Diels-Alder adducts of maleic ­anhydride and dienes: new compounds by crystallization

We have determined the crystal structures of bi­cyclo­[2.2.1]­hept-2-ene-endo-cis-5,6-di­carboxyl­ic anhydride, C₉H₈O₃, (I), 1,2,3,4,7,7-hexa­chloro­bi­cyclo­[2.2.1]­hept-2-ene-endo-cis-5,6-di­carboxyl­ic anhydride diethyl ether solvate, C₉H₂Cl₆O₃·0.16­C₄H₁₀O, (II), bi­cyclo­[2.2.1]­hept-2-ene-endo-cis-5,6-di­carboxyl­ic acid, C₉H₁₀O₄, (III), 1,2,3,4,7,7-hexa­chloro­bi­cyclo­[2.2.1]­hept-2-ene-endo-cis-5,6-di­carboxyl­ic acid, C₉H₄Cl₆O₄, (IVa) and (IVb), and ethyl 1,2,3,4,7,7-hexa­chloro-6-carboxybi­cyclo­[2.2.1]­hept-2-ene-endo-cis-5-carboxyl­ate monohydrate, C₁₁H₈Cl₆O₄·H₂O, (V). Compounds (I) and (II) were prepared by a standard Diels-Alder reaction from maleic anhydride and cyclo­penta­diene or hexa­chloro­cyclo­penta­diene, respectively. The crystal-growing processes of these compounds led to surprising results: rapid recrystallization of (I) from diethyl ether and (II) from petroleum ether gave crystals of these compounds, however, crystallization by slow evaporation techniques using common solvents yielded new compounds in which the five-membered heterocycle has been cleaved.

Computing details

For all compounds, data collection: SMART (Siemens, 1995); cell refinement: SMART; data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 1991).

(I) bicyclo[2.2.1]hept-2-ene-endo-cis-5,6-dicarboxylic anhydride

Crystal data

C9H8O3	Dx = 1.441 Mg m^−3
Mr = 164.15	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 7065 reflections
a = 5.926 (2) Å	θ = 1–25°
b = 9.489 (3) Å	µ = 0.11 mm^−1
c = 13.452 (5) Å	T = 173 K
V = 756.4 (4) Å^3	Block, colourless
Z = 4	0.50 × 0.40 × 0.18 mm
F(000) = 344

Data collection

Siemens CCD three-circle diffractometer	1155 independent reflections
Radiation source: fine-focus sealed tube	1082 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.037
ω scans	θmax = 28.7°, θmin = 2.6°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −8→8
Tmin = 0.948, Tmax = 0.981	k = −12→12
20569 measured reflections	l = −18→18

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.110	H-atom parameters constrained
S = 1.14	w = 1/[σ^2(Fo^2) + (0.0826P)^2 + 0.0338P] where P = (Fo^2 + 2Fc^2)/3
1155 reflections	(Δ/σ)max < 0.001
109 parameters	Δρmax = 0.35 e Å^−3
0 restraints	Δρmin = −0.24 e Å^−3

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.4506 (3)	0.38619 (15)	0.38354 (11)	0.0212 (3)
H1	0.5270	0.2939	0.3711	0.025*
C2	0.5923 (3)	0.48059 (15)	0.45206 (11)	0.0208 (3)
H2	0.7326	0.4316	0.4748	0.025*
C3	0.6486 (3)	0.61180 (17)	0.38476 (12)	0.0253 (3)
H3	0.7792	0.6711	0.4063	0.030*
C4	0.4273 (4)	0.68864 (17)	0.36767 (13)	0.0296 (4)
H4	0.3874	0.7782	0.3939	0.036*
C5	0.2991 (3)	0.60833 (18)	0.30933 (13)	0.0288 (4)
H5	0.1512	0.6301	0.2869	0.035*
C6	0.4315 (3)	0.47574 (16)	0.28505 (12)	0.0249 (3)
H6	0.3831	0.4233	0.2242	0.030*
C7	0.6743 (3)	0.53521 (18)	0.28384 (12)	0.0265 (3)
H7A	0.7016	0.6007	0.2278	0.032*
H7B	0.7910	0.4606	0.2851	0.032*
C8	0.2314 (3)	0.36648 (16)	0.43786 (13)	0.0246 (3)
C9	0.4384 (3)	0.51363 (17)	0.53771 (12)	0.0240 (3)
O1	0.2306 (2)	0.44609 (13)	0.52451 (9)	0.0276 (3)
O2	0.0700 (2)	0.29646 (14)	0.41689 (11)	0.0351 (3)
O3	0.4683 (3)	0.58680 (15)	0.60864 (9)	0.0352 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0238 (7)	0.0111 (6)	0.0286 (7)	0.0008 (5)	0.0015 (6)	−0.0004 (5)
C2	0.0217 (7)	0.0156 (6)	0.0251 (7)	0.0004 (6)	0.0012 (6)	0.0006 (5)
C3	0.0279 (8)	0.0194 (7)	0.0288 (7)	−0.0065 (6)	0.0042 (6)	0.0000 (6)
C4	0.0385 (10)	0.0154 (7)	0.0351 (8)	0.0044 (7)	0.0124 (8)	0.0065 (6)
C5	0.0270 (8)	0.0252 (8)	0.0342 (8)	0.0058 (7)	0.0039 (7)	0.0109 (6)
C6	0.0269 (8)	0.0225 (7)	0.0253 (7)	0.0011 (7)	−0.0010 (6)	0.0003 (6)
C7	0.0272 (8)	0.0258 (8)	0.0266 (7)	0.0007 (7)	0.0068 (6)	0.0017 (6)
C8	0.0251 (8)	0.0142 (6)	0.0345 (8)	0.0009 (6)	0.0010 (6)	0.0050 (6)
C9	0.0278 (8)	0.0184 (7)	0.0258 (7)	0.0022 (6)	0.0023 (6)	0.0044 (5)
O1	0.0265 (6)	0.0230 (6)	0.0332 (6)	0.0026 (5)	0.0080 (5)	0.0030 (5)
O2	0.0273 (6)	0.0241 (6)	0.0540 (8)	−0.0065 (6)	−0.0022 (6)	0.0069 (6)
O3	0.0490 (9)	0.0299 (7)	0.0267 (6)	0.0018 (6)	0.0042 (5)	−0.0042 (5)

Geometric parameters (Å, º)

C1—C8	1.502 (2)	C4—H4	0.9500
C1—C2	1.535 (2)	C5—C6	1.518 (2)
C1—C6	1.578 (2)	C5—H5	0.9500
C1—H1	1.0000	C6—C7	1.545 (2)
C2—C9	1.503 (2)	C6—H6	1.0000
C2—C3	1.575 (2)	C7—H7A	0.9900
C2—H2	1.0000	C7—H7B	0.9900
C3—C4	1.518 (3)	C8—O2	1.198 (2)
C3—C7	1.547 (2)	C8—O1	1.389 (2)
C3—H3	1.0000	C9—O3	1.193 (2)
C4—C5	1.332 (3)	C9—O1	1.400 (2)
C8—C1—C2	104.69 (13)	C4—C5—H5	126.1
C8—C1—C6	114.41 (14)	C6—C5—H5	126.1
C2—C1—C6	103.24 (12)	C5—C6—C7	100.42 (13)
C8—C1—H1	111.3	C5—C6—C1	107.62 (13)
C2—C1—H1	111.3	C7—C6—C1	97.96 (13)
C6—C1—H1	111.3	C5—C6—H6	116.1
C9—C2—C1	104.48 (13)	C7—C6—H6	116.1
C9—C2—C3	113.84 (13)	C1—C6—H6	116.1
C1—C2—C3	103.41 (12)	C6—C7—C3	94.05 (13)
C9—C2—H2	111.5	C6—C7—H7A	112.9
C1—C2—H2	111.5	C3—C7—H7A	112.9
C3—C2—H2	111.5	C6—C7—H7B	112.9
C4—C3—C7	100.25 (14)	C3—C7—H7B	112.9
C4—C3—C2	106.51 (13)	H7A—C7—H7B	110.3
C7—C3—C2	98.85 (12)	O2—C8—O1	119.75 (16)
C4—C3—H3	116.2	O2—C8—C1	130.15 (16)
C7—C3—H3	116.2	O1—C8—C1	110.09 (14)
C2—C3—H3	116.2	O3—C9—O1	119.88 (16)
C5—C4—C3	107.89 (14)	O3—C9—C2	130.14 (16)
C5—C4—H4	126.1	O1—C9—C2	109.96 (13)
C3—C4—H4	126.1	C8—O1—C9	110.63 (13)
C4—C5—C6	107.82 (16)
C8—C1—C2—C9	−2.86 (15)	C5—C6—C7—C3	49.16 (15)
C6—C1—C2—C9	117.18 (13)	C1—C6—C7—C3	−60.50 (13)
C8—C1—C2—C3	−122.25 (13)	C4—C3—C7—C6	−49.33 (14)
C6—C1—C2—C3	−2.21 (15)	C2—C3—C7—C6	59.35 (14)
C9—C2—C3—C4	−44.70 (18)	C2—C1—C8—O2	−176.41 (17)
C1—C2—C3—C4	68.03 (15)	C6—C1—C8—O2	71.3 (2)
C9—C2—C3—C7	−148.22 (14)	C2—C1—C8—O1	3.91 (16)
C1—C2—C3—C7	−35.49 (15)	C6—C1—C8—O1	−108.37 (15)
C7—C3—C4—C5	33.14 (17)	C1—C2—C9—O3	−177.39 (17)
C2—C3—C4—C5	−69.37 (16)	C3—C2—C9—O3	−65.3 (2)
C3—C4—C5—C6	−0.39 (18)	C1—C2—C9—O1	1.01 (16)
C4—C5—C6—C7	−32.57 (17)	C3—C2—C9—O1	113.10 (14)
C4—C5—C6—C1	69.33 (18)	O2—C8—O1—C9	176.83 (14)
C8—C1—C6—C5	48.63 (18)	C1—C8—O1—C9	−3.45 (17)
C2—C1—C6—C5	−64.50 (17)	O3—C9—O1—C8	−179.94 (15)
C8—C1—C6—C7	152.28 (13)	C2—C9—O1—C8	1.47 (17)
C2—C1—C6—C7	39.15 (14)

(II) 1,2,3,4,7,7-hexachlorobicyclo[2.2.1]hept-2-ene-endo-cis-5,6-dicarboxylic anhydride diethyl ether solvate

