(Z)-3,6-Diethynyl-3,6-di­hydroxy­cyclo­hexa-1,4-diene

In the title compound, C₁₀H₈O₂, the four symmetry-related mol­ecules are connected to each other through O—H...O hydrogen bonds to form a helical chain along the b axis. The interconnected system is further extended along the c axis through O—H...O hydrogen bonds to form a two-dimensional network. Unlike its trans isomer, no C—H...O or C—H...π interactions are observed in the crystal structure.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.059
• wR factor = 0.154
• Data-to-parameter ratio = 12.7

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT027_ALERT_3_B _diffrn_reflns_theta_full (too) Low ............      24.97 Deg.

Alert level C
PLAT026_ALERT_3_C Ratio Observed / Unique Reflections too Low ....         45 Perc.
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          6

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 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
   3 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 1999); software used to prepare material for publication: SHELXL97 and WinGX (Farrugia, 1999).

(Z)-3,6-Diethynyl-3,6-dihydroxycyclohexa-1,4-diene

Crystal data

C10H8O2	Dx = 1.158 Mg m^−3
Mr = 160.16	Melting point: 124-126 °C K
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 10.598 (2) Å	Cell parameters from 25 reflections
b = 6.2646 (10) Å	θ = 10–15°
c = 14.153 (3) Å	µ = 0.08 mm^−1
β = 102.06 (2)°	T = 293 K
V = 918.9 (3) Å^3	Plate, colourless
Z = 4	0.3 × 0.2 × 0.2 mm
F(000) = 336

Data collection

Enraf–Nonius CAD-4 diffractometer	730 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.048
Graphite monochromator	θmax = 25.0°, θmin = 2.9°
ω–2θ scans	h = 0→12
Absorption correction: ψ scan (North et al., 1968)	k = 0→7
Tmin = 0.941, Tmax = 0.989	l = −16→16
1712 measured reflections	2 standard reflections every 60 min
1617 independent reflections	intensity decay: none

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)] = 0.059	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.154	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0602P)^2] where P = (Fo^2 + 2Fc^2)/3
1617 reflections	(Δ/σ)max < 0.001
127 parameters	Δρmax = 0.29 e Å^−3
4 restraints	Δρmin = −0.19 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	0.7342 (3)	0.2621 (6)	0.7495 (3)	0.0520 (9)
C2	0.6918 (3)	0.0387 (6)	0.7243 (2)	0.0456 (9)
C3	0.6383 (3)	−0.0649 (6)	0.8033 (3)	0.0575 (10)
C4	0.6516 (4)	0.0164 (7)	0.8903 (3)	0.0661 (11)
C5	0.7126 (3)	0.2264 (7)	0.9197 (2)	0.0619 (11)
C6	0.7450 (4)	0.3448 (6)	0.8364 (3)	0.0620 (10)
C7	0.8007 (4)	−0.0879 (6)	0.7055 (2)	0.0589 (10)
C8	0.8867 (5)	−0.1847 (7)	0.6899 (3)	0.0927 (16)
C9	0.8314 (4)	0.2037 (6)	0.9943 (3)	0.0683 (11)
C10	0.9279 (4)	0.1899 (7)	1.0515 (3)	0.0918 (15)
O1	0.5881 (2)	0.0397 (4)	0.64040 (16)	0.0634 (8)
O2	0.6264 (3)	0.3535 (5)	0.96314 (18)	0.0969 (11)
H1	0.756 (3)	0.344 (4)	0.6977 (14)	0.062 (10)*
H1'	0.6133	0.0927	0.5947	0.14 (2)*
H2'	0.5604	0.3784	0.9228	0.15 (2)*
H3	0.597 (3)	−0.200 (2)	0.785 (2)	0.055 (10)*
H4	0.613 (3)	−0.065 (5)	0.935 (2)	0.078 (12)*
H6	0.763 (3)	0.4945 (14)	0.845 (2)	0.067 (12)*
H8	0.9560	−0.2628	0.6772	0.111*
H10	1.0048	0.1789	1.0970	0.110*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.058 (2)	0.052 (3)	0.046 (2)	−0.0053 (19)	0.0095 (18)	0.0053 (19)
C2	0.0437 (18)	0.062 (3)	0.0311 (17)	−0.0071 (18)	0.0069 (15)	0.0009 (17)
C3	0.057 (2)	0.062 (3)	0.053 (2)	−0.009 (2)	0.0110 (18)	0.004 (2)
C4	0.063 (2)	0.095 (3)	0.043 (2)	0.005 (2)	0.0173 (19)	0.016 (2)
C5	0.059 (2)	0.087 (3)	0.039 (2)	0.026 (2)	0.0079 (18)	−0.007 (2)
C6	0.077 (3)	0.053 (3)	0.052 (2)	0.011 (2)	0.0035 (19)	−0.005 (2)
C7	0.061 (2)	0.065 (3)	0.054 (2)	0.000 (2)	0.0185 (19)	−0.005 (2)
C8	0.086 (3)	0.092 (4)	0.108 (4)	0.014 (3)	0.036 (3)	−0.012 (3)
C9	0.073 (3)	0.084 (3)	0.046 (2)	0.030 (2)	0.007 (2)	−0.008 (2)
C10	0.080 (3)	0.113 (4)	0.074 (3)	0.032 (3)	−0.004 (2)	−0.011 (3)
O1	0.0512 (13)	0.099 (2)	0.0368 (13)	−0.0170 (15)	0.0023 (11)	0.0037 (14)
O2	0.0849 (19)	0.159 (3)	0.0422 (14)	0.067 (2)	0.0024 (14)	−0.0175 (17)

