p-Dicyanobenzene and p-diisocyanobenzene are not isomorphous. The title compound, C8H4N2, is isomorphous with p-dicyanobenzene. The molecule lies on a center of symmetry and is end-for-end disordered. The bond lengths and angles lie within normal ranges, but the precise values are obscured by the disorder.
Supporting information
CCDC reference: 189380
Key indicators
- Single-crystal X-ray study
- T = 173 K
- Mean (C-C) = 0.002 Å
- R factor = 0.049
- wR factor = 0.133
- Data-to-parameter ratio = 13.8
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
Data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); 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.
p-isocyanobenzonitrile
top
Crystal data top
C8H4N2 | Z = 1 |
Mr = 128.13 | F(000) = 66 |
Triclinic, P1 | Dx = 1.279 Mg m−3 |
a = 3.7923 (11) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 6.4680 (18) Å | Cell parameters from 1186 reflections |
c = 7.504 (2) Å | θ = 3.0–27.5° |
α = 113.099 (10)° | µ = 0.08 mm−1 |
β = 94.412 (10)° | T = 173 K |
γ = 97.128 (10)° | Needle, colorless |
V = 166.41 (8) Å3 | 0.50 × 0.15 × 0.10 mm |
Data collection top
Siemens SMART area-detector diffractometer | 747 independent reflections |
Radiation source: fine-focus sealed tube | 610 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.026 |
ω scans | θmax = 27.5°, θmin = 3.0° |
Absorption correction: multi-scan SADABS (Sheldrick, 1996; Blessing, 1995) | h = −4→4 |
Tmin = 0.97, Tmax = 0.99 | k = −8→8 |
1941 measured reflections | l = −9→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)] = 0.049 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.133 | All H-atom parameters refined |
S = 1.07 | w = 1/[σ2(Fo2) + (0.079P)2 + 0.0192P] where P = (Fo2 + 2Fc2)/3 |
747 reflections | (Δ/σ)max = 0.001 |
54 parameters | Δρmax = 0.22 e Å−3 |
0 restraints | Δρmin = −0.21 e Å−3 |
Special details top
Refinement. Atoms C7(N7) and C8(N8) were assumed to have 50/50 disorder between C and N. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
C1 | 0.1172 (3) | 0.5945 (2) | 0.69825 (18) | 0.0310 (4) | |
C2 | 0.1421 (3) | 0.3664 (2) | 0.5875 (2) | 0.0329 (4) | |
H2 | 0.242 (4) | 0.281 (2) | 0.653 (2) | 0.037 (4)* | |
C3 | 0.0251 (3) | 0.2717 (2) | 0.3886 (2) | 0.0333 (4) | |
H3 | 0.042 (4) | 0.113 (3) | 0.305 (2) | 0.043 (4)* | |
C7 | 0.2402 (3) | 0.6929 (2) | 0.90203 (18) | 0.0365 (4) | 0.50 |
N7 | 0.2402 (3) | 0.6929 (2) | 0.90203 (18) | 0.0365 (4) | 0.50 |
C8 | 0.3426 (4) | 0.7754 (2) | 1.0717 (2) | 0.0447 (4) | 0.50 |
N8 | 0.3426 (4) | 0.7754 (2) | 1.0717 (2) | 0.0447 (4) | 0.50 |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0234 (6) | 0.0372 (7) | 0.0331 (7) | 0.0056 (5) | 0.0056 (5) | 0.0146 (6) |
C2 | 0.0282 (7) | 0.0368 (7) | 0.0384 (8) | 0.0089 (5) | 0.0059 (5) | 0.0191 (6) |
C3 | 0.0299 (7) | 0.0330 (7) | 0.0371 (8) | 0.0083 (5) | 0.0073 (5) | 0.0131 (6) |
C7 | 0.0323 (7) | 0.0371 (7) | 0.0424 (8) | 0.0085 (5) | 0.0063 (5) | 0.0177 (6) |
N7 | 0.0323 (7) | 0.0371 (7) | 0.0424 (8) | 0.0085 (5) | 0.0063 (5) | 0.0177 (6) |
C8 | 0.0476 (8) | 0.0441 (8) | 0.0427 (8) | 0.0114 (6) | 0.0042 (6) | 0.0173 (6) |
N8 | 0.0476 (8) | 0.0441 (8) | 0.0427 (8) | 0.0114 (6) | 0.0042 (6) | 0.0173 (6) |
Geometric parameters (Å, º) top
C1—C2 | 1.4004 (19) | C2—H2 | 0.961 (15) |
C1—C3i | 1.4030 (19) | C3—C1i | 1.4030 (19) |
C1—C7 | 1.4192 (17) | C3—H3 | 0.986 (16) |
C2—C3 | 1.3833 (19) | C7—C8 | 1.1814 (17) |
| | | |
C2—C1—C3i | 121.27 (12) | C1—C2—H2 | 118.4 (9) |
C2—C1—C7 | 119.41 (11) | C2—C3—C1i | 119.47 (12) |
C3i—C1—C7 | 119.32 (11) | C2—C3—H3 | 121.8 (9) |
C3—C2—C1 | 119.26 (12) | C1i—C3—H3 | 118.8 (9) |
C3—C2—H2 | 122.3 (9) | C8—C7—C1 | 179.82 (12) |
Symmetry code: (i) −x, −y+1, −z+1. |
Cell constants (Å, °) top | p-Dicyanobenzene | | p-Isocyanobenzonitrile | |
| 297 Ki | 173 Kii | 297 Kii | 173 Kiii |
a | 3.843 (1) | 3.795 (1) | 3.836 (1) | 3.792 (1) |
b | 6.575 (2) | 6.494 (2) | 6.483 (2) | 6.468 (2) |
c | 7.313 (2) | 7.302 (2) | 7.618 (2) | 7.504 (2) |
α | 114.50 (2) | 114.15 (1) | 112.96 (1) | 113.10 (1) |
β | 93.53 (3) | 92.87 (1) | 97.08 (1) | 94.41 (1) |
γ | 96.99 (3) | 97.77 (1) | 95.88 (1) | 97.13 (1) |
V | 165.6 (1) | 161.6 (1) | 170.7 (1) | 166.4 (1) |
References: (i) Colapietro, Domenicano, Portalone, Schultz & Hargittai (1984);
(ii) SMART CCD measurements, this lab; (iii) this work. |