Crystal data

C9H2Cl6O3·0.16C4H10O	Dx = 1.854 Mg m^−3
Mr = 383.16	Mo Kα radiation, λ = 0.71073 Å
Trigonal, R3	Cell parameters from 512 reflections
Hall symbol: -R 3	θ = 1–20°
a = 29.639 (4) Å	µ = 1.25 mm^−1
c = 8.119 (2) Å	T = 173 K
V = 6176.8 (19) Å^3	Block, colourless
Z = 18	0.30 × 0.20 × 0.15 mm
F(000) = 3402

Data collection

Siemens CCD three-circle diffractometer	2811 independent reflections
Radiation source: fine-focus sealed tube	2314 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.045
ω scans	θmax = 26.4°, θmin = 2.4°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −36→37
Tmin = 0.706, Tmax = 0.835	k = −37→37
31306 measured reflections	l = −10→10

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.078	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0319P)^2 + 19.3097P] where P = (Fo^2 + 2Fc^2)/3
2811 reflections	(Δ/σ)max = 0.001
173 parameters	Δρmax = 0.73 e Å^−3
2 restraints	Δρmin = −0.38 e Å^−3

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
C1	0.32288 (9)	0.40866 (9)	0.3739 (3)	0.0236 (5)
H1	0.3598	0.4163	0.3724	0.028*
C2	0.31361 (9)	0.44191 (9)	0.2488 (3)	0.0251 (5)
H2	0.3461	0.4657	0.1866	0.030*
C3	0.29484 (10)	0.47295 (9)	0.3578 (3)	0.0252 (5)
Cl3	0.29797 (3)	0.52706 (3)	0.26211 (10)	0.0464 (2)
C4	0.24234 (9)	0.43351 (9)	0.4300 (3)	0.0230 (5)
Cl4	0.18418 (3)	0.42570 (3)	0.36819 (8)	0.03901 (18)
C5	0.25017 (9)	0.40453 (9)	0.5379 (3)	0.0215 (5)
Cl5	0.20471 (2)	0.35140 (3)	0.64147 (8)	0.03192 (16)
C6	0.30830 (9)	0.42379 (9)	0.5416 (3)	0.0230 (5)
Cl6	0.33108 (3)	0.40670 (3)	0.71498 (8)	0.03710 (17)
C7	0.32971 (9)	0.48300 (10)	0.5122 (3)	0.0280 (5)
Cl71	0.39703 (3)	0.51862 (3)	0.46847 (10)	0.04236 (19)
Cl72	0.31643 (3)	0.51406 (3)	0.67495 (9)	0.03886 (18)
C8	0.28509 (9)	0.35302 (10)	0.3245 (3)	0.0242 (5)
O2	0.27761 (7)	0.31351 (7)	0.3867 (2)	0.0313 (4)
C9	0.27141 (10)	0.40316 (10)	0.1365 (3)	0.0260 (5)
O3	0.25089 (8)	0.40991 (8)	0.0220 (2)	0.0374 (5)
O1	0.25653 (7)	0.35263 (6)	0.1891 (2)	0.0270 (4)
C11	0.3617 (6)	0.6579 (6)	0.4546 (18)	0.092 (4)*	0.33
H11A	0.3643	0.6786	0.5488	0.138*	0.33
H11B	0.3435	0.6217	0.4846	0.138*	0.33
H11C	0.3960	0.6674	0.4163	0.138*	0.33
C12	0.3333	0.6667	0.3124 (14)	0.143 (4)*
H12A	0.3514	0.7031	0.2861	0.172*	0.33
H12B	0.2996	0.6580	0.3536	0.172*	0.33
O13	0.327 (4)	0.6365 (16)	0.1648 (11)	0.117 (8)*	0.17

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0163 (11)	0.0244 (12)	0.0297 (12)	0.0098 (10)	0.0005 (9)	−0.0036 (10)
C2	0.0226 (12)	0.0254 (12)	0.0252 (12)	0.0105 (10)	0.0069 (10)	0.0026 (10)
C3	0.0274 (13)	0.0212 (12)	0.0276 (12)	0.0126 (11)	0.0023 (10)	0.0013 (10)
Cl3	0.0623 (5)	0.0302 (4)	0.0521 (4)	0.0272 (4)	0.0087 (4)	0.0121 (3)
C4	0.0201 (12)	0.0278 (13)	0.0247 (12)	0.0148 (10)	−0.0013 (9)	−0.0045 (10)
Cl4	0.0288 (3)	0.0604 (5)	0.0383 (4)	0.0301 (3)	−0.0026 (3)	0.0027 (3)
C5	0.0174 (11)	0.0250 (12)	0.0198 (11)	0.0088 (10)	0.0006 (9)	−0.0037 (9)
Cl5	0.0289 (3)	0.0317 (3)	0.0282 (3)	0.0100 (3)	0.0069 (2)	0.0046 (3)
C6	0.0214 (12)	0.0258 (12)	0.0238 (12)	0.0132 (10)	−0.0045 (9)	−0.0043 (10)
Cl6	0.0406 (4)	0.0486 (4)	0.0313 (3)	0.0292 (3)	−0.0153 (3)	−0.0080 (3)
C7	0.0205 (12)	0.0257 (13)	0.0345 (13)	0.0091 (11)	0.0004 (10)	−0.0082 (11)
Cl71	0.0207 (3)	0.0332 (4)	0.0579 (5)	0.0020 (3)	0.0024 (3)	−0.0138 (3)
Cl72	0.0386 (4)	0.0346 (4)	0.0427 (4)	0.0177 (3)	−0.0013 (3)	−0.0169 (3)
C8	0.0220 (12)	0.0288 (13)	0.0241 (12)	0.0143 (10)	0.0011 (9)	−0.0056 (10)
O2	0.0387 (11)	0.0248 (9)	0.0342 (10)	0.0188 (8)	0.0008 (8)	−0.0013 (8)
C9	0.0278 (13)	0.0302 (13)	0.0221 (12)	0.0162 (11)	0.0069 (10)	0.0004 (10)
O3	0.0455 (12)	0.0462 (12)	0.0254 (9)	0.0265 (10)	−0.0022 (8)	0.0009 (8)
O1	0.0279 (9)	0.0270 (9)	0.0267 (9)	0.0141 (8)	−0.0042 (7)	−0.0048 (7)

Geometric parameters (Å, º)

C1—C8	1.513 (3)	C6—Cl6	1.742 (2)
C1—C2	1.532 (3)	C7—Cl72	1.764 (2)
C1—C6	1.561 (3)	C7—Cl71	1.765 (2)
C1—H1	1.0000	C8—O2	1.190 (3)
C2—C9	1.509 (3)	C8—O1	1.384 (3)
C2—C3	1.565 (3)	C9—O3	1.182 (3)
C2—H2	1.0000	C9—O1	1.400 (3)
C3—C4	1.521 (3)	C11—C12	1.525 (15)
C3—C7	1.556 (3)	C11—H11A	0.9601
C3—Cl3	1.742 (2)	C11—H11B	0.9599
C4—C5	1.326 (3)	C11—H11C	0.9599
C4—Cl4	1.697 (2)	C12—O13	1.451 (9)
C5—C6	1.520 (3)	C12—H12A	0.9601
C5—Cl5	1.697 (2)	C12—H12B	0.9600
C6—C7	1.558 (3)
C8—C1—C2	104.60 (19)	C3—C7—C6	92.89 (18)
C8—C1—C6	112.60 (19)	C3—C7—Cl72	113.80 (17)
C2—C1—C6	103.24 (18)	C6—C7—Cl72	113.67 (18)
C8—C1—H1	112.0	C3—C7—Cl71	113.36 (18)
C2—C1—H1	112.0	C6—C7—Cl71	113.99 (17)
C6—C1—H1	112.0	Cl72—C7—Cl71	108.61 (13)
C9—C2—C1	104.94 (19)	O2—C8—O1	121.1 (2)
C9—C2—C3	112.7 (2)	O2—C8—C1	129.2 (2)
C1—C2—C3	103.54 (19)	O1—C8—C1	109.7 (2)
C9—C2—H2	111.7	O3—C9—O1	120.5 (2)
C1—C2—H2	111.7	O3—C9—C2	130.3 (2)
C3—C2—H2	111.7	O1—C9—C2	109.1 (2)
C4—C3—C7	99.37 (18)	C8—O1—C9	111.65 (18)
C4—C3—C2	107.09 (19)	C12—C11—C11^i	55.5 (5)
C7—C3—C2	99.84 (19)	C12—C11—C11^ii	55.5 (5)
C4—C3—Cl3	116.27 (17)	C11^i—C11—C11^ii	60.002 (4)
C7—C3—Cl3	117.28 (17)	C12—C11—H11A	111.7
C2—C3—Cl3	114.71 (17)	C12—C11—H11B	109.4
C5—C4—C3	108.0 (2)	H11A—C11—H11B	109.5
C5—C4—Cl4	127.02 (19)	C12—C11—H11C	107.3
C3—C4—Cl4	124.75 (18)	H11A—C11—H11C	109.5
C4—C5—C6	107.6 (2)	H11B—C11—H11C	109.5
C4—C5—Cl5	127.83 (19)	O13—C12—C11	115 (3)
C6—C5—Cl5	124.30 (18)	O13—C12—H12A	109.7
C5—C6—C7	99.60 (18)	C11—C12—H12A	108.4
C5—C6—C1	107.42 (18)	O13—C12—H12B	109.3
C7—C6—C1	100.04 (19)	C11—C12—H12B	106.3
C5—C6—Cl6	115.98 (17)	H12A—C12—H12B	107.5
C7—C6—Cl6	116.93 (17)	C12^iii—O13—C12	110.6 (15)
C1—C6—Cl6	114.71 (16)
C8—C1—C2—C9	−0.2 (2)	C4—C3—C7—C6	51.21 (19)
C6—C1—C2—C9	−118.14 (19)	C2—C3—C7—C6	−58.12 (19)
C8—C1—C2—C3	118.2 (2)	Cl3—C3—C7—C6	177.35 (17)
C6—C1—C2—C3	0.2 (2)	C4—C3—C7—Cl72	−66.3 (2)
C9—C2—C3—C4	46.6 (3)	C2—C3—C7—Cl72	−175.61 (16)
C1—C2—C3—C4	−66.2 (2)	Cl3—C3—C7—Cl72	59.9 (2)
C9—C2—C3—C7	149.7 (2)	C4—C3—C7—Cl71	168.94 (16)
C1—C2—C3—C7	36.9 (2)	C2—C3—C7—Cl71	59.6 (2)
C9—C2—C3—Cl3	−84.0 (2)	Cl3—C3—C7—Cl71	−64.9 (2)
C1—C2—C3—Cl3	163.17 (16)	C5—C6—C7—C3	−51.29 (19)
C7—C3—C4—C5	−34.5 (2)	C1—C6—C7—C3	58.49 (19)
C2—C3—C4—C5	68.9 (2)	Cl6—C6—C7—C3	−177.04 (16)
Cl3—C3—C4—C5	−161.34 (17)	C5—C6—C7—Cl72	66.3 (2)
C7—C3—C4—Cl4	150.29 (18)	C1—C6—C7—Cl72	176.08 (16)
C2—C3—C4—Cl4	−106.3 (2)	Cl6—C6—C7—Cl72	−59.4 (2)
Cl3—C3—C4—Cl4	23.5 (3)	C5—C6—C7—Cl71	−168.49 (16)
C3—C4—C5—C6	0.2 (2)	C1—C6—C7—Cl71	−58.7 (2)
Cl4—C4—C5—C6	175.22 (18)	Cl6—C6—C7—Cl71	65.8 (2)
C3—C4—C5—Cl5	−174.04 (18)	C2—C1—C8—O2	−179.0 (2)
Cl4—C4—C5—Cl5	1.0 (3)	C6—C1—C8—O2	−67.6 (3)
C4—C5—C6—C7	34.2 (2)	C2—C1—C8—O1	−0.5 (2)
Cl5—C5—C6—C7	−151.32 (18)	C6—C1—C8—O1	110.9 (2)
C4—C5—C6—C1	−69.6 (2)	C1—C2—C9—O3	179.5 (3)
Cl5—C5—C6—C1	104.9 (2)	C3—C2—C9—O3	67.5 (3)
C4—C5—C6—Cl6	160.62 (17)	C1—C2—C9—O1	0.8 (2)
Cl5—C5—C6—Cl6	−24.9 (3)	C3—C2—C9—O1	−111.2 (2)
C8—C1—C6—C5	−46.0 (3)	O2—C8—O1—C9	179.6 (2)
C2—C1—C6—C5	66.2 (2)	C1—C8—O1—C9	1.0 (3)
C8—C1—C6—C7	−149.5 (2)	O3—C9—O1—C8	180.0 (2)
C2—C1—C6—C7	−37.2 (2)	C2—C9—O1—C8	−1.1 (3)
C8—C1—C6—Cl6	84.5 (2)	C11—C12—O13—C12^iii	−142 (5)
C2—C1—C6—Cl6	−163.23 (16)	C11^i—C12—O13—C12^iii	140 (5)

