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In the structure of the title compound, [CuBr(C6H8N2)]n, each Cu2+ cation is surrounded by two 2,3-dimethylpyrazine ligands and two Br- anions in a distorted tetrahedral arrangement. The Cu2+ cations and Br- anions form (Cu2Br2)2 rhomboid dimers located around a centre of inversion. The 2,3-dimethylpyrazine ligands connect the Cu2+ cations in the dimers into sheets parallel to (010).
Supporting information
CCDC reference: 163889
Data collection: DIF4 (Stoe & Cie, 1992); cell refinement: DIF4; data reduction: REDU4 (Stoe & Cie, 1992); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL/PC (Siemens, 1990); software used to prepare material for publication: CIFTAB in SHELXL97.
Poly[copper(I)-µ-bromo-µ-2,3-dimethylpyrazine-N:
N']
top
Crystal data top
[CuBr(C6H8N2)] | Dx = 2.231 Mg m−3 |
Mr = 251.59 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, Pbca | Cell parameters from 140 reflections |
a = 11.459 (2) Å | θ = 12–18.5° |
b = 9.7078 (11) Å | µ = 8.17 mm−1 |
c = 13.468 (4) Å | T = 293 K |
V = 1498.2 (6) Å3 | Irregular polyhedron, orange |
Z = 8 | 0.12 × 0.1 × 0.08 mm |
F(000) = 976 | |
Data collection top
Phillips PW-1100 four-circle diffractometer | 1681 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.031 |
Graphite monochromator | θmax = 30.0°, θmin = 3.0° |
ω–θ scans | h = −16→1 |
Absorption correction: numerical (X-SHAPE (Stoe & Cie, 1998) | k = −13→1 |
Tmin = 0.386, Tmax = 0.520 | l = −1→18 |
2821 measured reflections | 4 standard reflections every 120 min |
2186 independent reflections | intensity decay: none |
Refinement top
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)] = 0.032 | H-atom parameters constrained |
wR(F2) = 0.085 | w = 1/[σ2(Fo2) + (0.0467P)2 + 0.6968P] where P = (Fo2 + 2Fc2)/3 |
S = 1.05 | (Δ/σ)max = 0.001 |
2186 reflections | Δρmax = 0.72 e Å−3 |
94 parameters | Δρmin = −0.87 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0036 (4) |
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 | Uiso*/Ueq | |
Cu1 | 0.46639 (3) | 0.57377 (4) | 0.60884 (3) | 0.03019 (13) | |
Br1 | 0.50724 (3) | 0.68412 (3) | 0.44811 (2) | 0.02844 (11) | |
N1 | 0.6050 (2) | 0.5955 (2) | 0.70725 (17) | 0.0201 (5) | |
C1 | 0.6095 (2) | 0.5307 (3) | 0.7951 (2) | 0.0192 (5) | |
C2 | 0.7088 (2) | 0.5406 (3) | 0.8561 (2) | 0.0216 (5) | |
N2 | 0.8046 (2) | 0.6080 (3) | 0.82603 (18) | 0.0222 (5) | |
C3 | 0.7977 (2) | 0.6744 (3) | 0.7382 (2) | 0.0241 (6) | |
H3 | 0.8618 | 0.7242 | 0.7158 | 0.029* | |
C4 | 0.6988 (2) | 0.6702 (3) | 0.6812 (2) | 0.0233 (6) | |
H4 | 0.6965 | 0.7208 | 0.6225 | 0.028* | |
C5 | 0.5068 (3) | 0.4461 (3) | 0.8250 (2) | 0.0278 (6) | |
