5-Methoxy­tropolone

The title compound [systematic name: 2-hydr­oxy-5-meth­oxy-2,4,6-cyclo­hepta­trien-1-one], C₈H₈O₃, contains intra- and inter­molecular O—H...O hydrogen bonds, resulting in inversion-symmetry generated dimers. The crystal packing is consolidated by π–π, C—H...π and C—H...O inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 153 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.032
• wR factor = 0.081
• Data-to-parameter ratio = 12.0

checkCIF/PLATON results

No syntax errors found



Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.573     0.888
            Tmin(prime) and Tmax expected:      0.689     0.888
            RR(prime) =      0.832
            Please check that your absorption correction is appropriate.
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.96
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large .............       0.81
PLAT166_ALERT_4_C S.U's Given on Coordinates for calc-flagged ....         H1
PLAT480_ALERT_4_C Long H...A H-Bond Reported H5     ..  O1      ..       2.61 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H6     ..  C7      ..       2.89 Ang.

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   6 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
   3 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: CrystalClear (Rigaku, 1999); cell refinement: CrystalClear; data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: CrystalStructure.

2-hydroxy-5-methoxy-2,4,6-cycloheptatrien-1-one

Crystal data

C8H8O3	F(000) = 320.00
Mr = 152.15	Dx = 1.401 Mg m^−3
Monoclinic, P21/n	Cu Kα radiation, λ = 1.54187 Å
Hall symbol: -P 2yn	Cell parameters from 6341 reflections
a = 8.434 (2) Å	θ = 3.8–68.2°
b = 7.265 (2) Å	µ = 0.91 mm^−1
c = 12.308 (3) Å	T = 153 K
β = 106.976 (15)°	Prism, colourless
V = 721.3 (3) Å^3	0.38 × 0.19 × 0.13 mm
Z = 4

Data collection

Rigaku R-AXIS RAPID diffractometer	1169 reflections with F^2 > 2σ(F^2)
Detector resolution: 10.00 pixels mm^-1	Rint = 0.036
ω scans	θmax = 68.2°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −10→10
Tmin = 0.573, Tmax = 0.888	k = −7→8
6663 measured reflections	l = −14→13
1272 independent reflections

Refinement

Refinement on F^2	w = 1/[σ^2(Fo^2) + (0.03P)^2 + 0.1908P] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.032	(Δ/σ)max < 0.001
wR(F^2) = 0.081	Δρmax = 0.20 e Å^−3
S = 1.13	Δρmin = −0.14 e Å^−3
1272 reflections	Extinction correction: SHELXL97 (Sheldrick 1997)
106 parameters	Extinction coefficient: 0.0228 (14)
H atoms treated by a mixture of independent and constrained refinement

Special details

Geometry. ENTER SPECIAL DETAILS OF THE MOLECULAR GEOMETRY

Refinement. Refinement using reflections with F² > 3.0 σ(F²). The weighted R-factor(wR), goodness of fit (S) and R-factor (gt) are based on F, with F set to zero for negative F. The threshold expression of F² > 2.0 σ(F²) is used only for calculating R-factor (gt).

