Iodo­durene

The title compound (systematic name: 1-iodo-2,3,5,6-tetra­methyl­benzene), C₁₀H₁₃I, crystallizes in the chiral space group P2₁2₁2₁. The I atom is displaced by 0.1003 (5) Å from the mean plane of the ten C atoms [maximum deviation = 0.018 (6) Å]. In the crystal, there are no significant inter­molecular inter­actions present.

Related literature

For the crystal structure of bromo­durene, see: Charbonneau et al. (1964, 1965). For the physical properties of mono-halogen­ated derivatives of durene, see: Balcou et al. (1965). For standard bond lengths in similar compounds, see: Allen (2002); Hope et al. (1970).

Experimental

Crystal data

• C₁₀H₁₃I

• M_r = 260.11

• Orthorhombic, P 2₁ 2₁ 2₁

• a = 5.5099 (3) Å

• b = 11.8839 (5) Å

• c = 15.1704 (6) Å

• V = 993.34 (8) ų

• Z = 4

• Mo Kα radiation

• μ = 3.16 mm⁻¹

• T = 293 K

• 0.10 × 0.05 × 0.04 mm

Data collection

• Nonius KappaCCD diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996) T_min = 0.140, T_max = 0.193

• 26027 measured reflections

• 2271 independent reflections

• 2036 reflections with I > 3σ(I)

• R_int = 0.047

Refinement

• R[F² > 2σ(F²)] = 0.035

• wR(F²) = 0.039

• S = 1.04

• 3272 reflections

• 101 parameters

• 36 restraints

• H-atom parameters constrained

• Δρ_max = 0.84 e Å⁻³

• Δρ_min = −0.71 e Å⁻³

• Absolute structure: Flack (1983), 925 Friedal pairs

• Flack parameter: −0.03 (4)

Data collection: COLLECT (Nonius, 2001); cell refinement: DIRAX/LSQ (Duisenberg et al., 2003); data reduction: EVALCCD (Duisenberg et al., 2003); program(s) used to solve structure: SIR2002 (Burla et al., 2005); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: CAMERON (Watkin et al., 1996) and DIAMOND (Brandenburg, 2012); software used to prepare material for publication: CRYSTALS.

Supporting information

S1. Comment

Substituted benzene compounds are generally liquid at room temperature so relatively few crystal structure analyses of such compounds have been reported. We have synthesized three mono-halogenated products of duren; chloro-, bromo- and iododurene. These derivatives are solid at 293 K and their dielectric behavior depends on the nature of the substituent, and in particular of its mass and volume. Contrary to chlorodurene the title iododurene in the solid phase has a quite low permeability equal to only 2.6, which changes abruptly at fusion to a value of ca. 4 (Balcou et al., 1965). We report herein on its crystal structure.

The molecular structure of the title compound is illustrated in Fig. 1. The molecule is almost planar with the I atom displaced from the mean plane of the nine C atoms [maximum deviation 0.018 (6) Å for the methyl C atoms C7 and C9] by 0.1003 (5) Å. The average endocyclic angles facing the I atom and the methyl groups are 124.98 (10)° and 117.41 (10)°, respectively. The structural study did not reveal any disorder and the average intramolecular bond lengths, [C_ar-I = 2.139 (3) Å, C_ar-C_ar = 1.400 (5) Å and C_ar-C_Me = 1.498 (6) Å], as well as the average single C_ar-H bond length [0.940 Å], agree with the distances reported in the literature [Cambridge Structural Database (Allen, 2002); Hope et al., 1970].

In the crystal, the a axis is very short, so the molecules stack along this direction (Fig. 2). The best mean plane passing through the carbon and iodine atoms, calculated with the program Molax of CRYSTALS (Betteridge et al., 2003), indicated that the angle between the normal to this mean plane is ca. 50.1° relative to the a axis, ca. 44.8° relative to the b axis and ca. 74.5° relative to the c axis (Fig. 3).

The crystals obtained sublimate a little at ambient temperature. Moreover, at room temperature iododurene and the isotypic product bromodurene (Charbonneau et al., 1964, 1965) crystallize in the same orthorhombic space group with fixed orientations of the dipolar grouping not presenting dielectric dispersion. This fact could be interpreted by the importance of the distribution of the masses of the substituents, that inhibit the possibility of molecular reorientation like in chlorodurene (Balcou et al., 1965).

Related literature

For the crystal structure of bromodurene, see: Charbonneau et al. (1964, 1965). For the physical properties of mono-halogenated derivatives of durene, see: Balcou et al. (1965). For standard bond lengths in similar compounds, see: Allen (2002); Hope et al. (1970).