Symmetry codes: (i) −x+y, −x+1, z; (ii) −y+1, x−y+1, z; (iii) −x+2/3, −y+4/3, −z+1/3.

(III) bicyclo[2.2.1]hept-2-ene-endo-cis-5,6-dicarboxylic acid

Crystal data

C9H10O4	F(000) = 384
Mr = 182.17	Dx = 1.447 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 10.999 (2) Å	Cell parameters from 4135 reflections
b = 7.389 (1) Å	θ = 0–25°
c = 10.410 (2) Å	µ = 0.12 mm^−1
β = 98.75 (3)°	T = 173 K
V = 836.2 (2) Å^3	Block, colourless
Z = 4	0.5 × 0.1 × 0.1 mm

Data collection

Siemens CCD three-circle diffractometer	1707 independent reflections
Radiation source: fine-focus sealed tube	1304 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.062
ω scans	θmax = 26.4°, θmin = 1.9°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −13→13
Tmin = 0.945, Tmax = 0.989	k = −9→9
12009 measured reflections	l = −13→13

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.059	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.152	w = 1/[σ^2(Fo^2) + (0.0499P)^2 + 1.4698P] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max < 0.001
1707 reflections	Δρmax = 0.28 e Å^−3
121 parameters	Δρmin = −0.28 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.021 (4)

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.1539 (2)	0.7981 (4)	0.3321 (2)	0.0199 (6)
H1	0.1085	0.7814	0.2421	0.024*
C11	0.1000 (2)	0.6637 (4)	0.4161 (3)	0.0208 (6)
O11	0.04417 (18)	0.7081 (3)	0.50377 (19)	0.0280 (5)
O12	0.10889 (19)	0.4943 (3)	0.3781 (2)	0.0294 (5)
H12	0.0700	0.4266	0.4224	0.035*
C2	0.2941 (2)	0.7881 (4)	0.3204 (3)	0.0229 (6)
H2	0.3018	0.7641	0.2275	0.028*
C21	0.3751 (2)	0.6575 (4)	0.4033 (3)	0.0237 (6)
O21	0.36102 (19)	0.6043 (3)	0.51021 (19)	0.0344 (6)
O22	0.4710 (2)	0.6116 (4)	0.3478 (2)	0.0473 (7)
H22	0.5214	0.5535	0.4011	0.057*
C3	0.3360 (3)	0.9902 (4)	0.3534 (3)	0.0274 (7)
H3	0.4161	1.0272	0.3270	0.033*
C4	0.3234 (3)	1.0230 (4)	0.4945 (3)	0.0306 (7)
H4	0.3891	1.0365	0.5644	0.037*
C5	0.2050 (3)	1.0295 (4)	0.5032 (3)	0.0259 (6)
H5	0.1702	1.0495	0.5801	0.031*
C6	0.1348 (2)	0.9992 (4)	0.3684 (3)	0.0233 (6)
H6	0.0478	1.0431	0.3539	0.028*
C7	0.2215 (3)	1.0907 (4)	0.2860 (3)	0.0293 (7)
H7A	0.2268	1.2234	0.2989	0.035*
H7B	0.2014	1.0616	0.1924	0.035*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0189 (13)	0.0200 (14)	0.0201 (13)	0.0045 (11)	0.0003 (10)	−0.0004 (11)
C11	0.0186 (13)	0.0216 (14)	0.0208 (13)	0.0021 (11)	−0.0020 (10)	−0.0009 (11)
O11	0.0320 (11)	0.0264 (11)	0.0279 (11)	−0.0023 (9)	0.0121 (9)	−0.0040 (9)
O12	0.0363 (12)	0.0212 (11)	0.0337 (12)	0.0003 (9)	0.0146 (9)	−0.0025 (9)
C2	0.0222 (14)	0.0288 (16)	0.0183 (13)	0.0067 (12)	0.0046 (10)	0.0036 (11)
C21	0.0206 (13)	0.0280 (15)	0.0228 (14)	0.0061 (11)	0.0044 (11)	−0.0001 (12)
O21	0.0317 (12)	0.0473 (14)	0.0264 (11)	0.0187 (10)	0.0116 (9)	0.0140 (10)
O22	0.0417 (14)	0.0721 (19)	0.0319 (12)	0.0374 (13)	0.0182 (10)	0.0188 (12)
C3	0.0202 (14)	0.0297 (16)	0.0334 (16)	−0.0013 (12)	0.0071 (12)	0.0053 (13)
C4	0.0280 (16)	0.0292 (17)	0.0328 (16)	−0.0049 (13)	−0.0008 (12)	−0.0008 (13)
C5	0.0319 (16)	0.0199 (14)	0.0261 (15)	−0.0012 (12)	0.0050 (12)	−0.0036 (12)
C6	0.0213 (14)	0.0204 (14)	0.0285 (15)	0.0057 (11)	0.0044 (11)	0.0023 (11)
C7	0.0323 (16)	0.0257 (16)	0.0311 (16)	0.0057 (13)	0.0082 (12)	0.0076 (13)

Geometric parameters (Å, º)

C1—C11	1.503 (4)	O22—H22	0.8400
C1—C6	1.555 (4)	C3—C4	1.516 (4)
C1—C2	1.567 (4)	C3—C7	1.536 (4)
C1—H1	1.0000	C3—H3	1.0000
C11—O11	1.220 (3)	C4—C5	1.320 (4)
C11—O12	1.320 (3)	C4—H4	0.9500
O12—H12	0.8400	C5—C6	1.511 (4)
C2—C21	1.495 (4)	C5—H5	0.9500
C2—C3	1.585 (4)	C6—C7	1.533 (4)
C2—H2	1.0000	C6—H6	1.0000
C21—O21	1.213 (3)	C7—H7A	0.9900
C21—O22	1.322 (3)	C7—H7B	0.9900
C11—C1—C6	114.2 (2)	C7—C3—C2	99.5 (2)
C11—C1—C2	119.6 (2)	C4—C3—H3	115.9
C6—C1—C2	103.6 (2)	C7—C3—H3	115.9
C11—C1—H1	106.2	C2—C3—H3	115.9
C6—C1—H1	106.2	C5—C4—C3	108.0 (3)
C2—C1—H1	106.2	C5—C4—H4	126.0
O11—C11—O12	123.2 (3)	C3—C4—H4	126.0
O11—C11—C1	123.0 (2)	C4—C5—C6	107.5 (3)
O12—C11—C1	113.5 (2)	C4—C5—H5	126.2
C11—O12—H12	109.5	C6—C5—H5	126.2
C21—C2—C1	119.5 (2)	C5—C6—C7	100.4 (2)
C21—C2—C3	110.8 (2)	C5—C6—C1	107.3 (2)
C1—C2—C3	101.3 (2)	C7—C6—C1	99.6 (2)
C21—C2—H2	108.2	C5—C6—H6	115.7
C1—C2—H2	108.2	C7—C6—H6	115.7
C3—C2—H2	108.2	C1—C6—H6	115.7
O21—C21—O22	122.7 (3)	C6—C7—C3	93.9 (2)
O21—C21—C2	126.2 (2)	C6—C7—H7A	112.9
O22—C21—C2	111.0 (2)	C3—C7—H7A	112.9
C21—O22—H22	109.5	C6—C7—H7B	112.9
C4—C3—C7	100.1 (2)	C3—C7—H7B	112.9
C4—C3—C2	107.1 (2)	H7A—C7—H7B	110.4
C6—C1—C11—O11	1.3 (4)	C1—C2—C3—C7	−37.5 (2)
C2—C1—C11—O11	124.7 (3)	C7—C3—C4—C5	32.6 (3)
C6—C1—C11—O12	175.2 (2)	C2—C3—C4—C5	−70.8 (3)
C2—C1—C11—O12	−61.3 (3)	C3—C4—C5—C6	0.6 (3)
C11—C1—C2—C21	−6.2 (4)	C4—C5—C6—C7	−33.7 (3)
C6—C1—C2—C21	122.3 (3)	C4—C5—C6—C1	70.0 (3)
C11—C1—C2—C3	−128.2 (2)	C11—C1—C6—C5	64.6 (3)
C6—C1—C2—C3	0.3 (2)	C2—C1—C6—C5	−67.2 (3)
C1—C2—C21—O21	−29.4 (4)	C11—C1—C6—C7	168.8 (2)
C3—C2—C21—O21	87.7 (4)	C2—C1—C6—C7	37.0 (3)
C1—C2—C21—O22	154.0 (3)	C5—C6—C7—C3	49.9 (3)
C3—C2—C21—O22	−88.9 (3)	C1—C6—C7—C3	−59.9 (2)
C21—C2—C3—C4	−61.5 (3)	C4—C3—C7—C6	−49.3 (3)
C1—C2—C3—C4	66.3 (2)	C2—C3—C7—C6	60.1 (2)
C21—C2—C3—C7	−165.3 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O12—H12···O11^i	0.84	1.86	2.685 (3)	168
O22—H22···O21^ii	0.84	1.88	2.704 (3)	168

Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1, −y+1, −z+1.