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

	x	y	z	Uiso*/Ueq
O1	0.96326 (12)	0.28586 (12)	0.51873 (9)	0.0395 (2)
O2	0.79034 (12)	0.56522 (12)	0.55310 (8)	0.0363 (2)
O3	0.46975 (11)	−0.07481 (12)	0.68237 (8)	0.0357 (2)
C1	0.84520 (14)	0.24571 (18)	0.55725 (11)	0.0282 (3)
C2	0.74411 (14)	0.39577 (17)	0.57767 (10)	0.0277 (3)
C3	0.60899 (14)	0.38932 (18)	0.61762 (11)	0.0304 (3)
C4	0.52560 (16)	0.24107 (18)	0.64977 (11)	0.0301 (3)
C5	0.56170 (14)	0.05797 (18)	0.65019 (10)	0.0284 (3)
C6	0.69469 (14)	−0.02170 (19)	0.61801 (10)	0.0291 (3)
C7	0.81423 (14)	0.05728 (18)	0.57964 (11)	0.0294 (3)
C8	0.33143 (18)	−0.0179 (2)	0.71894 (12)	0.0426 (3)
H1	0.883 (2)	0.553 (2)	0.5283 (14)	0.061 (5)*
H2	0.5631	0.5065	0.6250	0.036*
H3	0.4322	0.2723	0.6744	0.036*
H4	0.7014	−0.1520	0.6243	0.035*
H5	0.8912	−0.0276	0.5650	0.035*
H6	0.2498	0.0436	0.6561	0.051*
H7	0.3691	0.0676	0.7829	0.051*
H8	0.2805	−0.1258	0.7429	0.051*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0433 (5)	0.0268 (5)	0.0603 (6)	0.0010 (4)	0.0340 (4)	0.0008 (4)
O2	0.0390 (5)	0.0213 (5)	0.0572 (6)	0.0027 (3)	0.0275 (4)	0.0031 (4)
O3	0.0355 (5)	0.0273 (5)	0.0502 (5)	−0.0032 (3)	0.0220 (4)	0.0026 (4)
C1	0.0305 (6)	0.0253 (7)	0.0319 (6)	0.0004 (5)	0.0137 (5)	−0.0014 (5)
C2	0.0318 (6)	0.0212 (7)	0.0315 (6)	0.0001 (4)	0.0114 (5)	0.0006 (4)
C3	0.0326 (6)	0.0240 (7)	0.0377 (7)	0.0054 (5)	0.0152 (5)	0.0000 (5)
C4	0.0285 (6)	0.0298 (7)	0.0362 (6)	0.0025 (5)	0.0162 (5)	0.0006 (5)
C5	0.0294 (6)	0.0268 (7)	0.0302 (6)	−0.0025 (5)	0.0107 (5)	0.0004 (5)
C6	0.0352 (6)	0.0193 (7)	0.0340 (6)	0.0010 (5)	0.0119 (5)	−0.0005 (4)
C7	0.0330 (6)	0.0225 (7)	0.0356 (6)	0.0043 (5)	0.0146 (5)	−0.0019 (5)
C8	0.0402 (7)	0.0386 (9)	0.0583 (9)	−0.0047 (6)	0.0289 (6)	0.0027 (6)

Geometric parameters (Å, º)