H5A | 0.4592 | 0.4977 | 0.8704 | 0.042* | |
H5B | 0.5333 | 0.3632 | 0.8568 | 0.042* | |
H5C | 0.4619 | 0.4229 | 0.7672 | 0.042* | |
C6 | 0.7101 (3) | 0.4799 (4) | 0.9578 (2) | 0.0367 (8) | |
H6A | 0.7739 | 0.5181 | 0.9949 | 0.055* | |
H6B | 0.7193 | 0.3818 | 0.9531 | 0.055* | |
H6C | 0.6380 | 0.5007 | 0.9907 | 0.055* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cu1 | 0.0243 (2) | 0.0399 (2) | 0.0264 (2) | −0.00295 (16) | −0.00025 (14) | 0.00090 (17) |
Br1 | 0.0405 (2) | 0.02242 (16) | 0.02244 (16) | 0.00252 (12) | −0.00023 (11) | 0.00262 (11) |
N1 | 0.0193 (10) | 0.0217 (11) | 0.0193 (10) | −0.0010 (9) | −0.0025 (8) | 0.0012 (9) |
C1 | 0.0190 (12) | 0.0170 (12) | 0.0217 (12) | 0.0023 (10) | 0.0027 (10) | 0.0019 (10) |
C2 | 0.0194 (13) | 0.0246 (13) | 0.0208 (12) | 0.0025 (11) | 0.0013 (9) | 0.0010 (11) |
N2 | 0.0163 (11) | 0.0282 (12) | 0.0221 (11) | −0.0002 (9) | 0.0003 (8) | 0.0009 (10) |
C3 | 0.0219 (13) | 0.0269 (14) | 0.0235 (13) | −0.0052 (11) | 0.0023 (10) | 0.0037 (12) |
C4 | 0.0257 (14) | 0.0245 (13) | 0.0197 (12) | −0.0022 (11) | −0.0001 (10) | 0.0047 (11) |
C5 | 0.0234 (13) | 0.0291 (14) | 0.0309 (14) | −0.0041 (11) | 0.0028 (12) | 0.0071 (13) |
C6 | 0.0268 (15) | 0.060 (2) | 0.0234 (15) | −0.0011 (16) | 0.0003 (11) | 0.0159 (15) |
Geometric parameters (Å, º) top
Cu1—N2i | 2.077 (2) | N2—C3 | 1.349 (4) |
Cu1—N1 | 2.080 (2) | N2—Cu1iii | 2.077 (2) |
Cu1—Br1 | 2.4602 (7) | C3—C4 | 1.370 (4) |
Cu1—Br1ii | 2.6358 (6) | C3—H3 | 0.93 |
Br1—Cu1ii | 2.6358 (6) | C4—H4 | 0.93 |
N1—C1 | 1.341 (3) | C5—H5A | 0.96 |
N1—C4 | 1.343 (4) | C5—H5B | 0.96 |
C1—C2 | 1.407 (4) | C5—H5C | 0.96 |
C1—C5 | 1.491 (4) | C6—H6A | 0.96 |
C2—N2 | 1.341 (4) | C6—H6B | 0.96 |
C2—C6 | 1.491 (4) | C6—H6C | 0.96 |
| | | |
N2i—Cu1—N1 | 113.34 (10) | N2—C3—C4 | 121.8 (3) |
N2i—Cu1—Br1 | 118.14 (7) | N2—C3—H3 | 119.1 |
N1—Cu1—Br1 | 111.79 (7) | C4—C3—H3 | 119.1 |
N2i—Cu1—Br1ii | 112.15 (7) | N1—C4—C3 | 122.1 (3) |
N1—Cu1—Br1ii | 101.21 (7) | N1—C4—H4 | 119 |
Br1—Cu1—Br1ii | 97.80 (2) | C3—C4—H4 | 119 |
Cu1—Br1—Cu1ii | 82.20 (2) | C1—C5—H5A | 110 |
C1—N1—C4 | 117.0 (2) | C1—C5—H5B | 110 |
C1—N1—Cu1 | 122.95 (18) | H5A—C5—H5B | 110 |
C4—N1—Cu1 | 119.96 (19) | C1—C5—H5C | 110 |
N1—C1—C2 | 121.0 (2) | H5A—C5—H5C | 110 |
N1—C1—C5 | 117.8 (2) | H5B—C5—H5C | 110 |
C2—C1—C5 | 121.2 (2) | C2—C6—H6A | 110 |
N2—C2—C1 | 121.3 (3) | C2—C6—H6B | 110 |
N2—C2—C6 | 117.5 (3) | H6A—C6—H6B | 110 |
C1—C2—C6 | 121.2 (3) | C2—C6—H6C | 110 |
C2—N2—C3 | 116.7 (2) | H6A—C6—H6C | 110 |
C2—N2—Cu1iii | 121.68 (19) | H6B—C6—H6C | 110 |
C3—N2—Cu1iii | 119.93 (19) | | |
Symmetry codes: (i) x−1/2, y, −z+3/2; (ii) −x+1, −y+1, −z+1; (iii) x+1/2, y, −z+3/2. |
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