Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101015384/jz1473sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270101015384/jz1473Isup2.hkl |
CCDC reference: 179253
Compound (I) was prepared by the reaction of CuCl (155.25 mg, 1.60 mmol), freshly prepared using the method given in Gmelin (1958), and 2,5-dimethylpyrazine (81 mg, 0.75 mmol) in acetonitrile (6 ml) at room temperature in a glass container. After stirring for 2 d, the mixture was allowed to stand at room temperature until most of the solvent had evaporated. The resulting precipitate was filtered off. The product consisted of a phase mixture of equivalent amounts of blue crystals of (I) and red crystals of a new compound, CuCl-2,5-dimethylpyrazine, which could be separated by hand.
Aromatic H atoms were positioned with idealized geometry and refined isotropically using a riding model, with C—H = 0.96 Å and Uiso(H) = 1.2Ueq(C). Methyl H atoms were identified from difference syntheses and their positions idealized, and then refined as rigid groups allowed to rotate but not tip, with C—H = 0.93 Å and Uiso(H) = 1.5Ueq(C). Query constraints.
Data collection: DIF4 (Stoe & Cie, 1992); cell refinement: DIF4; data reduction: REDU4 (Stoe & Cie, 1992); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL (Bruker, 1998); software used to prepare material for publication: SHELXL97.
[CuCl2(C6H8N2)(C2H3N)] | F(000) = 572 |
Mr = 283.64 | Dx = 1.703 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 11.653 (2) Å | Cell parameters from 46 reflections |
b = 7.3533 (12) Å | θ = 12.5–17.5° |
c = 13.443 (2) Å | µ = 2.42 mm−1 |
β = 106.190 (12)° | T = 293 K |
V = 1106.2 (3) Å3 | Block, blue |
Z = 4 | 0.11 × 0.09 × 0.08 mm |
Stoe AED-II diffractometer | 1678 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.027 |
Graphite monochromator | θmax = 27.0°, θmin = 2.7° |
ω/θ scans | h = 0→14 |
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1998) | k = −9→1 |
Tmin = 0.770, Tmax = 0.824 | l = −17→16 |
3045 measured reflections | 4 standard reflections every 120 min |
2415 independent reflections | intensity decay: none |
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)] = 0.029 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.073 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0369P)2] where P = (Fo2 + 2Fc2)/3 |
2415 reflections | (Δ/σ)max = 0.001 |
130 parameters | Δρmax = 0.34 e Å−3 |
0 restraints | Δρmin = −0.28 e Å−3 |
[CuCl2(C6H8N2)(C2H3N)] | V = 1106.2 (3) Å3 |
Mr = 283.64 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 11.653 (2) Å | µ = 2.42 mm−1 |
b = 7.3533 (12) Å | T = 293 K |
c = 13.443 (2) Å | 0.11 × 0.09 × 0.08 mm |
β = 106.190 (12)° |
Stoe AED-II diffractometer | 1678 reflections with I > 2σ(I) |
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1998) | Rint = 0.027 |
Tmin = 0.770, Tmax = 0.824 | 4 standard reflections every 120 min |