(IVa) 1,2,3,4,7,7-hexachlorobicyclo[2.2.1]hept-2-ene-endo-cis-5,6-dicarboxylic acid

Crystal data

C9H4Cl6O4	F(000) = 384
Mr = 388.82	Dx = 1.869 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
a = 7.499 (1) Å	Cell parameters from 511 reflections
b = 7.924 (2) Å	θ = 1–25°
c = 11.873 (2) Å	µ = 1.25 mm^−1
β = 101.65 (1)°	T = 173 K
V = 691.0 (2) Å^3	Block, colourless
Z = 2	0.40 × 0.30 × 0.15 mm

Data collection

Siemens CCD three-circle diffractometer	3424 independent reflections
Radiation source: fine-focus sealed tube	3293 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.025
ω scans	θmax = 28.3°, θmin = 1.8°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −9→9
Tmin = 0.636, Tmax = 0.835	k = −10→10
19175 measured reflections	l = −15→15

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.019	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.048	w = 1/[σ^2(Fo^2) + (0.03P)^2 + 0.0924P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max = 0.001
3424 reflections	Δρmax = 0.28 e Å^−3
180 parameters	Δρmin = −0.21 e Å^−3
1 restraint	Absolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.02 (4)

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.69443 (18)	0.56656 (19)	0.66518 (12)	0.0136 (3)
H1	0.5763	0.5043	0.6443	0.016*
C11	0.8403 (2)	0.45674 (19)	0.62955 (13)	0.0157 (3)
O11	0.99048 (15)	0.42735 (15)	0.68550 (9)	0.0197 (2)
O12	0.77577 (16)	0.39949 (16)	0.52437 (10)	0.0242 (3)
H12	0.854 (3)	0.356 (3)	0.500 (2)	0.034 (6)*
C2	0.66776 (19)	0.74293 (18)	0.60301 (12)	0.0147 (3)
H2	0.5418	0.7502	0.5554	0.018*
C21	0.8045 (2)	0.78274 (19)	0.52874 (14)	0.0164 (3)
O21	0.96690 (15)	0.75069 (17)	0.55919 (11)	0.0253 (3)
O22	0.73263 (16)	0.85559 (18)	0.43038 (10)	0.0252 (3)
H22	0.815 (4)	0.866 (4)	0.394 (2)	0.055 (8)*
C3	0.6853 (2)	0.86596 (19)	0.70806 (13)	0.0169 (3)
Cl3	0.59753 (6)	1.06861 (5)	0.67095 (4)	0.02737 (9)
C4	0.8791 (2)	0.8599 (2)	0.77924 (13)	0.0179 (3)
Cl4	1.03082 (6)	1.02032 (5)	0.78540 (4)	0.02851 (10)
C5	0.90148 (19)	0.7098 (2)	0.83183 (12)	0.0177 (3)
Cl5	1.08377 (5)	0.63452 (6)	0.92641 (3)	0.02633 (9)
C6	0.7233 (2)	0.61224 (19)	0.79471 (13)	0.0163 (3)
Cl6	0.68870 (6)	0.44331 (5)	0.88242 (4)	0.02736 (9)
C7	0.5867 (2)	0.7625 (2)	0.78891 (13)	0.0181 (3)
Cl71	0.35827 (5)	0.70969 (5)	0.72692 (3)	0.02249 (9)
Cl72	0.58781 (6)	0.86019 (6)	0.92252 (4)	0.02939 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0126 (6)	0.0134 (6)	0.0160 (6)	−0.0002 (5)	0.0055 (5)	−0.0003 (5)
C11	0.0181 (7)	0.0121 (6)	0.0189 (7)	−0.0018 (5)	0.0083 (6)	−0.0005 (6)
O11	0.0187 (5)	0.0206 (5)	0.0202 (5)	0.0040 (5)	0.0049 (4)	0.0004 (5)
O12	0.0159 (5)	0.0322 (7)	0.0244 (6)	0.0045 (5)	0.0039 (5)	−0.0116 (5)
C2	0.0140 (6)	0.0144 (7)	0.0166 (7)	0.0002 (5)	0.0048 (5)	0.0006 (5)
C21	0.0174 (7)	0.0144 (6)	0.0180 (7)	−0.0009 (5)	0.0052 (5)	0.0022 (5)
O21	0.0151 (5)	0.0350 (7)	0.0268 (6)	0.0003 (5)	0.0068 (4)	0.0113 (5)
O22	0.0192 (5)	0.0369 (7)	0.0204 (6)	0.0022 (5)	0.0059 (5)	0.0131 (5)
C3	0.0169 (7)	0.0130 (6)	0.0212 (7)	0.0006 (5)	0.0049 (6)	−0.0010 (6)
Cl3	0.0289 (2)	0.01399 (17)	0.0380 (2)	0.00485 (15)	0.00408 (17)	−0.00003 (16)
C4	0.0159 (7)	0.0182 (7)	0.0201 (7)	−0.0022 (6)	0.0046 (5)	−0.0040 (6)
Cl4	0.02409 (19)	0.02241 (18)	0.0388 (2)	−0.00978 (15)	0.00585 (16)	−0.00508 (17)
C5	0.0169 (7)	0.0217 (7)	0.0152 (6)	0.0001 (6)	0.0045 (5)	−0.0015 (6)
Cl5	0.02127 (17)	0.0369 (2)	0.01900 (18)	0.00374 (17)	−0.00037 (14)	0.00260 (16)
C6	0.0181 (7)	0.0160 (7)	0.0164 (6)	−0.0005 (6)	0.0075 (5)	0.0015 (5)
Cl6	0.0347 (2)	0.02510 (19)	0.0254 (2)	−0.00138 (17)	0.01352 (16)	0.00918 (17)
C7	0.0173 (7)	0.0201 (7)	0.0184 (7)	−0.0006 (6)	0.0073 (6)	−0.0042 (6)
Cl71	0.01438 (15)	0.02752 (19)	0.02752 (19)	−0.00098 (14)	0.00888 (13)	−0.00406 (16)
Cl72	0.0298 (2)	0.0371 (2)	0.0242 (2)	−0.00039 (18)	0.01248 (16)	−0.01302 (18)

Geometric parameters (Å, º)