S2. Experimental

The title compound was synthesized by direct iodination of durene. Equimolecular quantities of iodine and durene were dissolved in pure acetic acid at 343 K. Progressive iodination was obtained by oxidation of durene using drops of pure sulfuric and nitric acids diluted in acetic acid. Total precipitation of iododurene was obtained by dilution with water. Purification was done by chromatography on a silica column and finally precipitation of a solution in chloroform, giving colouress needle-like crystals.

S3. Refinement

All H atoms were localized in a difference Fourier map. The C-bound H atoms were included in calculated positions and treated as riding atoms: C-H = 0.94 Å for CH H atoms, and 0.95 - 0.97 Å for CH₃ H atoms, with U_iso(H) = k × U_eq(C) where k = 1.5 for CH₃ H atoms and = 1.2 for other H atoms.

Computing details

Data collection: COLLECT (Nonius, 2001); cell refinement: DIRAX/LSQ (Duisenberg et al., 2003); data reduction: EVALCCD (Duisenberg et al., 2003); program(s) used to solve structure: SIR2002 (Burla et al., 2005); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: CAMERON (Watkin et al., 1996) and DIAMOND (Brandenburg, 2012); software used to prepare material for publication: CRYSTALS (Betteridge et al., 2003).

Figures

	Fig. 1. The molecular structure of the title molecule, with atom numbering. The displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A view along the a axis of the crystal packing of the title compound.
	Fig. 3. A view along the c axis of the crystal packing of the title compound.

1-Iodo-2,3,5,6-tetramethylbenzene

Crystal data

C10H13I	Dx = 1.739 Mg m^−3
Mr = 260.11	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 8232 reflections
a = 5.5099 (3) Å	θ = 3.7–27.5°
b = 11.8839 (5) Å	µ = 3.16 mm^−1
c = 15.1704 (6) Å	T = 293 K
V = 993.34 (8) Å^3	Needle, colourless
Z = 4	0.10 × 0.05 × 0.04 mm
F(000) = 503.986

Data collection

Nonius KappaCCD diffractometer	2036 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.047
CCD scans	θmax = 27.5°, θmin = 3.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −7→7
Tmin = 0.140, Tmax = 0.193	k = −15→15
26027 measured reflections	l = −19→19
2271 independent reflections

Refinement

Refinement on F	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.035	H-atom parameters constrained
wR(F^2) = 0.039	W = [weight]*[1-(deltaF/6*sigmaF)^2]^2
S = 1.04	(Δ/σ)max < 0.001
3272 reflections	Δρmax = 0.84 e Å^−3
101 parameters	Δρmin = −0.71 e Å^−3
36 restraints	Absolute structure: Flack (1983), 925 Friedal pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.03 (4)

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles

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
I1	0.93848 (10)	0.80448 (4)	0.27027 (3)	0.0686 (2)
C1	0.9383 (7)	0.9098 (3)	0.1559 (2)	0.0429 (11)
C2	0.7711 (8)	0.9981 (4)	0.1533 (3)	0.0473 (16)
C3	0.7637 (8)	1.0638 (3)	0.0755 (3)	0.0483 (16)
C4	0.9270 (10)	1.0376 (4)	0.0091 (3)	0.0507 (16)
C5	1.0976 (8)	0.9513 (4)	0.0123 (2)	0.0460 (14)
C6	1.1033 (7)	0.8838 (3)	0.0887 (3)	0.0423 (14)
C7	0.5997 (12)	1.0208 (5)	0.2295 (4)	0.071 (2)
C8	0.5866 (12)	1.1574 (5)	0.0651 (4)	0.067 (2)
C9	1.2673 (11)	0.9310 (5)	−0.0622 (4)	0.064 (2)
C10	1.2821 (11)	0.7894 (5)	0.0980 (3)	0.0597 (19)
H41	0.92110	1.08070	−0.04290	0.0610*
H71	0.69240	1.03120	0.28260	0.1071*
H72	0.50940	1.08740	0.21780	0.1072*
H73	0.49160	0.95840	0.23690	0.1071*
H81	0.62710	1.21740	0.10510	0.1008*
H82	0.59650	1.18410	0.00600	0.1008*
H83	0.42310	1.13100	0.07630	0.1010*
H91	1.24630	0.98940	−0.10560	0.0971*
H92	1.43080	0.93360	−0.04010	0.0970*
H93	1.23570	0.85840	−0.08810	0.0971*
H101	1.38670	0.80080	0.14830	0.0892*
H102	1.38000	0.78630	0.04650	0.0892*
H103	1.19650	0.71900	0.10410	0.0891*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I1	0.0831 (3)	0.0727 (3)	0.0500 (2)	−0.0082 (2)	−0.0036 (2)	0.0120 (2)
C1	0.046 (2)	0.044 (2)	0.0387 (19)	−0.006 (2)	−0.004 (2)	0.0006 (17)
C2	0.047 (3)	0.044 (2)	0.051 (3)	−0.005 (2)	0.000 (2)	−0.009 (2)
C3	0.046 (3)	0.040 (2)	0.059 (3)	−0.004 (2)	−0.011 (2)	−0.007 (2)
C4	0.055 (3)	0.045 (2)	0.052 (3)	−0.007 (3)	−0.011 (3)	0.0031 (19)
C5	0.047 (3)	0.048 (2)	0.043 (2)	−0.010 (2)	−0.001 (2)	−0.0036 (18)
C6	0.041 (3)	0.041 (2)	0.045 (2)	−0.0034 (18)	−0.0062 (18)	−0.0043 (17)
C7	0.070 (4)	0.071 (3)	0.072 (4)	0.000 (3)	0.013 (4)	−0.021 (3)
C8	0.063 (4)	0.052 (3)	0.087 (4)	0.008 (3)	−0.019 (4)	−0.005 (3)
C9	0.060 (4)	0.077 (4)	0.056 (3)	−0.009 (3)	0.005 (3)	−0.011 (3)
C10	0.056 (3)	0.053 (3)	0.070 (4)	0.011 (3)	−0.006 (3)	−0.008 (3)