O2—C2	1.3520 (15)	C6—C7	1.3590 (19)
O3—C5	1.3668 (16)	C3—H2	0.950
O3—C8	1.4287 (19)	C4—H3	0.950
C1—C2	1.4504 (18)	C6—H4	0.950
C1—C7	1.4354 (18)	C7—H5	0.950
C2—C3	1.367 (2)	C8—H6	0.980
C3—C4	1.4049 (19)	C8—H7	0.980
C4—C5	1.3643 (18)	C8—H8	0.980
C5—C6	1.4176 (19)	O2—H1	0.92 (2)
O1···O1^i	3.2319 (13)	C8···H3^xii	3.271
O1···O2	2.6049 (14)	C8···H5^vii	3.466
O1···O2^i	2.7100 (15)	C8···H7^xii	3.451
O1···C1	1.2558 (18)	C8···H8^xi	3.080
O1···C2	2.3159 (17)	H1···O1	2.074 (18)
O1···C7	2.3345 (17)	H1···O1^i	1.956 (19)
O1···C7^ii	3.5397 (17)	H1···O2^i	3.31 (2)
O1···C8^iii	3.4915 (17)	H1···O3^iii	3.537 (17)
O2···O1	2.6049 (14)	H1···C1	2.300 (18)
O2···O1^i	2.7100 (15)	H1···C1^i	3.15 (2)
O2···O3^iii	3.4471 (12)	H1···C2	1.861 (19)
O2···C3^iv	3.4257 (14)	H1···C3	3.07 (2)
O2···C4^iv	3.3809 (14)	H1···C8^iii	3.374 (15)
O2···C5^iii	3.4978 (14)	H1···H1^i	2.41 (2)
O2···C6^v	3.2668 (16)	H1···H2	3.266
O2···C7^v	3.5901 (15)	H1···H3^iv	3.318
O3···O2^vi	3.4471 (12)	H1···H4^v	3.061
O3···C1^vi	3.3890 (15)	H1···H5^v	3.075
O3···C1^vii	3.5667 (14)	H1···H7^iii	2.637
O3···C2^vi	3.2296 (13)	H1···H7^x	3.115
O3···C7^vii	3.4120 (14)	H1···H8^x	3.404
C1···O1	1.2558 (18)	H2···O2^iv	3.185
C1···O3^iii	3.3890 (15)	H2···O3^v	3.271
C1···O3^vii	3.5667 (14)	H2···C2^iv	3.109
C2···O1	2.3159 (17)	H2···C3^iv	3.011
C2···O3^iii	3.2296 (13)	H2···C5^iii	3.563
C2···C3^iv	3.5923 (15)	H2···C6^iii	3.232
C2···C5^iii	3.4766 (15)	H2···C7^iii	3.497
C3···O2^iv	3.4257 (14)	H2···H1	3.266
C3···C2^iv	3.5923 (15)	H2···H2^iv	2.948
C3···C3^iv	3.3527 (16)	H2···H4^v	2.743
C3···C5^iii	3.5704 (15)	H2···H4^iii	3.349
C3···C6^iii	3.2559 (16)	H3···O2^iv	3.112
C4···O2^iv	3.3809 (14)	H3···C8^xi	3.271
C4···C6^iii	3.5732 (16)	H3···H1^iv	3.318
C5···O2^vi	3.4978 (14)	H3···H4^iii	3.395
C5···C2^vi	3.4766 (15)	H3···H5^iii	3.440
C5···C3^vi	3.5704 (15)	H3···H6^xi	3.531
C5···C6^vii	3.3873 (15)	H3···H7^xi	3.481
C6···O2^viii	3.2668 (16)	H3···H8^xi	2.423
C6···C3^vi	3.2559 (16)	H4···O2^viii	2.437
C6···C4^vi	3.5732 (16)	H4···C2^viii	3.373
C6···C5^vii	3.3873 (15)	H4···C2^vi	3.578
C7···O1	2.3345 (17)	H4···C3^viii	3.418
C7···O1^ii	3.5397 (17)	H4···C3^vi	3.126
C7···O2^viii	3.5901 (15)	H4···C4^vi	3.146
C7···O3^vii	3.4120 (14)	H4···C4^vii	3.419
C7···C8^vii	3.5298 (19)	H4···C5^vi	3.591
C8···O1^vi	3.4915 (17)	H4···C5^vii	3.525
C8···C7^vii	3.5298 (19)	H4···H1^viii	3.061
O1···H1	2.074 (18)	H4···H2^viii	2.743
O1···H1^i	1.956 (19)	H4···H2^vi	3.349
O1···H5	2.466	H4···H3^vi	3.395
O1···H5^ii	2.613	H5···O1	2.466
O1···H6^ix	3.068	H5···O1^ii	2.613
O1···H6^vii	3.366	H5···O2^viii	3.070
O1···H7^iii	3.183	H5···C1^ii	3.416
O1···H7^x	2.974	H5···C7^ii	3.460
O1···H8^iii	3.160	H5···C8^vii	3.466
O1···H8^vii	3.476	H5···H1^viii	3.075
O2···H1^i	3.31 (2)	H5···H3^vi	3.440
O2···H2^iv	3.185	H5···H5^ii	2.793
O2···H3^iv	3.112	H5···H6^ix	2.948