Geometric parameters (Å, º)

C1—C6	1.316 (5)	C5—O2	1.442 (4)
C1—C2	1.490 (5)	C5—C9	1.470 (5)
C1—H1	0.96 (2)	C5—C6	1.493 (5)
C2—O1	1.439 (4)	C6—H6	0.960 (12)
C2—C7	1.469 (5)	C7—C8	1.154 (5)
C2—C3	1.504 (4)	C8—H8	0.9300
C3—C4	1.312 (5)	C9—C10	1.168 (5)
C3—H3	0.963 (18)	C10—H10	0.9300
C4—C5	1.487 (5)	O1—H1'	0.8200
C4—H4	0.97 (3)	O2—H2'	0.8200
C6—C1—C2	123.8 (3)	O2—C5—C9	105.7 (3)
C6—C1—H1	120.9 (19)	O2—C5—C4	109.3 (3)
C2—C1—H1	115.2 (18)	C9—C5—C4	111.9 (3)
O1—C2—C7	110.3 (3)	O2—C5—C6	109.4 (3)
O1—C2—C1	109.5 (3)	C9—C5—C6	108.2 (3)
C7—C2—C1	110.0 (3)	C4—C5—C6	112.1 (3)
O1—C2—C3	105.9 (3)	C1—C6—C5	123.6 (4)
C7—C2—C3	109.5 (3)	C1—C6—H6	119 (2)
C1—C2—C3	111.6 (3)	C5—C6—H6	117 (2)
C4—C3—C2	123.2 (4)	C8—C7—C2	178.9 (4)
C4—C3—H3	123.0 (18)	C7—C8—H8	180.0
C2—C3—H3	113.8 (18)	C10—C9—C5	177.6 (5)
C3—C4—C5	124.1 (4)	C9—C10—H10	180.0
C3—C4—H4	115 (2)	C2—O1—H1'	109.5
C5—C4—H4	120 (2)	C5—O2—H2'	109.5
C6—C1—C2—O1	128.3 (3)	C3—C4—C5—O2	127.4 (4)
C6—C1—C2—C7	−110.4 (4)	C3—C4—C5—C9	−115.8 (4)
C6—C1—C2—C3	11.4 (5)	C3—C4—C5—C6	5.9 (5)
O1—C2—C3—C4	−131.7 (4)	C2—C1—C6—C5	−1.8 (6)
C7—C2—C3—C4	109.4 (4)	O2—C5—C6—C1	−128.7 (4)
C1—C2—C3—C4	−12.7 (5)	C9—C5—C6—C1	116.6 (4)
C2—C3—C4—C5	4.4 (6)	C4—C5—C6—C1	−7.2 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1′···O2^i	0.82	1.93	2.708 (3)	159
O2—H2′···O1^ii	0.82	1.93	2.699 (4)	157

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