Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807030577/lh2430sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807030577/lh2430Isup2.hkl |
CCDC reference: 657662
Key indicators
- Single-crystal X-ray study
- T = 294 K
- Mean (C-C) = 0.004 Å
- R factor = 0.050
- wR factor = 0.137
- Data-to-parameter ratio = 16.2
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical . ?
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 1 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 0 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
The title compound was prepared by literature method (Xiong et al., 2006). Single crystals were obtained by slow evaporation of a heptane solution.
All H-atoms were discernible in a difference Fourier map. H atoms bound to C atoms were included in calculated positions and allowed to ride during refinement, with C—H = 0.93 Å, and Uiso(H) = 1.2Ueq(C).
In azobenzene compounds, a conversion from the trans to cis form can lead to photochromism. Photochromic compounds are of great interest for the control and measurement of radiation intensity, optical computers and display systems (Dürr & Bouas-Laurent, 1990) and for potential applications in molecular electronic devices (Martin et al., 1995). In addition, azo polymers have interest in various fields (Zhao et al., 1999). As a part of our investigation of preparing azo polymers, we report the crystal structure of the title compound.
There is an inversion center at the mid-point of the N═N bond. The central N═N bond length of 1.228 (4) Å is slightly shorter than the average value of 1.257 Å for azobenzene N═N bonds (Allen et al., 1987). But the C1—N1 bond length of 1.437 (3) Å is almost the same as the average value (1.43 Å). The molecular structure is shown in Fig. 1.
For background information, see: Dürr & Bouas-Laurent (1990); Martin et al. (1995); Zhao et al. (1999). For the synthetic procedure, see: Xiong et al. (2006). For bond length data, see: Allen et al. (1987).
Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXTL.
Fig. 1. The molecular structure with displacement ellipsoids drawn at the 50% probability level [symmetry code: (a) 2 - x, 1 - y, 1 - z] |
C14H8Cl2N2O2 | F(000) = 312 |
Mr = 307.12 | Dx = 1.521 Mg m−3 |
Monoclinic, P21/c | Melting point: 374 K |
Hall symbol: -P 2ybc | Mo Kα radiation, λ = 0.71073 Å |
a = 12.7512 (15) Å | Cell parameters from 1015 reflections |
b = 3.9116 (4) Å | θ = 2.5–25.8° |
c = 16.6550 (14) Å | µ = 0.49 mm−1 |
β = 126.189 (6)° | T = 294 K |
V = 670.44 (12) Å3 | Block, red |
Z = 2 | 0.20 × 0.20 × 0.10 mm |
Bruker APEX CCD area-detector diffractometer | 1475 independent reflections |
Radiation source: fine-focus sealed tube | 1109 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.030 |
φ and ω scans | θmax = 27.2°, θmin = 2.0° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2001) | h = −15→16 |
Tmin = 0.909, Tmax = 0.953 | k = −4→5 |
3784 measured reflections | l = −20→21 |
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)] = 0.050 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.137 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0695P)2 + 0.1223P] where P = (Fo2 + 2Fc2)/3 |
1475 reflections | (Δ/σ)max < 0.001 |
91 parameters | Δρmax = 0.34 e Å−3 |
0 restraints | Δρmin = −0.21 e Å−3 |
C14H8Cl2N2O2 | V = 670.44 (12) Å3 |
Mr = 307.12 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 12.7512 (15) Å | µ = 0.49 mm−1 |
b = 3.9116 (4) Å | T = 294 K |
c = 16.6550 (14) Å | 0.20 × 0.20 × 0.10 mm |
β = 126.189 (6)° |
Bruker APEX CCD area-detector diffractometer | 1475 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2001) | 1109 reflections with I > 2σ(I) |
Tmin = 0.909, Tmax = 0.953 | Rint = 0.030 |
3784 measured reflections |
R[F2 > 2σ(F2)] = 0.050 | 0 restraints |
wR(F2) = 0.137 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.34 e Å−3 |
1475 reflections | Δρmin = −0.21 e Å−3 |
91 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 | ||
Cl1 | 0.85788 (6) | 0.37064 (18) | 0.72874 (5) | 0.0627 (3) | |
O1 | 0.63441 (18) | 0.6568 (6) | 0.62472 (14) | 0.0739 (6) | |
N1 | 0.95418 (18) | 0.5708 (5) | 0.46251 (13) | 0.0484 (5) | |
C1 | 0.7350 (2) | 0.6528 (5) | 0.54165 (16) | 0.0405 (5) | |
C2 | 0.84462 (19) | 0.5682 (6) | 0.54617 (15) | 0.0405 (5) | |
H2 | 0.9155 | 0.4622 | 0.6023 | 0.049* | |
