6109.6 (4)
C6—C1—H1A109.3N1—C5—C4109.6 (4)
C2—C1—H1A109.3C6—C5—C4112.8 (4)
C6—C1—H1B109.3N1—C5—H5A108.3
C2—C1—H1B109.3C6—C5—H5A108.3
H1A—C1—H1B108.0C4—C5—H5A108.3
C3—C2—C1111.1 (5)C5—C6—C1110.4 (4)
C3—C2—H2A109.4C5—C6—H6A109.6
C1—C2—H2A109.4C1—C6—H6A109.6
C3—C2—H2B109.4C5—C6—H6B109.6
C1—C2—H2B109.4C1—C6—H6B109.6
H2A—C2—H2B108.0H6A—C6—H6B108.1
Symmetry code: (i) x, y, z+2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1D···Br2ii0.892.603.474 (4)166
N1—H1C···Br2iii0.892.563.445 (4)174
N1—H1E···Br3iv0.892.623.341 (4)138
Symmetry codes: (ii) x, y+1, z1; (iii) x, y+1/2, z1/2; (iv) x, y+3/2, z1/2.

Experimental details

Crystal data
Chemical formula(C6H14N)2[CuBr4]
Mr583.51
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)14.372 (3), 7.6483 (15), 9.1561 (18)
β (°) 106.89 (3)
V3)963.0 (3)
Z2
Radiation typeMo Kα
µ (mm1)9.42
Crystal size (mm)0.33 × 0.28 × 0.20
Data collection
DiffractometerRigaku SCXmini
Absorption correctionMulti-scan
(CrystalClear; Rigaku, 2005)
Tmin, Tmax0.056, 0.152
No. of measured, independent and
observed [I > 2σ(I)] reflections
9579, 2199, 1468
Rint0.092
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.047, 0.095, 1.03
No. of reflections2199
No. of parameters88
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.62, 0.77

Computer programs: CrystalClear (Rigaku, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 1999).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1D···Br2i0.892.603.474 (4)165.9
N1—H1C···Br2ii0.892.563.445 (4)174.4
N1—H1E···Br3iii0.892.623.341 (4)138.3
Symmetry codes: (i) x, y+1, z1; (ii) x, y+1/2, z1/2; (iii) x, y+3/2, z1/2.
 

Acknowledgements

The author is grateful to the starter fund of Southeast University for financial support to buy the X-ray diffractometer.

References

First citationBrandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationFu, D.-W., Ge, J.-Z., Dai, J., Ye, H.-Y. & Qu, Z.-R. (2009). Inorg. Chem. Commun. 12, 994–997.  Web of Science CSD CrossRef CAS Google Scholar
First citationHaertling, G. H. (1999). J. Am. Ceram. Soc. 82, 797–818.  CrossRef CAS Google Scholar
First citationHang, T., Fu, D.-W., Ye, Q. & Xiong, R.-G. (2009). Cryst. Growth Des. 9, 2026–2029.  Web of Science CSD CrossRef CAS Google Scholar
First citationHomes, C. C., Vogt, T., Shapiro, S. M., Wakimoto, S. & Ramirez, A. P. (2001). Science, 293, 673–676.  Web of Science CrossRef PubMed CAS Google Scholar
First citationRigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationWillett, R. D. (2004). Inorg. Chem. 43, 3804–3811.  Web of Science CSD CrossRef PubMed CAS Google Scholar

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ISSN: 2056-9890
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