C1—C11	1.523 (2)	O22—H22	0.83 (3)
C1—C6	1.552 (2)	C3—C4	1.527 (2)
C1—C2	1.574 (2)	C3—C7	1.558 (2)
C1—H1	1.0000	C3—Cl3	1.7576 (16)
C11—O11	1.2087 (19)	C4—C5	1.338 (2)
C11—O12	1.3250 (19)	C4—Cl4	1.6978 (16)
O12—H12	0.79 (2)	C5—C6	1.530 (2)
C2—C21	1.515 (2)	C5—Cl5	1.6928 (15)
C2—C3	1.568 (2)	C6—C7	1.563 (2)
C2—H2	1.0000	C6—Cl6	1.7471 (16)
C21—O21	1.2249 (19)	C7—Cl72	1.7635 (16)
C21—O22	1.3165 (19)	C7—Cl71	1.7725 (16)
C11—C1—C6	116.37 (12)	C7—C3—C2	100.90 (12)
C11—C1—C2	114.03 (11)	C4—C3—Cl3	115.71 (11)
C6—C1—C2	103.69 (11)	C7—C3—Cl3	115.77 (11)
C11—C1—H1	107.4	C2—C3—Cl3	113.69 (10)
C6—C1—H1	107.4	C5—C4—C3	107.57 (13)
C2—C1—H1	107.4	C5—C4—Cl4	128.72 (12)
O11—C11—O12	125.07 (14)	C3—C4—Cl4	123.71 (12)
O11—C11—C1	126.80 (13)	C4—C5—C6	107.14 (13)
O12—C11—C1	108.12 (12)	C4—C5—Cl5	129.14 (12)
C11—O12—H12	109.8 (17)	C6—C5—Cl5	123.69 (12)
C21—C2—C3	112.07 (12)	C5—C6—C1	110.01 (12)
C21—C2—C1	114.90 (12)	C5—C6—C7	98.88 (12)
C3—C2—C1	101.35 (11)	C1—C6—C7	100.08 (12)
C21—C2—H2	109.4	C5—C6—Cl6	116.20 (11)
C3—C2—H2	109.4	C1—C6—Cl6	113.84 (11)
C1—C2—H2	109.4	C7—C6—Cl6	115.79 (10)
O21—C21—O22	123.87 (14)	C3—C7—C6	92.27 (11)
O21—C21—C2	122.31 (14)	C3—C7—Cl72	114.00 (11)
O22—C21—C2	113.81 (13)	C6—C7—Cl72	114.25 (11)
C21—O22—H22	107 (2)	C3—C7—Cl71	114.05 (11)
C4—C3—C7	99.17 (12)	C6—C7—Cl71	114.08 (11)
C4—C3—C2	109.79 (12)	Cl72—C7—Cl71	107.81 (8)
C6—C1—C11—O11	−14.7 (2)	Cl5—C5—C6—C1	−113.98 (13)
C2—C1—C11—O11	105.94 (17)	C4—C5—C6—C7	−36.11 (15)
C6—C1—C11—O12	166.21 (12)	Cl5—C5—C6—C7	141.81 (12)
C2—C1—C11—O12	−73.11 (16)	C4—C5—C6—Cl6	−160.70 (11)
C11—C1—C2—C21	−6.57 (18)	Cl5—C5—C6—Cl6	17.22 (17)
C6—C1—C2—C21	120.97 (13)	C11—C1—C6—C5	60.22 (17)
C11—C1—C2—C3	−127.61 (12)	C2—C1—C6—C5	−65.85 (14)
C6—C1—C2—C3	−0.08 (13)	C11—C1—C6—C7	163.61 (12)
C3—C2—C21—O21	73.26 (19)	C2—C1—C6—C7	37.55 (13)
C1—C2—C21—O21	−41.7 (2)	C11—C1—C6—Cl6	−72.21 (14)
C3—C2—C21—O22	−106.09 (15)	C2—C1—C6—Cl6	161.72 (9)
C1—C2—C21—O22	138.93 (14)	C4—C3—C7—C6	−52.81 (13)
C21—C2—C3—C4	−56.69 (16)	C2—C3—C7—C6	59.55 (12)
C1—C2—C3—C4	66.32 (14)	Cl3—C3—C7—C6	−177.27 (10)
C21—C2—C3—C7	−160.69 (12)	C4—C3—C7—Cl72	65.07 (13)
C1—C2—C3—C7	−37.68 (13)	C2—C3—C7—Cl72	177.42 (10)
C21—C2—C3—Cl3	74.70 (14)	Cl3—C3—C7—Cl72	−59.40 (14)
C1—C2—C3—Cl3	−162.29 (10)	C4—C3—C7—Cl71	−170.51 (10)
C7—C3—C4—C5	34.81 (15)	C2—C3—C7—Cl71	−58.15 (13)
C2—C3—C4—C5	−70.36 (16)	Cl3—C3—C7—Cl71	65.03 (14)
Cl3—C3—C4—C5	159.32 (12)	C5—C6—C7—C3	53.28 (12)
C7—C3—C4—Cl4	−145.45 (12)	C1—C6—C7—C3	−59.02 (12)
C2—C3—C4—Cl4	109.39 (14)	Cl6—C6—C7—C3	178.16 (10)
Cl3—C3—C4—Cl4	−20.94 (18)	C5—C6—C7—Cl72	−64.38 (13)
C3—C4—C5—C6	0.89 (17)	C1—C6—C7—Cl72	−176.68 (10)
Cl4—C4—C5—C6	−178.83 (12)	Cl6—C6—C7—Cl72	60.50 (14)
C3—C4—C5—Cl5	−176.88 (12)	C5—C6—C7—Cl71	170.95 (10)
Cl4—C4—C5—Cl5	3.4 (2)	C1—C6—C7—Cl71	58.65 (13)
C4—C5—C6—C1	68.10 (16)	Cl6—C6—C7—Cl71	−64.16 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O12—H12···O21^i	0.79 (2)	1.83 (3)	2.6214 (17)	179 (3)
O22—H22···O11^ii	0.83 (3)	1.95 (3)	2.7716 (17)	171 (3)

Symmetry codes: (i) −x+2, y−1/2, −z+1; (ii) −x+2, y+1/2, −z+1.

(IVb) 1,2,3,4,7,7-hexachlorobicyclo[2.2.1]hept-2-ene-endo-cis-5,6-dicarboxylic acid

Crystal data

C9H4Cl6O4	F(000) = 1536
Mr = 388.82	Dx = 1.814 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 8.443 (1) Å	Cell parameters from 8192 reflections
b = 24.809 (1) Å	θ = 1–25°
c = 13.594 (1) Å	µ = 1.21 mm^−1
β = 90.38 (1)°	T = 173 K
V = 2847.4 (4) Å^3	Block, colourless
Z = 8	0.5 × 0.4 × 0.4 mm

Data collection

Siemens CCD three-circle diffractometer	7069 independent reflections
Radiation source: fine-focus sealed tube	6477 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
ω scans	θmax = 28.3°, θmin = 1.7°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −11→11
Tmin = 0.583, Tmax = 0.643	k = −33→33
61228 measured reflections	l = −18→18

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.026	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.061	H atoms treated by a mixture of independent and constrained refinement
S = 1.14	w = 1/[σ^2(Fo^2) + (0.0212P)^2 + 2.1579P] where P = (Fo^2 + 2Fc^2)/3
7069 reflections	(Δ/σ)max = 0.002
359 parameters	Δρmax = 0.35 e Å^−3
0 restraints	Δρmin = −0.27 e Å^−3

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.40303 (17)	0.57589 (6)	0.05060 (10)	0.0152 (3)
H1	0.3967	0.5592	−0.0163	0.018*
C11	0.31014 (19)	0.54093 (6)	0.12113 (11)	0.0183 (3)
O11	0.20251 (15)	0.55721 (5)	0.17186 (10)	0.0281 (3)
O12	0.36090 (16)	0.49070 (5)	0.12002 (9)	0.0266 (3)
H12	0.312 (4)	0.4732 (12)	0.158 (2)	0.065 (9)*
C2	0.58295 (18)	0.58333 (6)	0.07849 (11)	0.0164 (3)
H2	0.6469	0.5730	0.0198	0.020*
C21	0.64166 (19)	0.55000 (6)	0.16492 (11)	0.0199 (3)
O21	0.60277 (16)	0.55752 (5)	0.25014 (8)	0.0289 (3)
O22	0.73663 (17)	0.51146 (6)	0.13545 (10)	0.0319 (3)
