metal-organic compounds
Bis[2,6-bis(2-methoxyphenyl)pyridinium] di-μ-bromido-bis[dibromidocuprate(II)]
aDepartment of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand, and bNational Metal and Materials Technology Center, Thailand Science Park, Klong Luang, Pathumthani, Thailand
*Correspondence e-mail: scpsf@mahidol.ac.th
The title salt, (C19H18NO2)2[Cu2Br6], was obtained from an attempt to synthesize the copper(II) complex of 2,6-bis(2-methoxyphenyl)pyridine (L) from a reaction between CuBr2 and one equivalent of L in CH2Cl2 at room temperature. The resulting compound is the salt of the 2,6-bis(2-methoxyphenyl)pyridinium cation and 0.5 equivalents of a hexabromidodicuprate(II) dianion. Both methoxy groups of the cationic pyridinium moiety are directed towards the N atom of the pyridine ring as a result of intramolecular N—H⋯O hydrogen bonds. The centrosymmetric hexabromidodicuprate dianion possesses a distorted tetrahedral geometry at the copper ion. The Cu—Br bond lengths are 2.3385 (7) and 2.3304 (7) Å for the terminal bromides, whereas the bond length between the Cu atom and two bridging bromides is slightly longer [2.4451 (6) Å].
Related literature
The neutral compound 2,6-bis(2-methoxyphenyl)pyridine has been previously reported (Silva et al., 1997) and copper(II) complexes of the related ligand 2,6-bis(2′-hydroxyphenyl)pyridine have also been characterized (Steinhauser et al., 2004).
Experimental
Crystal data
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Refinement
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Data collection: KappaCCD Server Software (Nonius, 1997); cell DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN; program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 and maXus (Mackay et al., 1999).
Supporting information
10.1107/S1600536811003588/vn2002sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536811003588/vn2002Isup2.hkl
The title compound, (C9H18NO2).0.5(Cu2Br6) (1), was prepared from a reaction of CuBr2 (0.5 mmol) with one equivalent of 2,6-bis(2-methoxyphenyl)pyridine (0.5 mmol) in dichloromethane (30 ml) at room temperature for 3 h. The reaction solution was filtered to remove any unreacted CuBr2. X-ray quality single crystals were obtained from slow evaporation of a dichloromethane solution of 1 at room temperature.
Structure
was performed using least-squares analysis. All non-H atoms were refined anisotropically whereas all H atoms were placed in calculated positions and treated as riding with C,N—H = 0.96 with Uiso(H) = 1.2 Ueq(C,N), including the methoxy H atoms.Data collection: KappaCCD Server Software (Nonius, 1997); cell
DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and maXus (Mackay et al., 1999).Fig. 1. ORTEP diagram of the title compound (1). Displacement ellipsoids are drawn at the 30% probability level. |
(C19H18NO2)2[Cu2Br6] | F(000) = 2312 |
Mr = 1191.23 | Dx = 1.920 Mg m−3 |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2ab | Cell parameters from 32254 reflections |
a = 11.5329 (1) Å | θ = 1.0–26.4° |
b = 17.0104 (4) Å | µ = 6.89 mm−1 |
c = 21.0021 (5) Å | T = 298 K |
