4,7-Di­chloro­tri­cyclo­[3.1.1.0^3,6]­heptane-2-carboxyl­ic acid

The structure of the carboxyl­ic acid derivative of the new substituted open-cage system, 4,7-di­chloro­tri­cyclo­[3.1.1.0^3,6]­heptane-2-carboxyl­ic acid, C₈H₈Cl₂O₂, shows that the carboxyl C atom has close contacts with C atoms of the cage system. Hydro­gen bonds from the carboxyl­ic acid functional groups of adjoining mol­ecules form centrosymmetric dimers.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.040
• wR factor = 0.110
• Data-to-parameter ratio = 13.0

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



SHFSU_01  Alert C The absolute value of parameter shift to su ratio > 0.05
          Absolute value of the parameter shift to su ratio given   0.053
          Additional refinement cycles may be required.

PLAT_320  Alert C Check Hybridisation of  C(1)   in main residue          ?

PLAT_320  Alert C Check Hybridisation of  C(3)   in main residue          ?

PLAT_320  Alert C Check Hybridisation of  C(5)   in main residue          ?

PLAT_320  Alert C Check Hybridisation of  C(6)   in main residue          ?


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 5 Alert Level C = Please check

---

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SMART; data reduction: SHELXTL (Bruker, 2001); program(s) used to solve structure: SHELXTL; program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

4,7-dichlorotricyclo[3.1.1.0^3,6]heptane-2-carboxylic acid

Crystal data

C8H8Cl2O2	F(000) = 848
Mr = 207.04	Dx = 1.545 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 21.497 (7) Å	Cell parameters from 786 reflections
b = 9.036 (3) Å	θ = 2.3–28.1°
c = 10.084 (3) Å	µ = 0.68 mm^−1
β = 114.673 (6)°	T = 294 K
V = 1779.9 (10) Å^3	Irregular plate, colourless
Z = 8	0.42 × 0.40 × 0.10 mm

Data collection

Bruker SMART 1K CCD area-detector diffractometer	1822 independent reflections
Radiation source: fine-focus sealed tube	1512 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
φ and ω scans	θmax = 26.4°, θmin = 2.1°
Absorption correction: integration (Wuensch & Prewett, 1965)	h = −24→26
Tmin = 0.740, Tmax = 0.935	k = −11→6
5852 measured reflections	l = −12→9

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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.110	All H-atom parameters refined
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0521P)^2 + 1.6743P] where P = (Fo^2 + 2Fc^2)/3
1822 reflections	(Δ/σ)max = 0.053
140 parameters	Δρmax = 0.39 e Å^−3
0 restraints	Δρmin = −0.32 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
C	0.69894 (11)	0.3240 (2)	0.8074 (2)	0.0463 (5)
O1	0.67660 (9)	0.3515 (2)	0.90279 (18)	0.0651 (5)
H1O	0.698 (2)	0.329 (4)	0.979 (4)	0.098*
O2	0.75173 (9)	0.2508 (2)	0.83185 (18)	0.0691 (5)
C1	0.57922 (11)	0.3803 (2)	0.5909 (2)	0.0501 (5)
H1	0.5564 (13)	0.462 (3)	0.610 (3)	0.054 (6)*
C2	0.65817 (11)	0.3850 (2)	0.6576 (2)	0.0481 (5)
H2	0.6734 (12)	0.491 (3)	0.661 (2)	0.053 (6)*
C3	0.65920 (11)	0.3098 (2)	0.5222 (2)	0.0481 (5)
H3	0.6939 (12)	0.340 (3)	0.491 (3)	0.050 (6)*
C4	0.64305 (12)	0.1441 (2)	0.5147 (2)	0.0485 (5)
H4	0.6661 (11)	0.084 (2)	0.600 (2)	0.043 (5)*
Cl4	0.65773 (4)	0.06093 (9)	0.36914 (8)	0.0810 (3)
C5	0.56682 (12)	0.1774 (3)	0.4653 (2)	0.0506 (5)
H5	0.5357 (14)	0.118 (3)	0.397 (3)	0.062 (7)*
C6	0.58089 (12)	0.3426 (3)	0.4415 (2)	0.0534 (6)
H6	0.5604 (13)	0.397 (3)	0.360 (3)	0.057 (7)*
C7	0.55132 (11)	0.2249 (3)	0.5938 (3)	0.0510 (5)
H7	0.5703 (12)	0.166 (3)	0.685 (3)	0.048 (6)*
Cl7	0.46051 (3)	0.23276 (9)	0.53865 (9)	0.0782 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C	0.0440 (11)	0.0449 (10)	0.0419 (11)	−0.0037 (9)	0.0101 (9)	−0.0055 (8)
O1	0.0570 (10)	0.0853 (13)	0.0431 (9)	0.0195 (9)	0.0111 (7)	−0.0046 (8)
O2	0.0531 (10)	0.1012 (14)	0.0477 (9)	0.0232 (9)	0.0157 (8)	0.0024 (9)
C1	0.0481 (12)	0.0449 (11)	0.0468 (12)	0.0083 (9)	0.0096 (9)	0.0072 (9)
C2	0.0484 (12)	0.0389 (11)	0.0473 (11)	−0.0038 (9)	0.0104 (9)	0.0014 (8)
C3	0.0461 (11)	0.0529 (12)	0.0415 (11)	−0.0094 (9)	0.0143 (9)	0.0045 (9)
C4	0.0513 (12)	0.0486 (12)	0.0441 (11)	−0.0024 (10)	0.0186 (9)	−0.0032 (9)
Cl4	0.0805 (5)	0.0957 (5)	0.0758 (5)	−0.0176 (4)	0.0415 (4)	−0.0349 (4)
C5	0.0464 (12)	0.0514 (12)	0.0465 (12)	−0.0096 (10)	0.0120 (10)	−0.0008 (10)
C6	0.0512 (12)	0.0543 (13)	0.0420 (11)	−0.0021 (10)	0.0069 (10)	0.0141 (10)
C7	0.0406 (11)	0.0558 (13)	0.0531 (12)	0.0064 (9)	0.0162 (9)	0.0133 (10)
Cl7	0.0464 (4)	0.0873 (5)	0.1000 (6)	0.0056 (3)	0.0297 (4)	0.0200 (4)