H22	0.761 (3)	0.4947 (12)	0.180 (2)	0.062 (9)*
C3	0.59588 (17)	0.64548 (6)	0.09100 (11)	0.0161 (3)
Cl3	0.79204 (5)	0.668329 (19)	0.09327 (3)	0.02970 (9)
C4	0.49067 (18)	0.66525 (6)	0.17445 (11)	0.0178 (3)
Cl4	0.56021 (5)	0.692073 (19)	0.28104 (3)	0.03112 (10)
C5	0.34005 (18)	0.66042 (6)	0.14541 (11)	0.0165 (3)
Cl5	0.17543 (5)	0.681273 (17)	0.20501 (3)	0.02577 (9)
C6	0.34183 (17)	0.63490 (6)	0.04291 (10)	0.0142 (3)
Cl6	0.16874 (5)	0.641385 (16)	−0.02796 (3)	0.02392 (8)
C7	0.49143 (18)	0.66422 (6)	0.00175 (11)	0.0154 (3)
Cl71	0.55830 (5)	0.640423 (15)	−0.11362 (3)	0.02192 (8)
Cl72	0.46621 (5)	0.734510 (15)	−0.00749 (3)	0.02487 (9)
C1A	0.90607 (17)	0.57664 (6)	0.58458 (11)	0.0158 (3)
H1A	0.8400	0.5626	0.5289	0.019*
C11A	0.85269 (19)	0.54735 (6)	0.67609 (11)	0.0200 (3)
O11A	0.78471 (15)	0.56857 (5)	0.74461 (9)	0.0263 (3)
O12A	0.88191 (17)	0.49534 (5)	0.66866 (10)	0.0309 (3)
H12A	0.854 (3)	0.4793 (12)	0.719 (2)	0.063 (9)*
C2A	1.08377 (17)	0.56819 (6)	0.55473 (10)	0.0154 (3)
H2A	1.0887	0.5480	0.4912	0.019*
C21A	1.18283 (19)	0.53924 (6)	0.63230 (11)	0.0187 (3)
O21A	1.17476 (17)	0.55117 (5)	0.71922 (9)	0.0306 (3)
O22A	1.27283 (15)	0.50093 (5)	0.59729 (9)	0.0262 (3)
H22A	1.322 (4)	0.4843 (14)	0.648 (3)	0.084 (11)*
C3A	1.14044 (17)	0.62763 (6)	0.53850 (11)	0.0157 (3)
Cl3A	1.31328 (5)	0.632293 (17)	0.46804 (3)	0.02498 (8)
C4A	1.14115 (18)	0.65700 (6)	0.63701 (11)	0.0172 (3)
Cl4A	1.30844 (5)	0.674789 (18)	0.69863 (3)	0.02864 (9)
C5A	0.99106 (18)	0.66355 (6)	0.66446 (11)	0.0173 (3)
Cl5A	0.92267 (5)	0.693265 (17)	0.76826 (3)	0.02881 (9)
C6A	0.88620 (17)	0.63890 (6)	0.58465 (11)	0.0162 (3)
Cl6A	0.68949 (5)	0.660605 (19)	0.58116 (3)	0.02991 (9)
C7A	0.98846 (18)	0.65370 (6)	0.49272 (11)	0.0172 (3)
Cl73	0.92290 (5)	0.623165 (17)	0.38217 (3)	0.02441 (8)
Cl74	1.00832 (5)	0.723432 (16)	0.47172 (3)	0.02732 (9)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0193 (7)	0.0128 (6)	0.0135 (6)	−0.0003 (5)	0.0014 (5)	0.0017 (5)
C11	0.0235 (7)	0.0140 (7)	0.0173 (7)	−0.0020 (5)	0.0010 (6)	0.0021 (5)
O11	0.0306 (6)	0.0190 (6)	0.0349 (7)	0.0026 (5)	0.0149 (5)	0.0077 (5)
O12	0.0400 (7)	0.0136 (5)	0.0263 (6)	0.0008 (5)	0.0127 (5)	0.0044 (5)
C2	0.0185 (7)	0.0166 (7)	0.0141 (6)	0.0038 (5)	0.0016 (5)	0.0023 (5)
C21	0.0215 (7)	0.0206 (7)	0.0176 (7)	0.0038 (6)	−0.0015 (6)	0.0036 (6)
O21	0.0384 (7)	0.0317 (7)	0.0167 (5)	0.0122 (5)	0.0007 (5)	0.0049 (5)
O22	0.0425 (8)	0.0321 (7)	0.0212 (6)	0.0215 (6)	−0.0010 (5)	0.0060 (5)
C3	0.0131 (6)	0.0185 (7)	0.0168 (7)	−0.0007 (5)	0.0011 (5)	0.0005 (5)
Cl3	0.01599 (18)	0.0381 (2)	0.0350 (2)	−0.00718 (16)	0.00140 (15)	−0.00055 (18)
C4	0.0212 (7)	0.0175 (7)	0.0148 (7)	−0.0006 (6)	0.0014 (5)	−0.0018 (5)
Cl4	0.0346 (2)	0.0387 (2)	0.02006 (18)	−0.00542 (18)	−0.00291 (16)	−0.01031 (16)
C5	0.0194 (7)	0.0145 (6)	0.0157 (7)	0.0014 (5)	0.0049 (5)	0.0003 (5)
Cl5	0.02282 (19)	0.02711 (19)	0.02753 (19)	0.00383 (15)	0.01106 (15)	−0.00218 (15)
C6	0.0145 (6)	0.0138 (6)	0.0143 (6)	−0.0005 (5)	0.0004 (5)	0.0019 (5)
Cl6	0.01877 (17)	0.02762 (19)	0.02530 (19)	0.00227 (14)	−0.00638 (14)	0.00333 (15)
C7	0.0186 (7)	0.0128 (6)	0.0150 (6)	0.0007 (5)	0.0031 (5)	0.0027 (5)
Cl71	0.02922 (19)	0.02264 (18)	0.01397 (16)	0.00442 (14)	0.00587 (14)	0.00377 (13)
Cl72	0.0339 (2)	0.01278 (16)	0.02804 (19)	−0.00005 (14)	0.00640 (16)	0.00511 (14)
C1A	0.0174 (7)	0.0151 (7)	0.0150 (6)	−0.0014 (5)	0.0009 (5)	0.0017 (5)
C11A	0.0234 (8)	0.0167 (7)	0.0200 (7)	−0.0032 (6)	0.0034 (6)	0.0013 (6)
O11A	0.0370 (7)	0.0181 (5)	0.0241 (6)	−0.0002 (5)	0.0143 (5)	0.0022 (4)
O12A	0.0508 (8)	0.0144 (5)	0.0277 (6)	−0.0004 (5)	0.0186 (6)	0.0031 (5)
C2A	0.0180 (7)	0.0144 (6)	0.0139 (6)	0.0013 (5)	0.0008 (5)	0.0020 (5)
C21A	0.0222 (7)	0.0144 (7)	0.0196 (7)	0.0023 (6)	−0.0009 (6)	0.0022 (5)
O21A	0.0481 (8)	0.0257 (6)	0.0178 (6)	0.0145 (6)	−0.0061 (5)	0.0014 (5)
O22A	0.0298 (6)	0.0259 (6)	0.0229 (6)	0.0124 (5)	−0.0014 (5)	0.0008 (5)
C3A	0.0146 (6)	0.0168 (7)	0.0156 (6)	0.0002 (5)	0.0015 (5)	0.0022 (5)
Cl3A	0.01929 (18)	0.0307 (2)	0.02506 (19)	−0.00258 (15)	0.00769 (14)	0.00209 (15)
C4A	0.0184 (7)	0.0160 (7)	0.0171 (7)	−0.0009 (5)	−0.0028 (5)	0.0016 (5)
Cl4A	0.02277 (19)	0.0360 (2)	0.0270 (2)	−0.00537 (16)	−0.00761 (15)	−0.00312 (17)
C5A	0.0220 (7)	0.0141 (6)	0.0157 (7)	0.0017 (5)	0.0011 (5)	0.0002 (5)
Cl5A	0.0350 (2)	0.0279 (2)	0.02368 (19)	0.00196 (17)	0.00765 (16)	−0.00799 (15)
C6A	0.0135 (6)	0.0171 (7)	0.0180 (7)	0.0018 (5)	0.0000 (5)	0.0032 (5)
Cl6A	0.01629 (18)	0.0357 (2)	0.0378 (2)	0.00892 (16)	−0.00020 (15)	0.00513 (18)
C7A	0.0196 (7)	0.0162 (7)	0.0157 (7)	0.0002 (5)	−0.0015 (5)	0.0043 (5)
Cl73	0.0293 (2)	0.02846 (19)	0.01538 (16)	−0.00220 (15)	−0.00557 (14)	0.00405 (14)
Cl74	0.0368 (2)	0.01635 (17)	0.0288 (2)	0.00087 (15)	−0.00033 (16)	0.00963 (15)

