A high-resolution X-ray diffraction measurement of 2,5-dichloro-1,4-benzoquinone (DCBQ) at 20 K was carried out. The experimental charge density was modeled using the Hansen–Coppens multipolar expansion and the topology of the electron density was analyzed in terms of the quantum theory of atoms in molecules (QTAIM). Two different multipole models, predominantly differentiated by the treatment of the chlorine atom, were obtained. The experimental results have been compared to theoretical results in the form of a multipolar refinement against theoretical structure factors and through direct topological analysis of the electron density obtained from the optimized periodic wavefunction. The similarity of the properties of the total electron density in all cases demonstrates the robustness of the Hansen–Coppens formalism. All intra- and intermolecular interactions have been characterized.
Supporting information
CCDC references: 1550937; 1550938
For both structures, data collection: CrystalClear, (2005); cell refinement: Otwinowski & Minor (1997); data reduction: Zhurova et al.,(1999), Zhurov et al.,(2008), Blessing, (1995,1997); program(s) used to solve structure: Sheldrick (2008); program(s) used to refine structure: Volkov et al., (2006); molecular graphics: Volkov et al., (2006), Stash, (2002,2005); software used to prepare material for publication: Volkov et al., (2006).
Crystal data top
C6H2Cl2O2 | F(000) = 176 |
Mr = 176.98 | Dx = 1.852 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 6.0246 (1) Å | Cell parameters from 50012 reflections |
b = 5.3112 (2) Å | θ = 3.4–70.9° |
c = 9.9258 (3) Å | µ = 0.94 mm−1 |
β = 92.585 (3)° | T = 20 K |
V = 317.28 (2) Å3 | Block, colourless |
Z = 2 | 0.25 × 0.21 × 0.15 mm |
Data collection top
Rigaku R-axis Rapid diffractometer | Rint = 0.012 |
w scans | θmax = 70.9° |
50012 measured reflections | h = −15→15 |
6041 independent reflections | k = 0→13 |
5464 reflections with I > 3σ, non−overlapped & non−partial reflections | l = 0→26 |
Refinement top
Refinement on F | H atoms treated by a mixture of independent and constrained refinement |
Least-squares matrix: full | w = 1/[σ2(Fo2) + (0.0024P)2 + 0.0063P] where P = (Fo2 + 2Fc2)/3 |
R[F2 > 2σ(F2)] = 0.008 | (Δ/σ)max < 0.001 |
wR(F2) = 0.007 | Δρmax = 0.19 e Å−3 |
S = 1.95 | Δρmin = −0.21 e Å−3 |
5464 reflections | Extinction correction: Becker-Coppens type 1 Lorentzian isotropic, Becker, P.J. & Coppens, P. (1974) Acta Cryst., A30, 129-153. |
241 parameters | Extinction coefficient: 0.0090 (8) |
0 restraints | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
CL(1) | 0.414997 (2) | 0.266682 (3) | 0.866303 (1) | 0.006 | |
O(1) | 0.152959 (12) | 0.706218 (16) | 0.777334 (8) | 0.008 | |
C(1) | 0.188671 (4) | 0.384324 (5) | 0.943392 (3) | 0.006 | |
C(2) | 0.082172 (4) | 0.611856 (5) | 0.879242 (3) | 0.006 | |
C(3) | 0.111499 (4) | 0.280415 (6) | 1.055484 (3) | 0.006 | |
H(1) | 0.190546 | 0.117385 | 1.101599 | 0.018 | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
CL(1) | 0.005614 (6) | 0.007663 (8) | 0.006016 (7) | 0.001166 (4) | 0.001601 (4) | −0.000222 (4) |
O(1) | 0.00870 (2) | 0.00872 (3) | 0.00639 (2) | 0.00016 (3) | 0.00266 (2) | 0.00212 (2) |
C(1) | 0.005537 (6) | 0.006108 (9) | 0.005376 (7) | 0.000654 (5) | 0.001396 (5) | 0.000377 (6) |
C(2) | 0.005726 (6) | 0.005909 (9) | 0.005103 (7) | 0.000195 (5) | 0.001375 (5) | 0.000600 (6) |
