5-Iodo­tropolone

The structure of the title compound, 5-iodo­tropolone (systematic name: 2-hydr­oxy-5-iodo­cyclo­hepta-2,4,6-trien-1-one), C₇H₅IO₂, features both intra- and inter­molecular O—H...O hydrogen bonds. The hydrogen bonds, as well as I...I inter­actions, link the mol­ecules into layers parallel to the b axis and one of the ac-plane diagonals of the crystal structure.

Key indicators

• Single-crystal X-ray study
• T = 153 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.019
• wR factor = 0.053
• Data-to-parameter ratio = 16.0

checkCIF/PLATON results

No syntax errors found



Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           27.50
           From the CIF: _reflns_number_total               1598
           Count of symmetry unique reflns          914
           Completeness (_total/calc)            174.84%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       684
           Fraction of Friedel pairs measured     0.748
           Are heavy atom types Z>Si present        yes

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   0 ALERT level C = Check and explain
   1 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
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

---

Computing details

Data collection: CrystalClear (Rigaku, 1999); cell refinement: CrystalClear; data reduction: CrystalStructure (Rigaku/MSC, 2006); program(s) used to solve structure: SIR2002 (Burla et al., 2002); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: ORTEPIII (Burnett & Johnson, 1996) and Mercury (Version 1.3; Bruno et al., 2002); software used to prepare material for publication: CrystalStructure.

2-Hydroxy-5-iodocyclohepta-2,4,6-trien-1-one

Crystal data

C7H5IO2	F(000) = 232.00
Mr = 248.02	Dx = 2.291 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71070 Å
Hall symbol: P 2yb	Cell parameters from 1183 reflections
a = 4.1091 (16) Å	θ = 3.7–27.5°
b = 6.000 (2) Å	µ = 4.38 mm^−1
c = 14.603 (5) Å	T = 153 K
β = 93.1935 (19)°	Prism, yellow
V = 359.5 (2) Å^3	0.15 × 0.12 × 0.04 mm
Z = 2

Data collection

Rigaku Saturn diffractometer	1521 reflections with I > 2σ(I)
Detector resolution: 7.31 pixels mm^-1	Rint = 0.023
ω scans	θmax = 27.5°
Absorption correction: multi-scan (Jacobson, 1998)	h = −5→5
Tmin = 0.545, Tmax = 0.839	k = −7→7
2766 measured reflections	l = −18→15
1598 independent reflections

Refinement

Refinement on F^2	w = 1/[0.0002Fo^2 + σ(Fo^2)]/(4Fo^2)
R[F^2 > 2σ(F^2)] = 0.019	(Δ/σ)max < 0.001
wR(F^2) = 0.053	Δρmax = 1.06 e Å^−3
S = 1.01	Δρmin = −1.03 e Å^−3
1598 reflections	Absolute structure: Flack (1983), 692 Friedel pairs
100 parameters	Absolute structure parameter: 0.03 (3)
H atoms treated by a mixture of independent and constrained refinement

Special details

Geometry. ENTER SPECIAL DETAILS OF THE MOLECULAR GEOMETRY

Refinement. Refinement was performed using all reflections. The weighted R-factor (wR) and goodness of fit (S) are based on F². R-factor (gt) are based on 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
I1	0.90084 (4)	−0.05705 (14)	0.081250 (10)	0.02047 (5)
O1	0.6170 (8)	0.3840 (4)	0.47486 (19)	0.0256 (7)
O2	0.3453 (8)	0.6720 (4)	0.3635 (2)	0.0263 (7)
C1	0.6459 (10)	0.3411 (6)	0.3918 (3)	0.0203 (9)
C2	0.4933 (9)	0.4993 (5)	0.3265 (2)	0.0182 (9)
C3	0.4797 (9)	0.4929 (5)	0.2319 (2)	0.0182 (9)
C4	0.6020 (9)	0.3336 (6)	0.1715 (2)	0.0206 (9)
C5	0.7680 (9)	0.1420 (6)	0.1919 (2)	0.0178 (8)
C6	0.8693 (10)	0.0588 (6)	0.2808 (2)	0.0219 (10)
C7	0.8142 (10)	0.1445 (6)	0.3652 (2)	0.0200 (9)
H1	0.379 (13)	0.686 (8)	0.423 (3)	0.024 (12)*
H2	0.3718	0.6159	0.2027	0.022*
H3	0.5618	0.3636	0.1080	0.024*
H4	0.9907	−0.0760	0.2810	0.026*
H5	0.9043	0.0588	0.4151	0.024*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I1	0.01764 (11)	0.02625 (12)	0.01767 (11)	0.00265 (18)	0.00236 (7)	−0.00156 (18)
O1	0.0418 (17)	0.0221 (16)	0.0126 (12)	0.0013 (10)	−0.0015 (11)	0.0019 (9)
O2	0.0396 (17)	0.0216 (14)	0.0171 (13)	0.0091 (12)	−0.0023 (11)	−0.0030 (11)
C1	0.0213 (18)	0.0200 (17)	0.0190 (18)	−0.0039 (15)	−0.0038 (14)	0.0015 (15)
C2	0.0227 (17)	0.013 (2)	0.0180 (17)	0.0001 (11)	−0.0033 (13)	0.0016 (11)
C3	0.0201 (16)	0.018 (2)	0.0161 (15)	0.0058 (11)	−0.0043 (12)	0.0022 (11)
C4	0.0202 (18)	0.0245 (19)	0.0169 (18)	−0.0000 (14)	−0.0012 (14)	−0.0000 (14)
C5	0.0156 (16)	0.0200 (17)	0.0176 (16)	−0.0014 (13)	0.0002 (13)	0.0003 (14)
C6	0.024 (2)	0.025 (2)	0.0174 (19)	0.0064 (15)	0.0006 (15)	0.0045 (14)
C7	0.0231 (19)	0.0190 (17)	0.0178 (16)	0.0047 (14)	−0.0007 (14)	0.0057 (14)