Geometric parameters (Å, º)

C1—C11	1.515 (2)	C1A—C11A	1.512 (2)
C1—C6	1.5558 (19)	C1A—C6A	1.554 (2)
C1—C2	1.574 (2)	C1A—C2A	1.571 (2)
C1—H1	1.0000	C1A—H1A	1.0000
C11—O11	1.214 (2)	C11A—O11A	1.2171 (19)
C11—O12	1.3180 (18)	C11A—O12A	1.3178 (19)
O12—H12	0.79 (3)	O12A—H12A	0.83 (3)
C2—C21	1.517 (2)	C2A—C21A	1.522 (2)
C2—C3	1.555 (2)	C2A—C3A	1.567 (2)
C2—H2	1.0000	C2A—H2A	1.0000
C21—O21	1.2206 (19)	C21A—O21A	1.2205 (19)
C21—O22	1.312 (2)	C21A—O22A	1.3085 (19)
O22—H22	0.76 (3)	O22A—H22A	0.90 (4)
C3—C4	1.526 (2)	C3A—C4A	1.524 (2)
C3—C7	1.566 (2)	C3A—C7A	1.562 (2)
C3—Cl3	1.7506 (15)	C3A—Cl3A	1.7547 (15)
C4—C5	1.334 (2)	C4A—C5A	1.333 (2)
C4—Cl4	1.6959 (15)	C4A—Cl4A	1.6958 (15)
C5—C6	1.531 (2)	C5A—C6A	1.524 (2)
C5—Cl5	1.6944 (15)	C5A—Cl5A	1.6967 (15)
C6—C7	1.564 (2)	C6A—C7A	1.567 (2)
C6—Cl6	1.7524 (15)	C6A—Cl6A	1.7463 (15)
C7—Cl72	1.7612 (15)	C7A—Cl74	1.7615 (15)
C7—Cl71	1.7717 (15)	C7A—Cl73	1.7686 (16)
C11—C1—C6	114.08 (12)	C11A—C1A—C6A	116.40 (12)
C11—C1—C2	114.67 (12)	C11A—C1A—C2A	116.03 (12)
C6—C1—C2	103.03 (11)	C6A—C1A—C2A	103.66 (11)
C11—C1—H1	108.2	C11A—C1A—H1A	106.7
C6—C1—H1	108.2	C6A—C1A—H1A	106.7
C2—C1—H1	108.2	C2A—C1A—H1A	106.7
O11—C11—O12	124.46 (14)	O11A—C11A—O12A	124.87 (14)
O11—C11—C1	124.17 (14)	O11A—C11A—C1A	124.50 (14)
O12—C11—C1	111.36 (13)	O12A—C11A—C1A	110.53 (13)
C11—O12—H12	110 (2)	C11A—O12A—H12A	111 (2)
C21—C2—C3	115.67 (13)	C21A—C2A—C3A	112.02 (12)
C21—C2—C1	115.62 (12)	C21A—C2A—C1A	113.92 (12)
C3—C2—C1	102.10 (11)	C3A—C2A—C1A	101.76 (11)
C21—C2—H2	107.7	C21A—C2A—H2A	109.6
C3—C2—H2	107.7	C3A—C2A—H2A	109.6
C1—C2—H2	107.7	C1A—C2A—H2A	109.6
O21—C21—O22	124.74 (14)	O21A—C21A—O22A	124.38 (14)
O21—C21—C2	124.27 (14)	O21A—C21A—C2A	121.49 (14)
O22—C21—C2	110.97 (13)	O22A—C21A—C2A	114.12 (13)
C21—O22—H22	109 (2)	C21A—O22A—H22A	108 (2)
C4—C3—C2	111.05 (12)	C4A—C3A—C7A	98.66 (11)
C4—C3—C7	98.80 (11)	C4A—C3A—C2A	109.00 (12)
C2—C3—C7	99.84 (11)	C7A—C3A—C2A	101.24 (11)
C4—C3—Cl3	115.98 (11)	C4A—C3A—Cl3A	116.71 (11)
C2—C3—Cl3	112.87 (10)	C7A—C3A—Cl3A	116.05 (10)
C7—C3—Cl3	116.45 (10)	C2A—C3A—Cl3A	113.25 (10)
C5—C4—C3	108.03 (13)	C5A—C4A—C3A	107.81 (13)
C5—C4—Cl4	127.72 (12)	C5A—C4A—Cl4A	128.31 (12)
C3—C4—Cl4	124.14 (11)	C3A—C4A—Cl4A	123.83 (11)
C4—C5—C6	106.94 (12)	C4A—C5A—C6A	107.49 (13)
C4—C5—Cl5	127.90 (12)	C4A—C5A—Cl5A	127.96 (12)
C6—C5—Cl5	125.08 (11)	C6A—C5A—Cl5A	124.55 (11)
C5—C6—C1	109.47 (11)	C5A—C6A—C1A	109.71 (12)
C5—C6—C7	98.40 (11)	C5A—C6A—C7A	98.81 (11)
C1—C6—C7	101.13 (11)	C1A—C6A—C7A	99.93 (11)
C5—C6—Cl6	116.70 (10)	C5A—C6A—Cl6A	116.32 (11)
C1—C6—Cl6	113.50 (10)	C1A—C6A—Cl6A	114.16 (10)
C7—C6—Cl6	115.66 (10)	C7A—C6A—Cl6A	115.79 (10)
C6—C7—C3	92.11 (10)	C3A—C7A—C6A	92.34 (11)
C6—C7—Cl72	112.86 (10)	C3A—C7A—Cl74	113.09 (10)
C3—C7—Cl72	114.61 (10)	C6A—C7A—Cl74	114.39 (11)
C6—C7—Cl71	115.12 (10)	C3A—C7A—Cl73	114.37 (11)
C3—C7—Cl71	113.95 (10)	C6A—C7A—Cl73	113.97 (10)
Cl72—C7—Cl71	107.81 (8)	Cl74—C7A—Cl73	108.21 (8)
C6—C1—C11—O11	−3.7 (2)	C6A—C1A—C11A—O11A	6.3 (2)
C2—C1—C11—O11	114.75 (17)	C2A—C1A—C11A—O11A	128.70 (17)
C6—C1—C11—O12	176.07 (13)	C6A—C1A—C11A—O12A	−177.29 (13)
C2—C1—C11—O12	−65.44 (17)	C2A—C1A—C11A—O12A	−54.89 (18)
C11—C1—C2—C21	6.24 (18)	C11A—C1A—C2A—C21A	−9.80 (18)
C6—C1—C2—C21	130.80 (13)	C6A—C1A—C2A—C21A	119.10 (13)
C11—C1—C2—C3	−120.21 (13)	C11A—C1A—C2A—C3A	−130.55 (13)
C6—C1—C2—C3	4.34 (13)	C6A—C1A—C2A—C3A	−1.66 (14)
C3—C2—C21—O21	49.8 (2)	C3A—C2A—C21A—O21A	70.11 (19)
C1—C2—C21—O21	−69.4 (2)	C1A—C2A—C21A—O21A	−44.7 (2)
C3—C2—C21—O22	−131.57 (15)	C3A—C2A—C21A—O22A	−110.82 (15)
C1—C2—C21—O22	109.20 (16)	C1A—C2A—C21A—O22A	134.35 (14)
C21—C2—C3—C4	−64.11 (16)	C21A—C2A—C3A—C4A	−54.88 (16)
C1—C2—C3—C4	62.31 (14)	C1A—C2A—C3A—C4A	67.19 (14)
C21—C2—C3—C7	−167.58 (12)	C21A—C2A—C3A—C7A	−158.22 (12)
C1—C2—C3—C7	−41.17 (13)	C1A—C2A—C3A—C7A	−36.15 (13)
C21—C2—C3—Cl3	68.10 (15)	C21A—C2A—C3A—Cl3A	76.84 (14)
C1—C2—C3—Cl3	−165.49 (9)	C1A—C2A—C3A—Cl3A	−161.09 (10)
C2—C3—C4—C5	−70.34 (16)	C7A—C3A—C4A—C5A	35.68 (15)
C7—C3—C4—C5	33.83 (15)	C2A—C3A—C4A—C5A	−69.45 (15)
Cl3—C3—C4—C5	159.06 (11)	Cl3A—C3A—C4A—C5A	160.70 (11)
C2—C3—C4—Cl4	113.23 (13)	C7A—C3A—C4A—Cl4A	−146.44 (11)
C7—C3—C4—Cl4	−142.60 (12)	C2A—C3A—C4A—Cl4A	108.43 (13)
Cl3—C3—C4—Cl4	−17.37 (18)	Cl3A—C3A—C4A—Cl4A	−21.42 (17)
C3—C4—C5—C6	2.37 (16)	C3A—C4A—C5A—C6A	−0.23 (16)
Cl4—C4—C5—C6	178.63 (11)	Cl4A—C4A—C5A—C6A	−177.99 (11)
C3—C4—C5—Cl5	−174.32 (11)	C3A—C4A—C5A—Cl5A	179.55 (11)
Cl4—C4—C5—Cl5	1.9 (2)	Cl4A—C4A—C5A—Cl5A	1.8 (2)
C4—C5—C6—C1	67.31 (15)	C4A—C5A—C6A—C1A	68.74 (15)
Cl5—C5—C6—C1	−115.88 (13)	Cl5A—C5A—C6A—C1A	−111.04 (13)
C4—C5—C6—C7	−37.71 (14)	C4A—C5A—C6A—C7A	−35.20 (15)
Cl5—C5—C6—C7	139.10 (11)	Cl5A—C5A—C6A—C7A	145.02 (11)
C4—C5—C6—Cl6	−162.06 (11)	C4A—C5A—C6A—Cl6A	−159.79 (11)
Cl5—C5—C6—Cl6	14.75 (17)	Cl5A—C5A—C6A—Cl6A	20.42 (17)
C11—C1—C6—C5	55.83 (16)	C11A—C1A—C6A—C5A	64.14 (16)
C2—C1—C6—C5	−69.11 (14)	C2A—C1A—C6A—C5A	−64.53 (14)
C11—C1—C6—C7	158.98 (12)	C11A—C1A—C6A—C7A	167.31 (12)
C2—C1—C6—C7	34.04 (13)	C2A—C1A—C6A—C7A	38.64 (13)
C11—C1—C6—Cl6	−76.50 (14)	C11A—C1A—C6A—Cl6A	−68.46 (16)
C2—C1—C6—Cl6	158.56 (9)	C2A—C1A—C6A—Cl6A	162.87 (10)
C5—C6—C7—C3	54.14 (12)	C4A—C3A—C7A—C6A	−52.92 (12)
C1—C6—C7—C3	−57.72 (12)	C2A—C3A—C7A—C6A	58.55 (12)
Cl6—C6—C7—C3	179.23 (10)	Cl3A—C3A—C7A—C6A	−178.41 (10)
C5—C6—C7—Cl72	−63.75 (12)	C4A—C3A—C7A—Cl74	64.90 (13)
C1—C6—C7—Cl72	−175.61 (10)	C2A—C3A—C7A—Cl74	176.37 (10)
Cl6—C6—C7—Cl72	61.34 (13)	Cl3A—C3A—C7A—Cl74	−60.59 (14)
C5—C6—C7—Cl71	171.91 (10)	C4A—C3A—C7A—Cl73	−170.62 (10)
C1—C6—C7—Cl71	60.04 (13)	C2A—C3A—C7A—Cl73	−59.14 (13)
Cl6—C6—C7—Cl71	−63.00 (13)	Cl3A—C3A—C7A—Cl73	63.90 (13)
C4—C3—C7—C6	−52.78 (12)	C5A—C6A—C7A—C3A	52.92 (12)
C2—C3—C7—C6	60.53 (12)	C1A—C6A—C7A—C3A	−59.01 (12)
Cl3—C3—C7—C6	−177.68 (10)	Cl6A—C6A—C7A—C3A	177.90 (10)
C4—C3—C7—Cl72	63.60 (13)	C5A—C6A—C7A—Cl74	−63.79 (13)
C2—C3—C7—Cl72	176.91 (10)	C1A—C6A—C7A—Cl74	−175.73 (10)
Cl3—C3—C7—Cl72	−61.30 (13)	Cl6A—C6A—C7A—Cl74	61.18 (14)
C4—C3—C7—Cl71	−171.54 (10)	C5A—C6A—C7A—Cl73	170.96 (10)
C2—C3—C7—Cl71	−58.24 (13)	C1A—C6A—C7A—Cl73	59.03 (13)
Cl3—C3—C7—Cl71	63.56 (13)	Cl6A—C6A—C7A—Cl73	−64.06 (13)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O12—H12···O11A^i	0.79 (3)	1.88 (3)	2.6627 (17)	174 (3)
O22—H22···O21A^ii	0.76 (3)	1.86 (3)	2.6186 (17)	175 (3)
O12A—H12A···O11^i	0.83 (3)	1.80 (3)	2.6320 (17)	178 (3)
O22A—H22A···O21^ii	0.90 (4)	1.84 (4)	2.7347 (17)	171 (3)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+2, −y+1, −z+1.

(V) ethyl 1,2,3,4,7,7-hexachloro-6-carboxybicyclo[2.2.1]hept-2-ene-endo-cis-5-carboxylate monohydrate

Crystal data

C11H8Cl6O4·H2O	Z = 2
Mr = 434.89	F(000) = 436
Triclinic, P1	Dx = 1.770 Mg m^−3
a = 8.616 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.281 (2) Å	Cell parameters from 2320 reflections
c = 10.460 (4) Å	θ = 1–20°
α = 100.53 (2)°	µ = 1.07 mm^−1
β = 94.00 (2)°	T = 173 K
γ = 95.06 (2)°	Plate, colourless
V = 816.0 (5) Å^3	0.25 × 0.20 × 0.10 mm

Data collection

Siemens CCD three-circle diffractometer	2886 independent reflections
Radiation source: fine-focus sealed tube	1709 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.086
ω scans	θmax = 25.0°, θmin = 2.0°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −10→10
Tmin = 0.776, Tmax = 0.901	k = −11→11
11168 measured reflections	l = −12→12

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.056	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.136	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0636P)^2] where P = (Fo^2 + 2Fc^2)/3
2886 reflections	(Δ/σ)max = 0.003
211 parameters	Δρmax = 0.47 e Å^−3
0 restraints	Δρmin = −0.45 e Å^−3