3045 measured reflections | intensity decay: none |
2415 independent reflections |
R[F2 > 2σ(F2)] = 0.029 | 0 restraints |
wR(F2) = 0.073 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.34 e Å−3 |
2415 reflections | Δρmin = −0.28 e Å−3 |
130 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Cu1 | 0.73261 (3) | 0.71726 (5) | 0.48792 (2) | 0.02628 (11) | |
Cl1 | 0.72904 (7) | 0.59965 (11) | 0.64217 (6) | 0.0410 (2) | |
Cl2 | 0.75918 (7) | 0.88033 (11) | 0.35349 (6) | 0.0423 (2) | |
N1 | 0.59361 (19) | 0.8873 (3) | 0.49430 (16) | 0.0260 (5) | |
C1 | 0.6161 (2) | 1.0527 (4) | 0.5397 (2) | 0.0264 (6) | |
C2 | 0.4796 (2) | 0.8372 (4) | 0.4560 (2) | 0.0279 (6) | |
H2 | 0.4633 | 0.7235 | 0.4250 | 0.033* | |
N2 | 0.89359 (19) | 0.5888 (3) | 0.49796 (17) | 0.0265 (5) | |
C3 | 0.7414 (2) | 1.1131 (4) | 0.5843 (2) | 0.0368 (7) | |
H3A | 0.7799 | 1.0357 | 0.6413 | 0.055* | |
H3B | 0.7421 | 1.2363 | 0.6082 | 0.055* | |
H3C | 0.7832 | 1.1065 | 0.5321 | 0.055* | |
C4 | 0.8976 (2) | 0.4497 (4) | 0.4342 (2) | 0.0300 (6) | |
H4 | 0.8267 | 0.4120 | 0.3873 | 0.036* | |
C5 | 0.9972 (2) | 0.6406 (4) | 0.5650 (2) | 0.0278 (6) | |
C6 | 0.9991 (3) | 0.7970 (5) | 0.6356 (3) | 0.0478 (8) | |
H6A | 0.9851 | 0.9077 | 0.5962 | 0.072* | |
H6B | 1.0756 | 0.8031 | 0.6862 | 0.072* | |
H6C | 0.9377 | 0.7813 | 0.6699 | 0.072* | |
N3 | 0.6138 (2) | 0.4894 (4) | 0.38692 (19) | 0.0400 (6) | |
C7 | 0.5697 (3) | 0.3725 (4) | 0.3344 (2) | 0.0336 (7) | |
C8 | 0.5158 (3) | 0.2221 (4) | 0.2678 (2) | 0.0425 (7) | |
H8A | 0.5638 | 0.1150 | 0.2880 | 0.064* | |
H8B | 0.5110 | 0.2517 | 0.1972 | 0.064* | |
H8C | 0.4370 | 0.2002 | 0.2743 | 0.064* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.02129 (17) | 0.02640 (17) | 0.03379 (18) | 0.00768 (16) | 0.01206 (12) | 0.00112 (16) |
Cl1 | 0.0475 (5) | 0.0413 (4) | 0.0403 (4) | 0.0119 (4) | 0.0220 (4) | 0.0075 (3) |
Cl2 | 0.0407 (4) | 0.0456 (5) | 0.0471 (4) | 0.0092 (4) | 0.0228 (4) | 0.0135 (4) |
N1 | 0.0235 (12) | 0.0248 (12) | 0.0319 (12) | 0.0064 (10) | 0.0116 (10) | 0.0026 (10) |
C1 | 0.0262 (14) | 0.0234 (14) | 0.0323 (14) | 0.0049 (12) | 0.0125 (12) | 0.0012 (11) |
C2 | 0.0258 (14) | 0.0226 (13) | 0.0371 (15) | 0.0043 (11) | 0.0120 (12) | −0.0016 (11) |
N2 | 0.0221 (12) | 0.0277 (12) | 0.0316 (11) | 0.0064 (10) | 0.0105 (10) | 0.0016 (10) |
C3 | 0.0277 (15) | 0.0314 (16) | 0.0515 (18) | 0.0042 (13) | 0.0113 (14) | −0.0062 (14) |
C4 | 0.0221 (14) | 0.0344 (16) | 0.0336 (14) | 0.0024 (12) | 0.0081 (12) | −0.0058 (13) |
C5 | 0.0217 (14) | 0.0281 (14) | 0.0341 (15) | 0.0010 (12) | 0.0085 (12) | −0.0021 (12) |
C6 | 0.0276 (16) | 0.050 (2) | 0.063 (2) | 0.0022 (16) | 0.0074 (15) | −0.0252 (18) |
N3 | 0.0321 (14) | 0.0418 (16) | 0.0468 (16) | −0.0017 (12) | 0.0124 (13) | −0.0026 (13) |
C7 | 0.0252 (15) | 0.0374 (17) | 0.0404 (16) | 0.0062 (14) | 0.0128 (13) | 0.0050 (15) |
C8 | 0.0381 (16) | 0.0420 (18) | 0.0475 (16) | 0.0002 (15) | 0.0117 (14) | −0.0037 (16) |