V = 4120.18 (14) Å3 | Cube, dark green |
Z = 4 | 0.25 × 0.20 × 0.18 mm |
Nonius KappaCCD diffractometer | 3240 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.075 |
ω scans | θmax = 26.4°, θmin = 2.9° |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | h = −14→14 |
Tmin = 0.207, Tmax = 0.301 | k = −21→21 |
28095 measured reflections | l = −22→26 |
4177 independent reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.042 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.104 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0575P)2 + 1.1145P] where P = (Fo2 + 2Fc2)/3 |
4177 reflections | (Δ/σ)max < 0.001 |
235 parameters | Δρmax = 0.36 e Å−3 |
0 restraints | Δρmin = −0.55 e Å−3 |
(C19H18NO2)2[Cu2Br6] | V = 4120.18 (14) Å3 |
Mr = 1191.23 | Z = 4 |
Orthorhombic, Pbca | Mo Kα radiation |
a = 11.5329 (1) Å | µ = 6.89 mm−1 |
b = 17.0104 (4) Å | T = 298 K |
c = 21.0021 (5) Å | 0.25 × 0.20 × 0.18 mm |
Nonius KappaCCD diffractometer | 4177 independent reflections |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | 3240 reflections with I > 2σ(I) |
Tmin = 0.207, Tmax = 0.301 | Rint = 0.075 |
28095 measured reflections |
R[F2 > 2σ(F2)] = 0.042 | 0 restraints |
wR(F2) = 0.104 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.36 e Å−3 |
4177 reflections | Δρmin = −0.55 e Å−3 |
235 parameters |
Experimental. multi-scan from symmetry-related measurements SORTAV (Blessing 1995) |
Geometry. All standard uncertainties (except dihedral angles between l.s. planes) are estimated using the full covariance matrix. The standard uncertainties in cell dimensions are are used in calculating the standard uncertainties of bond distances, angles and torsion angles. Angles between l.s. planes have standard uncertainties calculated from atomic positional standard uncertainties; the errors in cell dimensions are not used in this case. |
x | y | z | Uiso*/Ueq | ||
Br1 | −0.03538 (4) | 0.45904 (3) | 0.07154 (2) | 0.07414 (19) | |
Br2 | 0.14159 (4) | 0.30603 (3) | 0.00330 (2) | 0.05795 (15) | |
Br3 | 0.31781 (4) | 0.47771 (3) | −0.02118 (2) | 0.06266 (16) | |
Cu1 | 0.12512 (4) | 0.44281 (3) | −0.00337 (2) | 0.05014 (16) | |
N1 | 0.3781 (2) | 0.23294 (16) | 0.25843 (14) | 0.0384 (7) | |
H20 | 0.3754 | 0.2367 | 0.2128 | 0.046* | |
O1 | 0.3184 (2) | 0.16507 (18) | 0.15107 (14) | 0.0609 (8) | |
O2 | 0.4577 (2) | 0.30722 (17) | 0.15766 (13) | 0.0571 (7) | |
C1 | 0.2958 (3) | 0.1857 (2) | 0.28504 (18) | 0.0438 (9) | |
C2 | 0.2983 (4) | 0.1787 (3) | 0.3505 (2) | 0.0613 (11) | |
H2 | 0.2431 | 0.1451 | 0.3713 | 0.074* | |
C3 | 0.3783 (4) | 0.2192 (3) | 0.3857 (2) | 0.0678 (12) | |
H3 | 0.3768 | 0.2142 | 0.4312 | 0.081* | |
C4 | 0.4595 (3) | 0.2663 (2) | 0.35705 (19) | 0.0535 (10) | |
H4 | 0.5156 | 0.2941 | 0.3822 | 0.064* | |
C5 | 0.4602 (3) | 0.2733 (2) | 0.29171 (17) | 0.0388 (8) | |
C6 | 0.2118 (3) | 0.1434 (2) | 0.2446 (2) | 0.0461 (9) | |
C7 | 0.2227 (3) | 0.1327 (2) | 0.1792 (2) | 0.0500 (10) | |
C8 | 0.1406 (4) | 0.0902 (3) | 0.1446 (3) | 0.0658 (12) | |
H8 | 0.1496 | 0.0835 | 0.0995 | 0.079* | |
C9 | 0.0476 (4) | 0.0583 (3) | 0.1753 (3) | 0.0768 (16) | |
H9 | −0.0088 | 0.0294 | 0.1512 | 0.092* | |