O2···H4^v	2.437	H5···H6^vii	2.635
O2···H5^v	3.070	H5···H8^ix	3.447
O2···H7^iii	2.990	H6···O1^xiii	3.068
O3···H1^vi	3.537 (17)	H6···O1^vii	3.366
O3···H2^viii	3.271	H6···C1^xiii	3.586
C1···H1	2.300 (18)	H6···C1^vii	3.275
C1···H1^i	3.15 (2)	H6···C6^vii	3.543
C1···H5^ii	3.416	H6···C7^xiii	3.518
C1···H6^ix	3.586	H6···C7^vii	2.887
C1···H6^vii	3.275	H6···H3^xii	3.531
C1···H7^iii	3.518	H6···H5^xiii	2.948
C1···H8^iii	3.515	H6···H5^vii	2.635
C2···H1	1.861 (19)	H6···H8^xi	2.750
C2···H2^iv	3.109	H7···O1^vi	3.183
C2···H4^v	3.373	H7···O1^xiv	2.974
C2···H4^iii	3.578	H7···O2^vi	2.990
C2···H7^iii	3.446	H7···C1^vi	3.518
C3···H1	3.07 (2)	H7···C2^vi	3.446
C3···H2^iv	3.011	H7···C8^xi	3.451
C3···H4^v	3.418	H7···H1^vi	2.637
C3···H4^iii	3.126	H7···H1^xiv	3.115
C4···H4^iii	3.146	H7···H3^xii	3.481
C4···H4^vii	3.419	H7···H8^xi	2.534
C4···H8^xi	3.367	H8···O1^vi	3.160
C5···H2^vi	3.563	H8···O1^vii	3.476
C5···H4^iii	3.591	H8···C1^vi	3.515
C5···H4^vii	3.525	H8···C4^xii	3.367
C6···H2^vi	3.232	H8···C8^xii	3.080
C6···H6^vii	3.543	H8···H1^xiv	3.404
C7···H2^vi	3.497	H8···H3^xii	2.423
C7···H5^ii	3.460	H8···H5^xiii	3.447
C7···H6^ix	3.518	H8···H6^xii	2.750
C7···H6^vii	2.887	H8···H7^xii	2.534
C8···H1^vi	3.374 (15)
C5—O3—C8	118.14 (10)	C2—C3—H2	114.1
O1—C1—C2	117.51 (11)	C4—C3—H2	114.1
O1—C1—C7	120.19 (12)	C3—C4—H3	115.9
C2—C1—C7	122.31 (12)	C5—C4—H3	115.9
O2—C2—C1	115.03 (12)	C5—C6—H4	114.6
O2—C2—C3	115.89 (11)	C7—C6—H4	114.6
C1—C2—C3	129.07 (12)	C1—C7—H5	114.2
C2—C3—C4	131.75 (12)	C6—C7—H5	114.2
C3—C4—C5	128.24 (13)	O3—C8—H6	109.5
O3—C5—C4	122.98 (12)	O3—C8—H7	109.5
O3—C5—C6	110.79 (11)	O3—C8—H8	109.5
C4—C5—C6	126.23 (13)	H6—C8—H7	109.5
C5—C6—C7	130.73 (12)	H6—C8—H8	109.5
C1—C7—C6	131.64 (13)	H7—C8—H8	109.5
C2—O2—H1	108.5 (11)
C8—O3—C5—C4	−1.09 (16)	O2—C2—C3—C4	178.98 (11)
C8—O3—C5—C6	179.22 (9)	C1—C2—C3—C4	−0.7 (2)
O1—C1—C2—O2	−0.45 (15)	C2—C3—C4—C5	0.8 (2)
O1—C1—C2—C3	179.24 (11)	C3—C4—C5—O3	−179.26 (11)
O1—C1—C7—C6	−178.20 (12)	C3—C4—C5—C6	0.4 (2)
C2—C1—C7—C6	1.9 (2)	O3—C5—C6—C7	179.18 (11)
C7—C1—C2—O2	179.48 (10)	C4—C5—C6—C7	−0.5 (2)
C7—C1—C2—C3	−0.84 (18)	C5—C6—C7—C1	−1.0 (2)

Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) −x+2, −y, −z+1; (iii) −x+3/2, y+1/2, −z+3/2; (iv) −x+1, −y+1, −z+1; (v) x, y+1, z; (vi) −x+3/2, y−1/2, −z+3/2; (vii) −x+1, −y, −z+1; (viii) x, y−1, z; (ix) x+1, y, z; (x) x+1/2, −y+1/2, z−1/2; (xi) −x+1/2, y+1/2, −z+3/2; (xii) −x+1/2, y−1/2, −z+3/2; (xiii) x−1, y, z; (xiv) x−1/2, −y+1/2, z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H1···O1	0.92 (2)	2.074 (18)	2.605 (1)	115 (1)
O2—H1···O1^i	0.92 (2)	1.956 (19)	2.710 (2)	138 (2)
C6—H4···O2^viii	0.95	2.44	3.267 (2)	146
C7—H5···O1^ii	0.95	2.61	3.540 (2)	165
C8—H6···C7^vii	0.98	2.89	3.530 (2)	124

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