Geometric parameters (Å, º)

C—O2	1.246 (3)	C3—C6	1.562 (3)
C—O1	1.266 (3)	C3—H3	0.96 (2)
C—C2	1.500 (3)	C4—C5	1.531 (3)
O1—H1O	0.74 (4)	C4—Cl4	1.791 (2)
C1—C7	1.532 (3)	C4—H4	0.96 (2)
C1—C2	1.543 (3)	C5—C7	1.527 (3)
C1—C6	1.559 (3)	C5—C6	1.561 (3)
C1—H1	0.95 (2)	C5—H5	0.91 (3)
C2—C3	1.533 (3)	C6—H6	0.90 (3)
C2—H2	1.01 (2)	C7—Cl7	1.794 (2)
C3—C4	1.532 (3)	C7—H7	0.99 (2)
O2—C—O1	123.8 (2)	C5—C4—Cl4	110.30 (16)
O2—C—C2	119.7 (2)	C3—C4—Cl4	109.66 (16)
O1—C—C2	116.5 (2)	C5—C4—H4	119.2 (13)
C—O1—H1O	118 (3)	C3—C4—H4	119.2 (13)
C7—C1—C2	112.65 (17)	Cl4—C4—H4	106.9 (13)
C7—C1—C6	89.15 (17)	C7—C5—C4	111.24 (18)
C2—C1—C6	87.86 (17)	C7—C5—C6	89.25 (18)
C7—C1—H1	118.0 (14)	C4—C5—C6	89.34 (17)
C2—C1—H1	117.2 (15)	C7—C5—H5	117.3 (16)
C6—C1—H1	126.0 (14)	C4—C5—H5	118.6 (17)
C—C2—C3	120.99 (19)	C6—C5—H5	125.0 (16)
C—C2—C1	120.21 (19)	C1—C6—C5	88.63 (16)
C3—C2—C1	91.24 (16)	C1—C6—C3	89.58 (16)
C—C2—H2	105.8 (14)	C5—C6—C3	88.56 (17)
C3—C2—H2	108.8 (13)	C1—C6—H6	124.0 (16)
C1—C2—H2	108.9 (14)	C5—C6—H6	127.8 (16)
C4—C3—C2	112.91 (17)	C3—C6—H6	126.2 (16)
C4—C3—C6	89.24 (16)	C5—C7—C1	90.89 (17)
C2—C3—C6	88.10 (17)	C5—C7—Cl7	110.04 (16)
C4—C3—H3	116.7 (14)	C1—C7—Cl7	110.01 (15)
C2—C3—H3	118.1 (14)	C5—C7—H7	119.0 (13)
C6—C3—H3	126.1 (14)	C1—C7—H7	119.7 (13)
C5—C4—C3	90.76 (17)	Cl7—C7—H7	106.4 (13)
O2—C—C2—C3	26.8 (3)	C7—C1—C6—C5	−10.76 (16)
O1—C—C2—C3	−153.2 (2)	C2—C1—C6—C5	101.94 (16)
O2—C—C2—C1	139.1 (2)	C7—C1—C6—C3	−99.32 (16)
O1—C—C2—C1	−40.9 (3)	C2—C1—C6—C3	13.38 (16)
C7—C1—C2—C	−52.9 (3)	C7—C5—C6—C1	10.79 (16)
C6—C1—C2—C	−141.1 (2)	C4—C5—C6—C1	−100.47 (16)
C7—C1—C2—C3	74.6 (2)	C7—C5—C6—C3	100.40 (17)
C6—C1—C2—C3	−13.64 (16)	C4—C5—C6—C3	−10.86 (17)
C—C2—C3—C4	52.1 (3)	C4—C3—C6—C1	99.49 (16)
C1—C2—C3—C4	−74.8 (2)	C2—C3—C6—C1	−13.46 (16)
C—C2—C3—C6	140.5 (2)	C4—C3—C6—C5	10.85 (17)
C1—C2—C3—C6	13.61 (16)	C2—C3—C6—C5	−102.10 (17)
C2—C3—C4—C5	76.6 (2)	C4—C5—C7—C1	78.0 (2)
C6—C3—C4—C5	−11.06 (17)	C6—C5—C7—C1	−10.98 (16)
C2—C3—C4—Cl4	−171.53 (15)	C4—C5—C7—Cl7	−170.28 (15)
C6—C3—C4—Cl4	100.85 (17)	C6—C5—C7—Cl7	100.73 (16)
C3—C4—C5—C7	−77.9 (2)	C2—C1—C7—C5	−76.3 (2)
Cl4—C4—C5—C7	170.80 (15)	C6—C1—C7—C5	10.99 (16)
C3—C4—C5—C6	11.07 (17)	C2—C1—C7—Cl7	171.93 (16)
Cl4—C4—C5—C6	−100.26 (17)	C6—C1—C7—Cl7	−100.74 (17)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1O···O2^i	0.74 (4)	1.90 (4)	2.636 (3)	173 (4)

Symmetry code: (i) −x+3/2, −y+1/2, −z+2.