Equimolar mixtures of
ortho- and
meta-, or
ortho- and
para-, or
meta- and
para-tetrachlorodicyanobenzene, C
6Cl
4(CN)
2, form structures with disordered layers containing both kinds of molecules in rhombohedral or pseudo-rhombohedral cells. These structures are similar to the structure of the rhombohedral form of the
meta isomer. The guiding force appears to be an intermolecular synthon, in which a nitrile group in one molecule interacts with Cl atoms in two adjacent molecules with N
Cl distances of approximately 3.1 Å.
Supporting information
CCDC references: 722681; 722682; 722683
For all compounds, data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
(M-II)
m-tetrachlorodicyanobenzene polymorph II
top
Crystal data top
C8Cl4N2 | F(000) = 390 |
Mr = 265.90 | Dx = 1.812 Mg m−3 |
Rhombohedral, R3m:H | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -R 3 2" | Cell parameters from 2211 reflections |
a = 9.2171 (14) Å | θ = 3.3–27.4° |
c = 9.935 (2) Å | µ = 1.17 mm−1 |
α = 90° | T = 173 K |
γ = 120° | Prism, colorless |
V = 731.0 (2) Å3 | 0.50 × 0.35 × 0.25 mm |
Z = 3 | |
Data collection top
Bruker 1X CCD area detector duiffractometer | 226 independent reflections |
Radiation source: fine-focus sealed tube | 216 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.031 |
ω scans | θmax = 27.5°, θmin = 3.3° |
Absorption correction: multi-scan SADABS; Sheldrick, 1996; Blessing, 1995 | h = −11→11 |
Tmin = 0.64, Tmax = 0.75 | k = −11→11 |
2730 measured reflections | l = −12→12 |
Refinement top
Refinement on F2 | 4 restraints |
Least-squares matrix: full | Primary atom site location: structure-invariant direct methods |
R[F2 > 2σ(F2)] = 0.031 | Secondary atom site location: difference Fourier map |
wR(F2) = 0.086 | w = 1/[σ2(Fo2) + (0.045P)2 + 0.495P]
where P = (Fo2 + 2Fc2)/3 |
S = 1.24 | (Δ/σ)max = 0.001 |
226 reflections | Δρmax = 0.21 e Å−3 |
21 parameters | Δρmin = −0.27 e Å−3 |
Crystal data top
C8Cl4N2 | V = 731.0 (2) Å3 |
Mr = 265.90 | Z = 3 |
Rhombohedral, R3m:H | Mo Kα radiation |
a = 9.2171 (14) Å | µ = 1.17 mm−1 |
c = 9.935 (2) Å | T = 173 K |
α = 90° | 0.50 × 0.35 × 0.25 mm |
γ = 120° | |
Data collection top
Bruker 1X CCD area detector duiffractometer | 226 independent reflections |
Absorption correction: multi-scan SADABS; Sheldrick, 1996; Blessing, 1995 | 216 reflections with I > 2σ(I) |
Tmin = 0.64, Tmax = 0.75 | Rint = 0.031 |
2730 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.031 | 21 parameters |
wR(F2) = 0.086 | 4 restraints |
S = 1.24 | Δρmax = 0.21 e Å−3 |
226 reflections | Δρmin = −0.27 e Å−3 |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
C1 | 0.17335 (10) | 0.08667 (5) | −0.00031 (18) | 0.0379 (5) | |
Cl1 | 0.38779 (10) | 0.19390 (5) | −0.00679 (15) | 0.0506 (4) | 0.66667 |
C2 | 0.35431 (12) | 0.17715 (6) | 0.0037 (16) | 0.0506 (4) | 0.33333 |
N1 | 0.49728 (10) | 0.24864 (5) | 0.0077 (7) | 0.0534 (14) | 0.33333 |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0381 (10) | 0.0451 (8) | 0.0282 (8) | 0.0191 (5) | 0.0003 (7) | 0.0002 (4) |