C10 | 0.0341 (4) | 0.0672 (3) | 0.2395 (3) | 0.0751 (15) | |
H10 | −0.0311 | 0.0436 | 0.2606 | 0.090* | |
C11 | 0.1135 (3) | 0.1099 (3) | 0.2742 (2) | 0.0614 (12) | |
H11 | 0.1027 | 0.1172 | 0.3191 | 0.074* | |
C12 | 0.3434 (4) | 0.1461 (3) | 0.0865 (2) | 0.0712 (13) | |
H12A | 0.4127 | 0.1730 | 0.0734 | 0.085* | |
H12B | 0.2798 | 0.1624 | 0.0600 | 0.085* | |
H12C | 0.3544 | 0.0904 | 0.0824 | 0.085* | |
C13 | 0.5483 (3) | 0.3218 (2) | 0.25782 (18) | 0.0421 (8) | |
C14 | 0.5472 (3) | 0.3374 (2) | 0.19176 (19) | 0.0445 (9) | |
C15 | 0.6341 (4) | 0.3824 (2) | 0.1641 (2) | 0.0569 (11) | |
H15 | 0.6337 | 0.3919 | 0.1191 | 0.068* | |
C16 | 0.7214 (4) | 0.4135 (3) | 0.2013 (3) | 0.0671 (13) | |
H16 | 0.7812 | 0.4448 | 0.1821 | 0.081* | |
C17 | 0.7238 (3) | 0.4001 (3) | 0.2657 (3) | 0.0669 (13) | |
H17 | 0.7844 | 0.4222 | 0.2914 | 0.080* | |
C18 | 0.6385 (3) | 0.3547 (2) | 0.2938 (2) | 0.0550 (10) | |
H18 | 0.6421 | 0.3458 | 0.3389 | 0.066* | |
C19 | 0.4346 (4) | 0.3398 (3) | 0.0959 (2) | 0.0667 (12) | |
H19A | 0.3696 | 0.3133 | 0.0772 | 0.080* | |
H19B | 0.5016 | 0.3331 | 0.0693 | 0.080* | |
H19C | 0.4174 | 0.3948 | 0.1000 | 0.080* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0777 (3) | 0.0785 (4) | 0.0662 (3) | 0.0310 (2) | 0.0336 (2) | 0.0342 (3) |
Br2 | 0.0599 (3) | 0.0497 (3) | 0.0643 (3) | 0.00570 (18) | 0.01288 (19) | 0.0059 (2) |
Br3 | 0.0578 (3) | 0.0655 (3) | 0.0646 (3) | −0.00476 (19) | 0.0102 (2) | 0.0042 (2) |
Cu1 | 0.0534 (3) | 0.0490 (3) | 0.0480 (3) | 0.0075 (2) | 0.0124 (2) | 0.0064 (2) |
N1 | 0.0394 (16) | 0.0413 (16) | 0.0344 (16) | 0.0002 (12) | 0.0000 (12) | 0.0008 (13) |
O1 | 0.0662 (18) | 0.0702 (19) | 0.0464 (18) | −0.0161 (15) | 0.0017 (13) | −0.0131 (16) |
O2 | 0.0643 (17) | 0.0674 (19) | 0.0395 (16) | −0.0155 (14) | −0.0049 (12) | 0.0100 (14) |
C1 | 0.0392 (19) | 0.044 (2) | 0.048 (2) | 0.0010 (15) | 0.0072 (16) | 0.0039 (18) |
C2 | 0.062 (3) | 0.072 (3) | 0.050 (3) | −0.013 (2) | 0.011 (2) | 0.007 (2) |
C3 | 0.079 (3) | 0.086 (3) | 0.039 (2) | −0.009 (3) | 0.003 (2) | 0.004 (2) |
C4 | 0.060 (2) | 0.058 (3) | 0.043 (2) | −0.0058 (19) | −0.0026 (18) | −0.005 (2) |
C5 | 0.0388 (19) | 0.0363 (19) | 0.041 (2) | 0.0044 (14) | −0.0021 (14) | −0.0026 (16) |
C6 | 0.041 (2) | 0.036 (2) | 0.061 (3) | 0.0040 (14) | 0.0015 (17) | 0.0058 (18) |
C7 | 0.047 (2) | 0.042 (2) | 0.061 (3) | 0.0006 (16) | −0.0013 (18) | −0.0037 (19) |
C8 | 0.061 (3) | 0.055 (3) | 0.082 (4) | −0.004 (2) | −0.014 (2) | −0.014 (3) |
C9 | 0.054 (3) | 0.052 (3) | 0.124 (5) | −0.006 (2) | −0.020 (3) | −0.012 (3) |
C10 | 0.046 (3) | 0.054 (3) | 0.126 (5) | −0.0071 (19) | 0.003 (3) | 0.011 (3) |
C11 | 0.045 (2) | 0.054 (3) | 0.085 (3) | 0.0010 (19) | 0.009 (2) | 0.009 (2) |
C12 | 0.089 (3) | 0.071 (3) | 0.054 (3) | 0.001 (2) | 0.002 (2) | −0.020 (2) |
C13 | 0.0374 (18) | 0.039 (2) | 0.050 (2) | 0.0028 (14) | −0.0009 (15) | −0.0031 (17) |
C14 | 0.046 (2) | 0.040 (2) | 0.048 (2) | 0.0004 (16) | 0.0024 (16) | 0.0020 (17) |
C15 | 0.060 (3) | 0.052 (3) | 0.059 (3) | −0.001 (2) | 0.014 (2) | 0.010 (2) |
C16 | 0.050 (3) | 0.052 (3) | 0.099 (4) | −0.008 (2) | 0.012 (2) | 0.008 (3) |