C(3) | 0.006587 (6) | 0.006715 (9) | 0.005765 (7) | 0.001253 (6) | 0.001721 (5) | 0.001172 (6) |
H(1) | 0.0229 (7) | 0.0173 (6) | 0.0151 (7) | 0.0087 (5) | 0.0041 (5) | 0.0050 (5) |
Geometric parameters (Å, º) top
CL(1)—C(1) | 1.7115 (1) | C(1)—C(3) | 1.3436 (1) |
O(1)—C(2) | 1.2228 (3) | C(2)—C(3)i | 1.4754 (1) |
C(1)—C(2) | 1.4969 (1) | C(3)—H(1) | 1.0800 (1) |
| | | |
CL(1)—C(1)—C(2) | 116.066 (6) | C(1)—C(2)—C(3)i | 117.296 (7) |
CL(1)—C(1)—C(3) | 122.186 (7) | C(1)—C(3)—C(2)i | 120.957 (8) |
C(2)—C(1)—C(3) | 121.746 (8) | C(1)—C(3)—H(1) | 121.187 (8) |
O(1)—C(2)—C(1) | 121.601 (14) | C(2)i—C(3)—H(1) | 117.849 (8) |
O(1)—C(2)—C(3)i | 121.102 (15) | | |
Symmetry code: (i) −x, −y+1, −z+2. |
Crystal data top
C6H2Cl2O2 | F(000) = 176 |
Mr = 176.98 | Dx = 1.852 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 6.0246 (1) Å | Cell parameters from 50012 reflections |
b = 5.3112 (2) Å | θ = 3.4–70.9° |
c = 9.9258 (3) Å | µ = 0.94 mm−1 |
β = 92.585 (3)° | T = 20 K |
V = 317.28 (2) Å3 | Block, colourless |
Z = 2 | 0.25 × 0.21 × 0.15 mm |
Data collection top
Rigaku R-axis Rapid diffractometer | Rint = 0.012 |
w scans | θmax = 70.9° |
50012 measured reflections | h = −15→15 |
6041 independent reflections | k = 0→13 |
5464 reflections with I > 3σ, non−overlapped & non−partial reflections | l = 0→26 |
Refinement top
Refinement on F | H atoms treated by a mixture of independent and constrained refinement |
Least-squares matrix: full | w = 1/[σ2(Fo2) + (0.0023P)2 + 0.0061P] where P = (Fo2 + 2Fc2)/3 |
R[F2 > 2σ(F2)] = 0.008 | (Δ/σ)max < 0.001 |
wR(F2) = 0.007 | Δρmax = 0.20 e Å−3 |
S = 1.89 | Δρmin = −0.21 e Å−3 |
5464 reflections | Extinction correction: Becker-Coppens type 1 Lorentzian isotropic, Becker, P.J. & Coppens, P. (1974) Acta Cryst., A30, 129-153. |
244 parameters | Extinction coefficient: 0.0138 (3) |
0 restraints | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
CL(1) | 0.415011 (1) | 0.266677 (1) | 0.866292 (1) | 0.006 | |
O(1) | 0.152974 (4) | 0.706209 (5) | 0.777328 (3) | 0.008 | |
C(1) | 0.188701 (1) | 0.384300 (2) | 0.943381 (1) | 0.006 | |
C(2) | 0.082178 (1) | 0.611856 (2) | 0.879239 (1) | 0.006 | |
C(3) | 0.111504 (1) | 0.280408 (2) | 1.055485 (1) | 0.006 | |
H(1) | 0.189028 | 0.116228 | 1.101329 | 0.019 | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
CL(1) | 0.005744 (3) | 0.007545 (3) | 0.005970 (3) | 0.001096 (2) | 0.001504 (2) | −0.000151 (2) |
O(1) | 0.008675 (8) | 0.008707 (10) | 0.006377 (8) | 0.000168 (9) | 0.002665 (7) | 0.002162 (7) |
C(1) | 0.005545 (2) | 0.006075 (3) | 0.005351 (2) | 0.000641 (2) | 0.001371 (2) | 0.000395 (2) |
C(2) | 0.005722 (2) | 0.005903 (3) | 0.005099 (2) | 0.000199 (2) | 0.001376 (2) | 0.000599 (2) |
C(3) | 0.006577 (2) | 0.006720 (3) | 0.005760 (2) | 0.001257 (2) | 0.001728 (2) | 0.001172 (2) |
H(1) | 0.0222 (2) | 0.0173 (2) | 0.0167 (2) | 0.00848 (15) | 0.00408 (16) | 0.00541 (15) |
Geometric parameters (Å, º) top
CL(1)—C(1) | 1.7114 (1) | C(1)—C(3) | 1.3437 (1) |
O(1)—C(2) | 1.2228 (3) | C(2)—C(3)i | 1.4755 (1) |
C(1)—C(2) | 1.4970 (1) | C(3)—H(1) | 1.0800 (1) |
| | | |
CL(1)—C(1)—C(2) | 116.069 (6) | C(1)—C(2)—C(3)i | 117.303 (7) |
CL(1)—C(1)—C(3) | 122.196 (7) | C(1)—C(3)—C(2)i | 120.964 (8) |
C(2)—C(1)—C(3) | 121.733 (7) | C(1)—C(3)—H(1) | 121.413 (8) |
O(1)—C(2)—C(1) | 121.591 (14) | C(2)i—C(3)—H(1) | 117.623 (8) |
O(1)—C(2)—C(3)i | 121.105 (15) | | |
Symmetry code: (i) −x, −y+1, −z+2. |