C3 | 0.8461 (2) | 0.6448 (5) | 0.46547 (16) | 0.0427 (5) | |
C4 | 0.6292 (2) | 0.8121 (6) | 0.45726 (18) | 0.0494 (6) | |
H4 | 0.5566 | 0.8705 | 0.4547 | 0.059* | |
C5 | 0.7410 (2) | 0.7994 (6) | 0.38163 (18) | 0.0530 (6) | |
H5 | 0.7428 | 0.8478 | 0.3278 | 0.064* | |
C6 | 0.6323 (2) | 0.8824 (6) | 0.37792 (18) | 0.0551 (6) | |
H6 | 0.5612 | 0.9863 | 0.3214 | 0.066* | |
C7 | 0.7233 (2) | 0.5837 (6) | 0.62321 (17) | 0.0488 (6) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.0672 (5) | 0.0749 (5) | 0.0573 (4) | 0.0146 (3) | 0.0431 (4) | 0.0124 (3) |
O1 | 0.0552 (11) | 0.1128 (18) | 0.0736 (13) | 0.0100 (11) | 0.0490 (11) | 0.0056 (11) |
N1 | 0.0470 (11) | 0.0591 (12) | 0.0472 (10) | 0.0016 (9) | 0.0324 (9) | 0.0006 (9) |
C1 | 0.0392 (11) | 0.0402 (12) | 0.0454 (11) | −0.0048 (9) | 0.0268 (10) | −0.0066 (9) |
C2 | 0.0361 (11) | 0.0427 (12) | 0.0404 (11) | −0.0020 (9) | 0.0214 (9) | −0.0034 (9) |
C3 | 0.0417 (12) | 0.0445 (12) | 0.0475 (12) | −0.0053 (9) | 0.0294 (10) | −0.0065 (9) |
C4 | 0.0395 (12) | 0.0500 (14) | 0.0567 (13) | 0.0010 (10) | 0.0274 (11) | −0.0061 (10) |
C5 | 0.0551 (14) | 0.0593 (16) | 0.0464 (13) | −0.0021 (11) | 0.0309 (12) | 0.0019 (11) |
C6 | 0.0459 (14) | 0.0575 (15) | 0.0497 (13) | 0.0044 (11) | 0.0215 (11) | 0.0025 (11) |
C7 | 0.0431 (13) | 0.0547 (14) | 0.0529 (13) | −0.0052 (10) | 0.0306 (11) | −0.0076 (11) |
Cl1—C7 | 1.780 (2) | C2—H2 | 0.9300 |
O1—C7 | 1.183 (3) | C3—C5 | 1.379 (3) |
N1—N1i | 1.228 (4) | C4—C6 | 1.373 (4) |
N1—C3 | 1.437 (3) | C4—H4 | 0.9300 |
C1—C2 | 1.395 (3) | C5—C6 | 1.389 (3) |
C1—C4 | 1.395 (3) | C5—H5 | 0.9300 |
C1—C7 | 1.477 (3) | C6—H6 | 0.9300 |
C2—C3 | 1.388 (3) | ||
N1i—N1—C3 | 114.3 (2) | C6—C4—H4 | 120.0 |
C2—C1—C4 | 120.2 (2) | C1—C4—H4 | 120.0 |
C2—C1—C7 | 123.3 (2) | C3—C5—C6 | 119.7 (2) |
C4—C1—C7 | 116.5 (2) | C3—C5—H5 | 120.1 |
C3—C2—C1 | 118.9 (2) | C6—C5—H5 | 120.1 |
C3—C2—H2 | 120.6 | C4—C6—C5 | 120.4 (2) |
C1—C2—H2 | 120.6 | C4—C6—H6 | 119.8 |
C5—C3—C2 | 120.9 (2) | C5—C6—H6 | 119.8 |
C5—C3—N1 | 115.61 (19) | O1—C7—C1 | 126.4 (2) |
C2—C3—N1 | 123.46 (19) | O1—C7—Cl1 | 118.00 (19) |
C6—C4—C1 | 119.9 (2) | C1—C7—Cl1 | 115.57 (16) |
C4—C1—C2—C3 | −0.1 (3) | C2—C3—C5—C6 | 0.5 (4) |
C7—C1—C2—C3 | −179.9 (2) | N1—C3—C5—C6 | −179.6 (2) |
C1—C2—C3—C5 | −0.6 (3) | C1—C4—C6—C5 | −0.7 (4) |
C1—C2—C3—N1 | 179.61 (19) | C3—C5—C6—C4 | 0.1 (4) |
N1i—N1—C3—C5 | −179.1 (3) | C2—C1—C7—O1 | 178.0 (2) |
N1i—N1—C3—C2 | 0.8 (4) | C4—C1—C7—O1 | −1.8 (4) |
C2—C1—C4—C6 | 0.7 (3) | C2—C1—C7—Cl1 | −1.7 (3) |
C7—C1—C4—C6 | −179.5 (2) | C4—C1—C7—Cl1 | 178.46 (16) |
Symmetry code: (i) −x+2, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C14H8Cl2N2O2 |
Mr | 307.12 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 294 |
a, b, c (Å) | 12.7512 (15), 3.9116 (4), 16.6550 (14) |
β (°) | 126.189 (6) |
V (Å3) | 670.44 (12) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.49 |
Crystal size (mm) | 0.20 × 0.20 × 0.10 |
Data collection | |
Diffractometer | Bruker APEX CCD area-detector |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2001) |
Tmin, Tmax | 0.909, 0.953 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3784, 1475, 1109 |
Rint | 0.030 |
(sin θ/λ)max (Å−1) | 0.644 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.050, 0.137, 1.06 |
No. of reflections | 1475 |
No. of parameters | 91 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.34, −0.21 |
Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SAINT, SHELXTL (Bruker, 2001), SHELXTL, PLATON (Spek, 2003).
In azobenzene compounds, a conversion from the trans to cis form can lead to photochromism. Photochromic compounds are of great interest for the control and measurement of radiation intensity, optical computers and display systems (Dürr & Bouas-Laurent, 1990) and for potential applications in molecular electronic devices (Martin et al., 1995). In addition, azo polymers have interest in various fields (Zhao et al., 1999). As a part of our investigation of preparing azo polymers, we report the crystal structure of the title compound.
There is an inversion center at the mid-point of the N═N bond. The central N═N bond length of 1.228 (4) Å is slightly shorter than the average value of 1.257 Å for azobenzene N═N bonds (Allen et al., 1987). But the C1—N1 bond length of 1.437 (3) Å is almost the same as the average value (1.43 Å). The molecular structure is shown in Fig. 1.