Cu1—N1 | 2.067 (2) | C3—H3B | 0.9600 |
Cu1—N2 | 2.071 (2) | C3—H3C | 0.9600 |
Cu1—Cl1 | 2.2577 (9) | C4—C5ii | 1.392 (4) |
Cu1—Cl2 | 2.2608 (8) | C4—H4 | 0.9300 |
Cu1—N3 | 2.349 (3) | C5—C4ii | 1.392 (4) |
N1—C2 | 1.336 (3) | C5—C6 | 1.487 (4) |
N1—C1 | 1.354 (3) | C6—H6A | 0.9600 |
C1—C2i | 1.392 (4) | C6—H6B | 0.9600 |
C1—C3 | 1.483 (4) | C6—H6C | 0.9600 |
C2—C1i | 1.392 (4) | N3—C7 | 1.140 (4) |
C2—H2 | 0.9300 | C7—C8 | 1.451 (4) |
N2—C4 | 1.343 (3) | C8—H8A | 0.9600 |
N2—C5 | 1.345 (3) | C8—H8B | 0.9600 |
C3—H3A | 0.9600 | C8—H8C | 0.9600 |
N1—Cu1—N2 | 168.36 (9) | H3A—C3—H3B | 109.5 |
N1—Cu1—Cl1 | 88.75 (6) | C1—C3—H3C | 109.5 |
N2—Cu1—Cl1 | 90.78 (6) | H3A—C3—H3C | 109.5 |
N1—Cu1—Cl2 | 89.77 (6) | H3B—C3—H3C | 109.5 |
N2—Cu1—Cl2 | 88.32 (6) | N2—C4—C5ii | 123.1 (3) |
Cl1—Cu1—Cl2 | 168.22 (3) | N2—C4—H4 | 118.5 |
N1—Cu1—N3 | 96.50 (9) | C5ii—C4—H4 | 118.5 |
N2—Cu1—N3 | 95.12 (9) | N2—C5—C4ii | 119.6 (2) |
Cl1—Cu1—N3 | 95.67 (7) | N2—C5—C6 | 119.8 (2) |
Cl2—Cu1—N3 | 96.11 (7) | C4ii—C5—C6 | 120.6 (2) |
C2—N1—C1 | 117.9 (2) | C5—C6—H6A | 109.5 |
C2—N1—Cu1 | 121.62 (18) | C5—C6—H6B | 109.5 |
C1—N1—Cu1 | 120.46 (18) | H6A—C6—H6B | 109.5 |
N1—C1—C2i | 119.0 (2) | C5—C6—H6C | 109.5 |
N1—C1—C3 | 119.8 (2) | H6A—C6—H6C | 109.5 |
C2i—C1—C3 | 121.3 (2) | H6B—C6—H6C | 109.5 |
N1—C2—C1i | 123.1 (3) | C7—N3—Cu1 | 170.8 (2) |
N1—C2—H2 | 118.5 | N3—C7—C8 | 178.9 (3) |
C1i—C2—H2 | 118.5 | C7—C8—H8A | 109.5 |
C4—N2—C5 | 117.3 (2) | C7—C8—H8B | 109.5 |
C4—N2—Cu1 | 119.84 (18) | H8A—C8—H8B | 109.5 |
C5—N2—Cu1 | 122.82 (18) | C7—C8—H8C | 109.5 |
C1—C3—H3A | 109.5 | H8A—C8—H8C | 109.5 |
C1—C3—H3B | 109.5 | H8B—C8—H8C | 109.5 |
Symmetry codes: (i) −x+1, −y+2, −z+1; (ii) −x+2, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C3—H3B···Cl1iii | 0.96 | 2.72 | 3.673 (3) | 171 |
C8—H8A···Cl2iv | 0.96 | 2.80 | 3.724 (3) | 163 |
Symmetry codes: (iii) x, y+1, z; (iv) x, y−1, z. |
Experimental details
Crystal data | |
Chemical formula | [CuCl2(C6H8N2)(C2H3N)] |
Mr | 283.64 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 293 |
a, b, c (Å) | 11.653 (2), 7.3533 (12), 13.443 (2) |
β (°) | 106.190 (12) |
V (Å3) | 1106.2 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.42 |
Crystal size (mm) | 0.11 × 0.09 × 0.08 |
Data collection | |
Diffractometer | Stoe AED-II diffractometer |
Absorption correction | Numerical (X-SHAPE; Stoe & Cie, 1998) |
Tmin, Tmax | 0.770, 0.824 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3045, 2415, 1678 |
Rint | 0.027 |
(sin θ/λ)max (Å−1) | 0.639 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.073, 1.00 |
No. of reflections | 2415 |
No. of parameters | 130 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.34, −0.28 |
Computer programs: DIF4 (Stoe & Cie, 1992), DIF4, REDU4 (Stoe & Cie, 1992), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), XP in SHELXTL (Bruker, 1998), SHELXL97.