C17 | 0.043 (2) | 0.062 (3) | 0.096 (4) | −0.006 (2) | −0.005 (2) | −0.007 (3) |
C18 | 0.049 (2) | 0.054 (2) | 0.062 (3) | −0.0034 (18) | −0.0075 (19) | −0.003 (2) |
C19 | 0.081 (3) | 0.077 (3) | 0.042 (3) | −0.005 (2) | −0.006 (2) | 0.011 (2) |
Br2—Cu1 | 2.3385 (7) | C2—H2 | 0.9600 |
Br3—Cu1 | 2.3304 (7) | C19—H19A | 0.9600 |
Br1—Cu1 | 2.4451 (6) | C19—H19B | 0.9600 |
C5—N1 | 1.362 (4) | C19—H19C | 0.9600 |
C5—C4 | 1.377 (5) | C3—H3 | 0.9600 |
C5—C13 | 1.490 (5) | C7—C6 | 1.392 (6) |
O2—C14 | 1.356 (4) | C7—C8 | 1.396 (6) |
O2—C19 | 1.435 (5) | C11—C6 | 1.413 (5) |
O1—C7 | 1.367 (5) | C11—H11 | 0.9600 |
O1—C12 | 1.423 (5) | C12—H12A | 0.9600 |
C14—C15 | 1.389 (5) | C12—H12B | 0.9600 |
C14—C13 | 1.413 (5) | C12—H12C | 0.9600 |
N1—C1 | 1.363 (4) | C13—C18 | 1.402 (5) |
N1—H20 | 0.9600 | C8—C9 | 1.364 (7) |
C10—C9 | 1.365 (8) | C8—H8 | 0.9600 |
C10—C11 | 1.377 (7) | C18—C17 | 1.382 (6) |
C10—H10 | 0.9601 | C18—H18 | 0.9600 |
C4—C3 | 1.372 (6) | C16—C17 | 1.372 (7) |
C4—H4 | 0.9600 | C16—H16 | 0.9600 |
C15—C16 | 1.380 (6) | C17—H17 | 0.9600 |
C15—H15 | 0.9598 | C9—H9 | 0.9600 |
C2—C3 | 1.368 (6) | C1—C6 | 1.476 (5) |
C2—C1 | 1.380 (6) | ||
Br3—Cu1—Br2 | 100.69 (2) | O1—C7—C8 | 122.1 (4) |
Br3—Cu1—Br1 | 142.79 (3) | C6—C7—C8 | 121.3 (4) |
Br2—Cu1—Br1 | 97.77 (2) | C10—C11—C6 | 121.0 (5) |
N1—C5—C4 | 117.6 (3) | C10—C11—H11 | 120.1 |
N1—C5—C13 | 120.5 (3) | C6—C11—H11 | 118.9 |
C4—C5—C13 | 121.8 (3) | O1—C12—H12A | 109.4 |
C14—O2—C19 | 118.1 (3) | O1—C12—H12B | 109.4 |
C7—O1—C12 | 118.9 (3) | H12A—C12—H12B | 109.5 |
O2—C14—C15 | 122.5 (4) | O1—C12—H12C | 109.6 |
O2—C14—C13 | 117.0 (3) | H12A—C12—H12C | 109.5 |
C15—C14—C13 | 120.5 (4) | H12B—C12—H12C | 109.5 |
C5—N1—C1 | 124.8 (3) | C18—C13—C14 | 117.4 (4) |
C5—N1—H20 | 120.1 | C18—C13—C5 | 118.0 (3) |
C1—N1—H20 | 115.2 | C14—C13—C5 | 124.5 (3) |
C9—C10—C11 | 120.3 (5) | C9—C8—C7 | 119.6 (5) |
C9—C10—H10 | 119.9 | C9—C8—H8 | 120.4 |
C11—C10—H10 | 119.8 | C7—C8—H8 | 120.1 |
C3—C4—C5 | 119.4 (4) | C17—C18—C13 | 121.4 (4) |
C3—C4—H4 | 120.5 | C17—C18—H18 | 118.5 |
C5—C4—H4 | 120.1 | C13—C18—H18 | 120.0 |
C16—C15—C14 | 120.1 (4) | C17—C16—C15 | 120.6 (4) |
C16—C15—H15 | 119.8 | C17—C16—H16 | 119.5 |
C14—C15—H15 | 120.1 | C15—C16—H16 | 119.9 |
C3—C2—C1 | 120.6 (4) | C16—C17—C18 | 120.0 (4) |
C3—C2—H2 | 120.0 | C16—C17—H17 | 120.2 |
C1—C2—H2 | 119.4 | C18—C17—H17 | 119.9 |
O2—C19—H19A | 109.5 | C8—C9—C10 | 120.9 (5) |
O2—C19—H19B | 109.4 | C8—C9—H9 | 119.1 |
H19A—C19—H19B | 109.5 | C10—C9—H9 | 120.0 |
O2—C19—H19C | 109.5 | N1—C1—C2 | 116.4 (3) |
H19A—C19—H19C | 109.5 | N1—C1—C6 | 120.6 (3) |
H19B—C19—H19C | 109.5 | C2—C1—C6 | 123.0 (3) |
C2—C3—C4 | 121.2 (4) | C7—C6—C11 | 117.0 (4) |
C2—C3—H3 | 118.9 | C7—C6—C1 | 124.9 (3) |
C4—C3—H3 | 120.0 | C11—C6—C1 | 118.1 (4) |
O1—C7—C6 | 116.5 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H20···O1 | 0.96 | 1.90 | 2.625 (4) | 131 |
N1—H20···O2 | 0.96 | 1.92 | 2.630 (4) | 129 |
Experimental details
Crystal data | |
Chemical formula | (C19H18NO2)2[Cu2Br6] |
Mr | 1191.23 |
Crystal system, space group | Orthorhombic, Pbca |
Temperature (K) | 298 |
a, b, c (Å) | 11.5329 (1), 17.0104 (4), 21.0021 (5) |