Cl1 | 0.0343 (5) | 0.0629 (5) | 0.0450 (6) | 0.0172 (3) | 0.0017 (5) | 0.0008 (2) |
C2 | 0.0343 (5) | 0.0629 (5) | 0.0450 (6) | 0.0172 (3) | 0.0017 (5) | 0.0008 (2) |
N1 | 0.044 (4) | 0.056 (3) | 0.056 (4) | 0.0218 (19) | 0.001 (3) | 0.0006 (14) |
Geometric parameters (Å, º) top
C1—C1i | 1.3837 (8) | C1—Cl1 | 1.7130 (3) |
C1—C1ii | 1.3837 (8) | Cl1—N1 | 0.8858 (10) |
C1—C2 | 1.4450 (2) | C2—N1 | 1.1420 (2) |
| | | |
C1i—C1—C1ii | 119.998 (3) | C1i—C1—Cl1 | 119.987 (7) |
C1i—C1—C2 | 119.979 (15) | C1ii—C1—Cl1 | 119.988 (8) |
C1ii—C1—C2 | 119.980 (15) | N1—C2—C1 | 179.5 (14) |
Symmetry codes: (i) y, −x+y, −z; (ii) x−y, x, −z. |
(O-P)
o-tetrachlordicyanobenzene/
p-tetrachlordicyanobenzene 1/1
top
Crystal data top
C8Cl4N2 | Dx = 1.796 Mg m−3 |
Mr = 265.90 | Mo Kα radiation, λ = 0.71073 Å |
Hexagonal, R3m:H | Cell parameters from 1173 reflections |
Hall symbol: - R 3 2" | θ = 3.3–25.0° |
a = 9.2473 (8) Å | µ = 1.16 mm−1 |
c = 9.9590 (13) Å | T = 173 K |
V = 737.52 (13) Å3 | Prism, colorless |
Z = 3 | 0.45 × 0.35 × 0.30 mm |
F(000) = 390 | |
Data collection top
Bruker 1K area CCD area detector diffractometer | 176 independent reflections |
Radiation source: fine-focus sealed tube | 167 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.038 |
ω scans | θmax = 25.0°, θmin = 3.3° |
Absorption correction: multi-scan SADABS; Sheldrick, 1996; Blessing, 1995 | h = −8→10 |
Tmin = 0.64, Tmax = 0.71 | k = −10→10 |
1227 measured reflections | l = −11→9 |
Refinement top
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 | w = 1/[σ2(Fo2) + (0.058P)2 + 0.025P]
where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.086 | (Δ/σ)max = 0.001 |
S = 1.28 | Δρmax = 0.22 e Å−3 |
176 reflections | Δρmin = −0.22 e Å−3 |
22 parameters | Extinction correction: SHELXTL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
4 restraints | Extinction coefficient: 0.036 (10) |
Crystal data top
C8Cl4N2 | Z = 3 |
Mr = 265.90 | Mo Kα radiation |
Hexagonal, R3m:H | µ = 1.16 mm−1 |
a = 9.2473 (8) Å | T = 173 K |
c = 9.9590 (13) Å | 0.45 × 0.35 × 0.30 mm |
V = 737.52 (13) Å3 | |
Data collection top
Bruker 1K area CCD area detector diffractometer | 176 independent reflections |
Absorption correction: multi-scan SADABS; Sheldrick, 1996; Blessing, 1995 | 167 reflections with I > 2σ(I) |
Tmin = 0.64, Tmax = 0.71 | Rint = 0.038 |
1227 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.029 | 22 parameters |
wR(F2) = 0.086 | 4 restraints |
S = 1.28 | Δρmax = 0.22 e Å−3 |
176 reflections | Δρmin = −0.22 e Å−3 |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
Cl1 | 0.38797 (10) | 0.19398 (5) | −0.00711 (11) | 0.0536 (6) | 0.66667 |
C1 | 0.17423 (10) | 0.08712 (5) | −0.00036 (19) | 0.0375 (7) | |
C2 | 0.35453 (12) | 0.17726 (6) | 0.0053 (11) | 0.0536 (6) | 0.33333 |
N1 | 0.49708 (11) | 0.24854 (5) | 0.0083 (6) | 0.0537 (14) | 0.33333 |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cl1 | 0.0355 (7) | 0.0698 (7) | 0.0439 (8) | 0.0178 (4) | 0.0019 (4) | 0.00093 (18) |