Geometric parameters (Å, º)

I1—C5	2.105 (3)	C5—C6	1.431 (5)
O1—C1	1.252 (5)	C6—C7	1.367 (5)
O2—C2	1.332 (4)	O2—H1	0.87 (5)
C1—C2	1.462 (5)	C3—H2	0.950
C1—C7	1.432 (5)	C4—H3	0.950
C2—C3	1.380 (5)	C6—H4	0.950
C3—C4	1.412 (5)	C7—H5	0.950
C4—C5	1.361 (5)
O1···O1^i	3.247 (3)	C6···H2^viii	3.504
O1···O1^ii	3.247 (3)	C6···H2^ix	3.590
O1···O2^i	2.678 (4)	C7···H1^viii	3.41 (5)
O1···C1^ii	3.566 (5)	C7···H1^i	3.25 (5)
O1···C7^ii	3.391 (5)	H1···O1^ii	1.91 (5)
O1···C7^iii	3.571 (4)	H1···C1^ii	2.87 (5)
O2···O1^ii	2.678 (4)	H1···C7^vi	3.41 (5)
O2···C1^iv	3.536 (5)	H1···C7^ii	3.25 (5)
O2···C6^v	3.226 (5)	H1···H4^v	2.916
O2···C6^vi	3.431 (5)	H1···H5^v	2.967
O2···C7^v	3.579 (5)	H1···H5^vi	3.115
O2···C7^vi	3.427 (4)	H1···H5^ii	2.802
C1···O1^i	3.566 (5)	H2···I1^v	3.218
C1···O2^vii	3.536 (5)	H2···I1^vi	3.486
C2···C7^iv	3.580 (5)	H2···C4^iv	3.595
C6···O2^viii	3.431 (5)	H2···C5^vi	3.559
C6···O2^ix	3.226 (5)	H2···C6^v	3.590
C7···O1^i	3.391 (5)	H2···C6^vi	3.504
C7···O1^x	3.571 (4)	H2···H4^v	2.717
C7···O2^viii	3.427 (4)	H2···H4^vi	3.297
C7···O2^ix	3.579 (5)	H3···I1^xii	3.300
C7···C2^vii	3.580 (5)	H4···O2^viii	3.336
I1···H2^viii	3.486	H4···O2^ix	2.380
I1···H2^ix	3.218	H4···C2^viii	3.356
I1···H3^xi	3.300	H4···C2^ix	3.324
O1···H1^i	1.91 (5)	H4···C3^viii	3.383
O1···H5^iv	3.586	H4···C3^ix	3.377
O1···H5^ii	2.942	H4···H1^ix	2.916
O1···H5^iii	2.683	H4···H2^viii	3.297
O2···H4^v	2.380	H4···H2^ix	2.717
O2···H4^vi	3.336	H5···O1^vii	3.586
O2···H5^v	3.064	H5···O1^i	2.942
O2···H5^vi	3.322	H5···O1^x	2.683
O2···H5^ii	3.511	H5···O2^viii	3.322
C1···H1^i	2.87 (5)	H5···O2^ix	3.064
C1···H5^iv	3.519	H5···O2^i	3.511
C1···H5^iii	3.534	H5···C1^vii	3.519
C2···H4^v	3.324	H5···C1^x	3.534
C2···H4^vi	3.356	H5···H1^viii	3.115
C3···H4^v	3.377	H5···H1^ix	2.967
C3···H4^vi	3.383	H5···H1^i	2.802
C4···H2^vii	3.595	I1···I1^xiii	3.9384 (9)
C5···H2^viii	3.559
O1—C1—C2	116.0 (3)	C5—C6—C7	129.3 (3)
O1—C1—C7	120.4 (3)	C1—C7—C6	131.4 (3)
C2—C1—C7	123.6 (3)	C2—O2—H1	115 (3)
O2—C2—C1	115.4 (3)	C2—C3—H2	114.8
O2—C2—C3	115.7 (3)	C4—C3—H2	114.8
C1—C2—C3	128.8 (3)	C3—C4—H3	115.7
C2—C3—C4	130.4 (3)	C5—C4—H3	115.5
C3—C4—C5	128.8 (3)	C5—C6—H4	115.3
I1—C5—C4	117.4 (2)	C7—C6—H4	115.5
I1—C5—C6	115.0 (2)	C1—C7—H5	114.3
C4—C5—C6	127.6 (3)	C6—C7—H5	114.3
O1—C1—C2—O2	0.8 (5)	C1—C2—C3—C4	1.0 (7)
O1—C1—C2—C3	−178.6 (3)	C2—C3—C4—C5	−0.0 (6)
O1—C1—C7—C6	177.8 (4)	C3—C4—C5—I1	178.6 (3)
C2—C1—C7—C6	−0.8 (7)	C3—C4—C5—C6	−2.3 (7)
C7—C1—C2—O2	179.5 (3)	I1—C5—C6—C7	−178.0 (3)
C7—C1—C2—C3	0.1 (5)	C4—C5—C6—C7	2.9 (7)
O2—C2—C3—C4	−178.3 (3)	C5—C6—C7—C1	−0.9 (7)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H1···O1	0.87 (5)	2.18 (5)	2.584 (4)	108 (4)
O2—H1···O1^ii	0.87 (5)	1.91 (5)	2.678 (4)	146 (4)

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