V (Å3) | 4120.18 (14) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 6.89 |
Crystal size (mm) | 0.25 × 0.20 × 0.18 |
Data collection | |
Diffractometer | Nonius KappaCCD diffractometer |
Absorption correction | Multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.207, 0.301 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 28095, 4177, 3240 |
Rint | 0.075 |
(sin θ/λ)max (Å−1) | 0.625 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.042, 0.104, 1.05 |
No. of reflections | 4177 |
No. of parameters | 235 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.36, −0.55 |
Computer programs: KappaCCD Server Software (Nonius, 1997), DENZO-SMN (Otwinowski & Minor, 1997), SIR92 (Altomare et al., 1994), PLATON (Spek, 2009), SHELXL97 (Sheldrick, 2008) and maXus (Mackay et al., 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H20···O1 | 0.96 | 1.90 | 2.625 (4) | 131 |
N1—H20···O2 | 0.96 | 1.92 | 2.630 (4) | 129 |
Acknowledgements
The authors acknowledge financial support from the Young Scientist and Technologist Programme (YSTP), the Center of Excellence for Innovation in Chemistry (PERCH-CIC) and the Office of the Higher Education Commission and Mahidol University under the National Research Universities Initiative.
References
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An attempt to synthesize copper(II) complex of 2,6-bis(2-methoxyphenyl)- pyridine in CH2Cl2 unexpectedly yielded the ionic complex (C9H18NO2).0.5(Cu2Br6). The single crystals of the title compound crystallizes in the orthorhombic unit cell in space group Pbca. Each asymmetric unit cell contains one molecule of 2,6-bis(2-methoxy- phenyl)pyridinium cation and half a molecule of hexabromodicuprate(II). Crystallographic data of the title compound reveals intramolecular N—H···O hydrogen bonds forcing both methoxy groups to be in close proximity to the nitrogen atom of the pyridinium ring (N···O distances of 2.625 (4) and 2.630 (4) Å). The pyridinium and two methoxyphenyl rings are almost co-planar, having the dihedral angles between them of 7.5 (5)° and 15.0 (5)°. In addition, weak intermolecular π-π stacking interactions between pyridine and phenyl moieties of the neighboring molecules with centroid-centroid distances of 3.649 (2) and 3.850 (2) Å are present.
Note that the centroid of the complete dianion coincides with the inversion center. Moreover, the hexabromodicuprate(II) dianion displays a distorted tetrahedral geometry at both copper(II) ions with Cu—Br bond distances of 2.3385 (7) and 2.3304 (7) Å for terminal bromides, and 2.4451 (6) Å for bridging bromides, respectively.
The neutral compound 2,6-bis(2-methoxyphenyl)pyridine has been previously reported (Silva et al., 1997) and their crystals were obtained from an ethyl acetate solution. The published crystal structure reveals that both methoxy groups are on opposite sides of the pyridine nitrogen to avoid the N···O lone pair repulsion. In addition, copper(II) complexes of the related ligand 2,6-bis(2'- hydroxyphenyl)pyridine have previously been synthesized and characterized (Steinhauser et al., 2004).