Cu1—N1 | 2.067 (2) | Cu1—Cl2 | 2.2608 (8) |
Cu1—N2 | 2.071 (2) | Cu1—N3 | 2.349 (3) |
Cu1—Cl1 | 2.2577 (9) | ||
N1—Cu1—N2 | 168.36 (9) | N2—Cu1—N3 | 95.12 (9) |
N1—Cu1—Cl1 | 88.75 (6) | Cl1—Cu1—N3 | 95.67 (7) |
N2—Cu1—Cl1 | 90.78 (6) | Cl2—Cu1—N3 | 96.11 (7) |
N1—Cu1—Cl2 | 89.77 (6) | C2—N1—Cu1 | 121.62 (18) |
N2—Cu1—Cl2 | 88.32 (6) | C1—N1—Cu1 | 120.46 (18) |
Cl1—Cu1—Cl2 | 168.22 (3) | C4—N2—Cu1 | 119.84 (18) |
N1—Cu1—N3 | 96.50 (9) | C5—N2—Cu1 | 122.82 (18) |
D—H···A | D—H | H···A | D···A | D—H···A |
C3—H3B···Cl1i | 0.96 | 2.72 | 3.673 (3) | 170.5 |
C8—H8A···Cl2ii | 0.96 | 2.80 | 3.724 (3) | 162.6 |
Symmetry codes: (i) x, y+1, z; (ii) x, y−1, z. |
This study of the title compound, (I), is part of a project dealing with the synthesis and structural characterization of coordination polymers based on copper halides and multidentate amino ligands (Näther et al., 2001; Näther & Greve, 2001; Näther & Jess, 2001). 2,5-Dimethylpyrazine was selected because it is a suitable compound for the formation of coordination polymers via µ-N:N' coordination of two different metal cations. There are only a few compounds described in the literature which are based on this ligand, such as catena[(trifluoromethanesulfonato-O-)(µ2-2,5-dimethylpyrazine-N,N')- (2,5-dimethylpyrazine-N)copper(I)] (Otieno et al., 1990), and catena[tris(µ2-2,5-dimethylpyrazine)dicopper(I) bis(hexafluorophosphate)] and catena[bis(µ2-2,5-dimethylpyrazine)copper(I) hexafluorophosphate] (Otieno et al., 1993). In all of these compounds, one- or two-dimensional coordination polymers are formed in which the 2,5-dimethylpyrazine acts as a bridging ligand. \sch
In the crystal structure of (I), the Cu2+ cations are fivefold coordinated by two N atoms of two crystallographically independent 2,5-dimethylpyrazine ligands, one N atom of an acetonitrile ligand and two crystallographically independent Cl- anions (Fig. 1). The 2,5-dimethylpyrazine ligands are located around centres of inversion, whereas the Cu2+ cation, the Cl- anion and the acetonitrile molecule are located in general positions.
The coordination polyhedron around the Cu2+ cation can be described as a distorted tetragonal pyramid, with the Cl- anions and the N atoms of the 2,5-dimethylpyrazine ligands in the basal plane and the N atom of the acetonitrile ligand at the apex of the pyramid. The deviation of the Cu2+ cation from the plane formed by Cu1, Cl1, Cl2, N1 and N2 amounts to 0.1764 (7) Å. The Cu—Cl bond lengths are 2.2577 (9) and 2.2608 (8) Å, and the Cu—N distances to the 2,5-dimethylpyrazine ligand are 2.067 (2) and 2.071 (2) Å. The Cu—N distance of 2.349 (3) Å to the apical N atom is elongated compared with the other Cu—N distances, showing that this is a much weaker interaction. The N—Cu—N, Cl—Cu—Cl and N—Cu—Cl angles are in the ranges 168.36 (9)–168.22 (3)° or 88.32 (6)–90.78 (6)° (Table 1).
There are several structures known in the literature in which Cu2+ cations are five-coordinated by two Cl- ligands and three N atoms of organic ligands. A detailed analysis of their coordination polyhedra shows that most of them have a distorted tetragonal pyramidal coordination. In these cases, either the Cl- or the N ligand can occupy the apical position. However, the Cu—X distance to the apical ligand (X is Cl or N) is always much longer than those within the basal plane. The geometrical parameters in (I) are comparable with those found in some of the structures mentioned above if they contain one N atom in the apical position, e.g. dichloro-[6-ethoxy-6-hydroxy- 1,3,5-tri(2,6)pyridacyclohexaphane-2,4-dione]copper(II) ethanol solvate (Newkome et al., 1990) or dichloro-[1-(pent-3-ynyl)-1,4,7-triazacyclononane]copper(II) (Ellis et al., 1999). However, the exact geometry depends strongly on the nature of the organic ligands, e.g. whether mono- or multidentate ligands are present.
The 2,5-dimethylpyrazine ligands in (I) connect the Cu2+ cations into chains via µ-N:N' coordination (Fig. 2). The C—N—Cu angles deviate only slightly from 120° and the Cu2+ cation is located in the plane of the six-membered ring, which shows that the cation is oriented in the direction of the lone-pair on the N atom. For the longer Cu—N distance to the apical N atom, the lone-pair directionality is much less distinctive. The methyl groups of the 2,5-dimethylpyrazine ligands are located below the basal plane of the pyramid. Therefore, a possible coordination of the cations with the formation of an octahedral geometry, which is frequently observed for Cu2+ cations, is prevented.
There are some short intermolecular Cl···H distances between the Cl- anions and the methyl H atoms of neighbouring parallel chains, which may be interpreted as hydrogen bonds (Table 2).