Geometric parameters (Å, º)

I1—C1	2.139 (3)	C7—H71	0.9600
C1—C2	1.397 (6)	C7—H72	0.9500
C1—C6	1.401 (5)	C7—H73	0.9600
C2—C3	1.416 (6)	C8—H81	0.9600
C2—C7	1.517 (8)	C8—H82	0.9500
C3—C4	1.386 (7)	C8—H83	0.9700
C3—C8	1.488 (7)	C9—H91	0.9600
C4—C5	1.392 (7)	C9—H92	0.9600
C5—C6	1.410 (6)	C9—H93	0.9600
C5—C9	1.487 (7)	C10—H101	0.9700
C6—C10	1.500 (7)	C10—H102	0.9500
C4—H41	0.9400	C10—H103	0.9600
I1—C1—C2	117.6 (3)	H71—C7—H72	109.00
I1—C1—C6	117.5 (3)	H71—C7—H73	109.00
C2—C1—C6	125.0 (3)	H72—C7—H73	110.00
C1—C2—C3	117.2 (4)	C3—C8—H81	110.00
C1—C2—C7	121.5 (4)	C3—C8—H82	108.00
C3—C2—C7	121.3 (4)	C3—C8—H83	110.00
C2—C3—C4	117.6 (4)	H81—C8—H82	109.00
C2—C3—C8	121.3 (4)	H81—C8—H83	110.00
C4—C3—C8	121.1 (4)	H82—C8—H83	109.00
C3—C4—C5	125.4 (4)	C5—C9—H91	109.00
C4—C5—C6	117.6 (4)	C5—C9—H92	109.00
C4—C5—C9	121.2 (4)	C5—C9—H93	110.00
C6—C5—C9	121.2 (4)	H91—C9—H92	109.00
C1—C6—C5	117.3 (3)	H91—C9—H93	110.00
C1—C6—C10	121.5 (4)	H92—C9—H93	110.00
C5—C6—C10	121.2 (4)	C6—C10—H101	111.00
C3—C4—H41	118.00	C6—C10—H102	109.00
C5—C4—H41	117.00	C6—C10—H103	110.00
C2—C7—H71	109.00	H101—C10—H102	108.00
C2—C7—H72	109.00	H101—C10—H103	110.00
C2—C7—H73	110.00	H102—C10—H103	109.00
I1—C1—C2—C3	−176.8 (3)	C7—C2—C3—C4	179.9 (5)
I1—C1—C2—C7	1.5 (6)	C7—C2—C3—C8	−0.3 (7)
C6—C1—C2—C3	2.1 (6)	C2—C3—C4—C5	0.4 (7)
C6—C1—C2—C7	−179.6 (4)	C8—C3—C4—C5	−179.4 (5)
I1—C1—C6—C5	178.1 (3)	C3—C4—C5—C6	0.9 (7)
I1—C1—C6—C10	−3.0 (5)	C3—C4—C5—C9	−179.2 (5)
C2—C1—C6—C5	−0.8 (6)	C4—C5—C6—C1	−0.7 (6)
C2—C1—C6—C10	178.1 (4)	C4—C5—C6—C10	−179.6 (4)
C1—C2—C3—C4	−1.8 (6)	C9—C5—C6—C1	179.4 (4)
C1—C2—C3—C8	178.0 (4)	C9—C5—C6—C10	0.4 (7)