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.7769 (6)	0.6312 (5)	0.6060 (5)	0.0200 (12)
H1	0.7816	0.5234	0.5745	0.024*
C11	0.8086 (6)	0.7067 (6)	0.4925 (5)	0.0226 (13)
O11	0.9144 (4)	0.8017 (4)	0.4920 (4)	0.0329 (10)
O12	0.7029 (4)	0.6499 (4)	0.3930 (3)	0.0247 (9)
C12	0.7169 (7)	0.7031 (6)	0.2712 (6)	0.0393 (16)
H12A	0.6750	0.6237	0.1970	0.047*
H12B	0.8287	0.7289	0.2610	0.047*
C13	0.6282 (6)	0.8380 (6)	0.2681 (6)	0.0333 (15)
H13A	0.6398	0.8710	0.1852	0.050*
H13B	0.6707	0.9173	0.3405	0.050*
H13C	0.5171	0.8122	0.2766	0.050*
C2	0.6151 (6)	0.6492 (5)	0.6608 (5)	0.0195 (12)
H2	0.5517	0.5511	0.6465	0.023*
C21	0.5231 (6)	0.7582 (6)	0.6025 (5)	0.0217 (13)
O21	0.5761 (4)	0.8813 (4)	0.5974 (4)	0.0286 (9)
O22	0.3798 (4)	0.7006 (4)	0.5563 (4)	0.0297 (10)
H22	0.321 (8)	0.765 (7)	0.514 (7)	0.07 (2)*
C3	0.6633 (6)	0.7046 (6)	0.8105 (5)	0.0238 (13)
Cl3	0.50826 (17)	0.68412 (17)	0.90810 (14)	0.0354 (4)
C4	0.7522 (6)	0.8567 (6)	0.8313 (5)	0.0231 (13)
Cl4	0.68432 (18)	1.01342 (15)	0.90645 (15)	0.0387 (4)
C5	0.8900 (6)	0.8423 (6)	0.7829 (5)	0.0250 (13)
Cl5	1.03712 (18)	0.97470 (16)	0.78113 (16)	0.0413 (4)
C6	0.8944 (6)	0.6787 (6)	0.7277 (5)	0.0226 (13)
Cl6	1.08154 (16)	0.62094 (17)	0.70714 (15)	0.0377 (4)
C7	0.8036 (6)	0.6148 (6)	0.8307 (5)	0.0255 (13)
Cl71	0.89901 (17)	0.66000 (16)	0.98949 (14)	0.0346 (4)
Cl72	0.75705 (18)	0.42083 (15)	0.79200 (15)	0.0351 (4)
O1W	1.2286 (6)	0.8679 (5)	0.4347 (5)	0.0345 (11)
H1W	1.125 (8)	0.884 (7)	0.452 (7)	0.07 (3)*
H2W	1.267 (7)	0.941 (7)	0.431 (6)	0.04 (2)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.014 (3)	0.024 (3)	0.020 (3)	0.003 (2)	0.004 (2)	−0.001 (2)
C11	0.022 (3)	0.026 (3)	0.022 (3)	0.011 (3)	0.003 (3)	0.006 (3)
O11	0.020 (2)	0.042 (2)	0.037 (3)	−0.006 (2)	0.0017 (19)	0.014 (2)
O12	0.024 (2)	0.031 (2)	0.019 (2)	−0.0013 (17)	0.0002 (17)	0.0045 (17)
C12	0.044 (4)	0.043 (4)	0.029 (4)	−0.002 (3)	0.004 (3)	0.006 (3)
C13	0.021 (3)	0.045 (4)	0.032 (4)	0.002 (3)	0.001 (3)	0.005 (3)
C2	0.009 (3)	0.022 (3)	0.025 (3)	−0.001 (2)	−0.002 (2)	0.002 (2)
C21	0.025 (3)	0.027 (3)	0.012 (3)	0.002 (3)	0.003 (2)	−0.001 (2)
O21	0.020 (2)	0.022 (2)	0.044 (3)	0.0001 (17)	−0.0060 (19)	0.0114 (18)
O22	0.015 (2)	0.027 (2)	0.046 (3)	−0.0007 (18)	−0.0080 (19)	0.0076 (19)
C3	0.015 (3)	0.029 (3)	0.027 (3)	0.005 (2)	0.008 (3)	0.000 (3)
Cl3	0.0259 (9)	0.0499 (9)	0.0311 (9)	0.0034 (7)	0.0086 (7)	0.0078 (7)
C4	0.021 (3)	0.026 (3)	0.022 (3)	0.010 (3)	0.000 (3)	0.000 (2)
Cl4	0.0431 (10)	0.0302 (8)	0.0392 (10)	0.0161 (7)	−0.0023 (8)	−0.0063 (7)
C5	0.023 (3)	0.024 (3)	0.025 (3)	−0.002 (3)	−0.005 (3)	0.003 (2)
Cl5	0.0269 (9)	0.0368 (9)	0.0552 (11)	−0.0123 (7)	−0.0058 (8)	0.0069 (8)
C6	0.011 (3)	0.028 (3)	0.029 (3)	0.007 (2)	0.003 (2)	0.003 (3)
Cl6	0.0191 (8)	0.0492 (10)	0.0444 (10)	0.0150 (7)	−0.0003 (7)	0.0036 (8)
C7	0.023 (3)	0.026 (3)	0.025 (3)	0.006 (3)	−0.008 (3)	0.000 (2)
Cl71	0.0383 (10)	0.0380 (9)	0.0262 (9)	0.0109 (7)	−0.0096 (7)	0.0045 (7)
Cl72	0.0451 (10)	0.0217 (7)	0.0381 (9)	0.0055 (7)	−0.0064 (7)	0.0072 (7)
O1W	0.021 (3)	0.027 (3)	0.057 (3)	0.004 (2)	0.000 (2)	0.013 (2)

Geometric parameters (Å, º)

C1—C11	1.513 (7)	C21—O21	1.204 (6)
C1—C6	1.542 (7)	C21—O22	1.323 (6)
C1—C2	1.555 (7)	O22—H22	0.96 (7)
C1—H1	1.0000	C3—C4	1.517 (7)
C11—O11	1.212 (6)	C3—C7	1.551 (7)
C11—O12	1.332 (6)	C3—Cl3	1.754 (5)
O12—C12	1.457 (6)	C4—C5	1.331 (7)
C12—C13	1.528 (8)	C4—Cl4	1.695 (5)
C12—H12A	0.9900	C5—C6	1.528 (7)
C12—H12B	0.9900	C5—Cl5	1.689 (5)
C13—H13A	0.9800	C6—C7	1.547 (7)
C13—H13B	0.9800	C6—Cl6	1.758 (5)
C13—H13C	0.9800	C7—Cl71	1.762 (5)
C2—C21	1.524 (7)	C7—Cl72	1.775 (5)
C2—C3	1.571 (7)	O1W—H1W	0.94 (7)
C2—H2	1.0000	O1W—H2W	0.74 (6)
C11—C1—C6	115.6 (4)	O21—C21—C2	123.7 (5)
C11—C1—C2	115.9 (4)	O22—C21—C2	112.0 (4)
C6—C1—C2	103.8 (4)	C21—O22—H22	114 (4)
C11—C1—H1	107.0	C4—C3—C7	98.5 (4)
C6—C1—H1	107.0	C4—C3—C2	109.2 (4)
C2—C1—H1	107.0	C7—C3—C2	100.9 (4)
O11—C11—O12	125.8 (5)	C4—C3—Cl3	116.4 (4)
O11—C11—C1	125.4 (5)	C7—C3—Cl3	116.7 (4)
O12—C11—C1	108.8 (4)	C2—C3—Cl3	113.3 (4)
C11—O12—C12	117.7 (4)	C5—C4—C3	107.8 (4)
O12—C12—C13	111.5 (5)	C5—C4—Cl4	127.7 (4)
O12—C12—H12A	109.3	C3—C4—Cl4	124.5 (4)
C13—C12—H12A	109.3	C4—C5—C6	107.0 (5)
O12—C12—H12B	109.3	C4—C5—Cl5	128.4 (4)
C13—C12—H12B	109.3	C6—C5—Cl5	124.6 (4)
H12A—C12—H12B	108.0	C5—C6—C1	109.7 (4)
C12—C13—H13A	109.5	C5—C6—C7	98.5 (4)
C12—C13—H13B	109.5	C1—C6—C7	100.8 (4)
H13A—C13—H13B	109.5	C5—C6—Cl6	115.7 (4)
C12—C13—H13C	109.5	C1—C6—Cl6	114.5 (4)
H13A—C13—H13C	109.5	C7—C6—Cl6	115.7 (4)
H13B—C13—H13C	109.5	C6—C7—C3	92.7 (4)
C21—C2—C1	113.5 (4)	C6—C7—Cl71	113.7 (4)
C21—C2—C3	111.9 (4)	C3—C7—Cl71	113.6 (4)
C1—C2—C3	101.7 (4)	C6—C7—Cl72	114.0 (4)
C21—C2—H2	109.8	C3—C7—Cl72	114.5 (4)
C1—C2—H2	109.8	Cl71—C7—Cl72	107.9 (3)
C3—C2—H2	109.8	H1W—O1W—H2W	105 (6)
O21—C21—O22	124.3 (5)
C6—C1—C11—O11	−2.0 (7)	C4—C5—C6—C1	68.8 (5)
C2—C1—C11—O11	119.7 (6)	Cl5—C5—C6—C1	−111.8 (5)
C6—C1—C11—O12	177.0 (4)	C4—C5—C6—C7	−35.9 (5)
C2—C1—C11—O12	−61.3 (5)	Cl5—C5—C6—C7	143.5 (4)
O11—C11—O12—C12	1.6 (7)	C4—C5—C6—Cl6	−159.9 (4)
C1—C11—O12—C12	−177.3 (4)	Cl5—C5—C6—Cl6	19.5 (6)
C11—O12—C12—C13	−88.8 (6)	C11—C1—C6—C5	62.3 (5)
C11—C1—C2—C21	−7.9 (6)	C2—C1—C6—C5	−65.7 (5)
C6—C1—C2—C21	119.9 (4)	C11—C1—C6—C7	165.5 (4)
C11—C1—C2—C3	−128.3 (4)	C2—C1—C6—C7	37.5 (5)
C6—C1—C2—C3	−0.5 (5)	C11—C1—C6—Cl6	−69.7 (5)
C1—C2—C21—O21	−50.9 (7)	C2—C1—C6—Cl6	162.3 (3)
C3—C2—C21—O21	63.5 (6)	C5—C6—C7—C3	53.6 (4)
C1—C2—C21—O22	127.9 (5)	C1—C6—C7—C3	−58.4 (4)
C3—C2—C21—O22	−117.8 (5)	Cl6—C6—C7—C3	177.6 (4)
C21—C2—C3—C4	−54.9 (5)	C5—C6—C7—Cl71	−63.7 (4)
C1—C2—C3—C4	66.5 (5)	C1—C6—C7—Cl71	−175.7 (3)
C21—C2—C3—C7	−158.0 (4)	Cl6—C6—C7—Cl71	60.3 (5)
C1—C2—C3—C7	−36.6 (5)	C5—C6—C7—Cl72	172.0 (3)
C21—C2—C3—Cl3	76.5 (5)	C1—C6—C7—Cl72	60.0 (4)
C1—C2—C3—Cl3	−162.1 (3)	Cl6—C6—C7—Cl72	−64.1 (5)
C7—C3—C4—C5	35.2 (5)	C4—C3—C7—C6	−53.4 (4)
C2—C3—C4—C5	−69.5 (5)	C2—C3—C7—C6	58.1 (4)
Cl3—C3—C4—C5	160.8 (4)	Cl3—C3—C7—C6	−178.7 (4)
C7—C3—C4—Cl4	−143.6 (4)	C4—C3—C7—Cl71	63.9 (5)
C2—C3—C4—Cl4	111.7 (5)	C2—C3—C7—Cl71	175.5 (3)
Cl3—C3—C4—Cl4	−18.1 (6)	Cl3—C3—C7—Cl71	−61.4 (5)
C3—C4—C5—C6	0.4 (6)	C4—C3—C7—Cl72	−171.4 (4)
Cl4—C4—C5—C6	179.1 (4)	C2—C3—C7—Cl72	−59.9 (5)
C3—C4—C5—Cl5	−179.0 (4)	Cl3—C3—C7—Cl72	63.3 (5)
Cl4—C4—C5—Cl5	−0.3 (8)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O22—H22···O1W^i	0.96 (7)	1.60 (7)	2.564 (6)	176 (6)
O1W—H1W···O11	0.94 (7)	2.01 (7)	2.852 (6)	148 (6)
O1W—H2W···O21^ii	0.74 (6)	2.12 (6)	2.835 (6)	165 (7)

Symmetry codes: (i) x−1, y, z; (ii) −x+2, −y+2, −z+1.