C1 | 0.0385 (10) | 0.0446 (10) | 0.0272 (10) | 0.0193 (5) | 0.0003 (7) | 0.0002 (3) |
C2 | 0.0355 (7) | 0.0698 (7) | 0.0439 (8) | 0.0178 (4) | 0.0019 (4) | 0.00093 (18) |
N1 | 0.044 (3) | 0.058 (2) | 0.054 (4) | 0.0218 (17) | −0.003 (3) | −0.0017 (13) |
Geometric parameters (Å, º) top
Cl1—C1 | 1.7130 (2) | C1—C2 | 1.4450 (2) |
C1—C1i | 1.3953 (8) | C2—N1 | 1.1420 (1) |
C1—C1ii | 1.3953 (8) | | |
| | | |
C1i—C1—C1ii | 119.997 (3) | C1i—C1—Cl1 | 119.988 (8) |
C1i—C1—C2 | 119.961 (16) | C1ii—C1—Cl1 | 119.987 (8) |
C1ii—C1—C2 | 119.960 (16) | N1—C2—C1 | 179.2 (10) |
Symmetry codes: (i) y, −x+y, −z; (ii) x−y, x, −z. |
(M-P-II)
m-tetrachlorodicyanobenzene/
p- tetrachlorodicyanobenzene 1/1 polymorpth II
top
Crystal data top
C8Cl4N2 | F(000) = 260 |
Mr = 265.90 | Dx = 1.812 Mg m−3 |
Monoclinic, C2/m | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2y | Cell parameters from 2359 reflections |
a = 7.9237 (9) Å | θ = 3.1–27.5° |
b = 9.4546 (11) Å | µ = 1.17 mm−1 |
c = 6.5157 (7) Å | T = 173 K |
β = 93.106 (2)° | Prism, colorless |
V = 487.41 (9) Å3 | 0.35 × 0.35 × 0.30 mm |
Z = 2 | |
Data collection top
BRUKER 1K CCD area detector diffractometer | 589 independent reflections |
Radiation source: fine-focus sealed tube | 562 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.016 |
ω scans | θmax = 27.5°, θmin = 3.1° |
Absorption correction: multi-scan SADABS; Sheldrick, 1996; Blessing, 1995 | h = −10→10 |
Tmin = 0.58, Tmax = 0.70 | k = −12→12 |
2825 measured reflections | l = −8→8 |
Refinement top
Refinement on F2 | 9 restraints |
Least-squares matrix: full | Primary atom site location: structure-invariant direct methods |
R[F2 > 2σ(F2)] = 0.031 | Secondary atom site location: difference Fourier map |
wR(F2) = 0.080 | w = 1/[σ2(Fo2) + (0.039P)2 + 0.594P]
where P = (Fo2 + 2Fc2)/3 |
S = 1.08 | (Δ/σ)max = 0.001 |
589 reflections | Δρmax = 0.40 e Å−3 |
53 parameters | Δρmin = −0.46 e Å−3 |
Crystal data top
C8Cl4N2 | V = 487.41 (9) Å3 |
Mr = 265.90 | Z = 2 |
Monoclinic, C2/m | Mo Kα radiation |
a = 7.9237 (9) Å | µ = 1.17 mm−1 |
b = 9.4546 (11) Å | T = 173 K |
c = 6.5157 (7) Å | 0.35 × 0.35 × 0.30 mm |
β = 93.106 (2)° | |
Data collection top
BRUKER 1K CCD area detector diffractometer | 589 independent reflections |
Absorption correction: multi-scan SADABS; Sheldrick, 1996; Blessing, 1995 | 562 reflections with I > 2σ(I) |
Tmin = 0.58, Tmax = 0.70 | Rint = 0.016 |
2825 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.031 | 53 parameters |
wR(F2) = 0.080 | 9 restraints |
S = 1.08 | Δρmax = 0.40 e Å−3 |
589 reflections | Δρmin = −0.46 e Å−3 |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
Cl2 | 0.59393 (11) | 0.21874 (6) | 0.28866 (9) | 0.0420 (2) | 0.7852 (19) |
Cl1 | 0.7036 (3) | 0.5000 | 0.1082 (3) | 0.0525 (6) | 0.430 (4) |
C1 | 0.58745 (19) | 0.5000 | 0.3224 (2) | 0.0328 (5) | |
C2 | 0.54348 (19) | 0.37247 (10) | 0.4102 (2) | 0.0326 (4) | |
N1 | 0.7474 (3) | 0.5000 | −0.0133 (3) | 0.0434 (10) | 0.570 (4) |
N2 | 0.6256 (6) | 0.1252 (3) | 0.2781 (11) | 0.0491 (19) | 0.2148 (19) |
C11 | 0.6774 (12) | 0.5000 | 0.1353 (9) | 0.0525 (6) | 0.570 (4) |
C12 | 0.589 (2) | 0.2337 (4) | 0.3385 (14) | 0.0420 (2) | 0.2148 (19) |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cl2 | 0.0470 (4) | 0.0327 (4) | 0.0459 (4) | 0.0042 (2) | −0.0004 (3) | −0.0099 (2) |
Cl1 | 0.0405 (11) | 0.0844 (11) | 0.0330 (9) | 0.000 | 0.0062 (5) | 0.000 |
C1 | 0.0300 (11) | 0.0408 (13) | 0.0274 (10) | 0.000 | −0.0006 (8) | 0.000 |
C2 | 0.0316 (8) | 0.0323 (8) | 0.0332 (8) | 0.0018 (6) | −0.0035 (6) | −0.0040 (6) |
N1 | 0.051 (2) | 0.044 (2) | 0.036 (2) | 0.000 | 0.0121 (18) | 0.000 |
N2 | 0.059 (5) | 0.041 (5) | 0.048 (4) | 0.000 (4) | 0.007 (3) | −0.002 (3) |
C11 | 0.0405 (11) | 0.0844 (11) | 0.0330 (9) | 0.000 | 0.0062 (5) | 0.000 |
C12 | 0.0470 (4) | 0.0327 (4) | 0.0459 (4) | 0.0042 (2) | −0.0004 (3) | −0.0099 (2) |
Geometric parameters (Å, º) top
Cl2—C2 | 1.7130 (2) | C2—C2ii | 1.389 (3) |
Cl1—C1 | 1.7130 (2) | C2—C12 | 1.4451 (2) |
C1—C2i | 1.3871 (15) | N1—C11 | 1.1420 (1) |
C1—C2 | 1.3871 (16) | N2—C12 | 1.1421 (2) |
C1—C11 | 1.4450 (2) | | |
| | | |
C2i—C1—C2 | 120.74 (11) | C1—C2—C12 | 125.7 (4) |
C2i—C1—C11 | 119.63 (6) | C2ii—C2—C12 | 114.6 (3) |
C2—C1—C11 | 119.63 (6) | C1—C2—Cl2 | 118.47 (10) |
C2i—C1—Cl1 | 119.61 (6) | C2ii—C2—Cl2 | 121.88 (6) |
C2—C1—Cl1 | 119.61 (6) | N1—C11—C1 | 179.5 (10) |
C1—C2—C2ii | 119.63 (6) | N2—C12—C2 | 178.6 (6) |
Symmetry codes: (i) x, −y+1, z; (ii) −x+1, y, −z+1. |
Experimental details
| (M-II) | (O-P) | (M-P-II) |
Crystal data |
Chemical formula | C8Cl4N2 | C8Cl4N2 | C8Cl4N2 |
Mr | 265.90 | 265.90 | 265.90 |
Crystal system, space group | Rhombohedral, R3m:H | Hexagonal, R3m:H | Monoclinic, C2/m |
Temperature (K) | 173 | 173 | 173 |
a, b, c (Å) | 9.2171 (14), 9.2171 (14), 9.935 (2) | 9.2473 (8), 9.2473 (8), 9.9590 (13) | 7.9237 (9), 9.4546 (11), 6.5157 (7) |
α, β, γ (°) | 90, 90, 120 | 90, 90, 120 | 90, 93.106 (2), 90 |
V (Å3) | 731.0 (2) | 737.52 (13) | 487.41 (9) |
Z | 3 | 3 | 2 |
Radiation type | Mo Kα | Mo Kα | Mo Kα |
µ (mm−1) | 1.17 | 1.16 | 1.17 |
Crystal size (mm) | 0.50 × 0.35 × 0.25 | 0.45 × 0.35 × 0.30 | 0.35 × 0.35 × 0.30 |
|
Data collection |
Diffractometer | Bruker 1X CCD area detector duiffractometer | Bruker 1K area CCD area detector diffractometer | BRUKER 1K CCD area detector diffractometer |
Absorption correction | Multi-scan SADABS; Sheldrick, 1996; Blessing, 1995 | Multi-scan SADABS; Sheldrick, 1996; Blessing, 1995 | Multi-scan SADABS; Sheldrick, 1996; Blessing, 1995 |
Tmin, Tmax | 0.64, 0.75 | 0.64, 0.71 | 0.58, 0.70 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2730, 226, 216 | 1227, 176, 167 | 2825, 589, 562 |
Rint | 0.031 | 0.038 | 0.016 |
(sin θ/λ)max (Å−1) | 0.650 | 0.594 | 0.650 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.031, 0.086, 1.24 | 0.029, 0.086, 1.28 | 0.031, 0.080, 1.08 |
No. of reflections | 226 | 176 | 589 |
No. of parameters | 21 | 22 | 53 |
No. of restraints | 4 | 4 | 9 |
Δρmax, Δρmin (e Å−3) | 0.21, −0.27 | 0.22, −0.22 | 0.40, −0.46 |