Bis(1-methyl-1-phenyl­ethyl) peroxide

Su, W.-Y.; Hou, G.-Y.; Yin, Q.-X.; Zhou, L.-N.

doi:10.1107/S1600536808033412

organic compounds

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ISSN: 2056-9890

Volume 64| Part 11| November 2008| Page o2128

doi:10.1107/S1600536808033412

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Bis(1-methyl-1-phenylethyl) peroxide

Wei-Yi Su,^a Guang-Yang Hou,^a Qiu-Xiang Yin ^a ^* and Li-Na Zhou ^a

^aSchool of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People's Republic of China
^*Correspondence e-mail: suweiyi222@yahoo.com.cn

(Received 23 September 2008; accepted 14 October 2008; online 18 October 2008)

In the crystal structure, the title compound (also called dicumyl peroxide), C₁₈H₂₂O₂, lies on a center of symmetry. The COOC plane including the dioxy group makes a dihedral angle of 79.10 (5)° with the phenyl ring. An intermolecular C—H⋯π interaction is observed between the phenyl groups.

Related literature

For general background, see: Ferrero (2006 ); Konar et al. (1993 ); Ramar & Alagar (2004 ); Wang et al. (1998 ).

Experimental

Crystal data

C₁₈H₂₂O₂
M_r = 270.36
Orthorhombic, P b c a
a = 10.040 (2) Å
b = 7.4774 (15) Å
c = 21.016 (4) Å
V = 1577.7 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 293 (2) K
0.25 × 0.20 × 0.15 mm

Data collection

Rigaku R-AXIS RAPID IP area-detector diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ) T_min = 0.982, T_max = 0.989
11957 measured reflections
1464 independent reflections
1232 reflections with I > 2σ(I)
R_int = 0.077

Refinement

R[F² > 2σ(F²)] = 0.043
wR(F²) = 0.110
S = 1.05
1464 reflections
92 parameters
H-atom parameters constrained
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

Cg is the centroid of the phenyl ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3A⋯Cgⁱ	0.93	2.93	3.7874 (17)	154
Symmetry code: (i) $[-x+1, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Data collection: RAPID-AUTO (Rigaku/MSC, 2004 ); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808033412/is2340sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808033412/is2340Isup2.hkl

checkCIF report

Comment top

The title compound, (I), a simple organic peroxide, has gradually become almost the most important additive in operations affected by molecular transport, such as grafting (Konar et al., 1993; Ramar & Alagar, 2004) and cross-linking (Wang et al., 1998; Ferrero, 2006), which are based on the formation of oxyradicals due to the thermal decomposition of the peroxides. It's widely used in the art as vulcanizing agents for resins and elastomers, as cross-linking agents for polyolefins.

The centrosymmetric molecular structure of (I) is shown in Fig. 1. In the molecule, two phenyl rings are, of course, parallel to each other due to the symmetry element. The peroxy unit has an O—O bond length of 1.6853 (16) Å, and the four atoms, C7, O1, O1A and C7A are coplanar with a C7—O1—O1A bond angle of 106.02 (9)°. There is no hydrogen bond in the packing structure, and cohesion of the crystal can be attributed to van der Waals interactions.

Related literature top

For general background, see: Ferrero (2006); Konar et al. (1993); Ramar & Alagar (2004); Wang et al. (1998).

Experimental top

At room temperature, the title compound (1 g) provided by Gaoqiao petrochemical corporation was dissolved in 20 mL ethanol (99.7%). The solvent was vaporized slowly by use of a film covering the container (beaker). Then the solution was placed in darkness until crystals appeared. The product was taken out from the solvent by tweezers, and dried in the air at room temperature.

Computing details top

Data collection: RAPID-AUTO (Rigaku/MSC, 2004); cell refinement: RAPID-AUTO (Rigaku/MSC, 2004); data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of the title compound, showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. The packing diagram of (I), viewed down the b axis. H atoms have been omitted.

Bis(1-methyl-1-phenylethyl) peroxide top

Crystal data top

C₁₈H₂₂O₂	D_x = 1.138 Mg m⁻³
M_r = 270.36	Melting point: 315.15 K
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 8972 reflections
a = 10.040 (2) Å	θ = 3.5–27.6°
b = 7.4774 (15) Å	µ = 0.07 mm⁻¹
c = 21.016 (4) Å	T = 293 K
V = 1577.7 (5) Å³	Plate, colorless
Z = 4	0.25 × 0.20 × 0.15 mm
F(000) = 584

Data collection top

Rigaku R-AXIS RAPID IP area-detector diffractometer	1464 independent reflections
Radiation source: rotating anode	1232 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.077
oscillation scans	θ_max = 25.5°, θ_min = 3.5°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −12→10
T_min = 0.982, T_max = 0.989	k = −9→9
11957 measured reflections	l = −25→25

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.043	H-atom parameters constrained
wR(F²) = 0.110	w = 1/[σ²(F_o²) + (0.0556P)² + 0.2734P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max = 0.010
1464 reflections	Δρ_max = 0.26 e Å⁻³
92 parameters	Δρ_min = −0.18 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.027 (7)

Crystal data top

C₁₈H₂₂O₂	V = 1577.7 (5) Å³
M_r = 270.36	Z = 4
Orthorhombic, Pbca	Mo Kα radiation
a = 10.040 (2) Å	µ = 0.07 mm⁻¹
b = 7.4774 (15) Å	T = 293 K
c = 21.016 (4) Å	0.25 × 0.20 × 0.15 mm

Data collection top

Rigaku R-AXIS RAPID IP area-detector diffractometer	1464 independent reflections
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	1232 reflections with I > 2σ(I)
T_min = 0.982, T_max = 0.989	R_int = 0.077
11957 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.043	0 restraints
wR(F²) = 0.110	H-atom parameters constrained
S = 1.05	Δρ_max = 0.26 e Å⁻³
1464 reflections	Δρ_min = −0.18 e Å⁻³
92 parameters

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.46269 (8)	0.07789 (11)	0.51277 (4)	0.0309 (3)
C1	0.44577 (13)	−0.10967 (18)	0.62787 (6)	0.0373 (4)
H1A	0.3746	−0.1115	0.5996	0.045*
C2	0.44768 (16)	−0.2285 (2)	0.67854 (6)	0.0462 (4)
H2A	0.3785	−0.3099	0.6836	0.055*
C3	0.55144 (16)	−0.2265 (2)	0.72135 (6)	0.0482 (4)
H3A	0.5527	−0.3060	0.7554	0.058*
C4	0.65322 (16)	−0.1055 (2)	0.71319 (6)	0.0453 (4)
H4A	0.7231	−0.1025	0.7422	0.054*
C5	0.65252 (13)	0.01215 (17)	0.66204 (6)	0.0353 (3)
H5A	0.7227	0.0920	0.6568	0.042*
C6	0.54838 (12)	0.01186 (16)	0.61873 (5)	0.0285 (3)
C7	0.54171 (12)	0.14706 (16)	0.56434 (6)	0.0302 (3)
C8	0.67730 (14)	0.20577 (19)	0.54013 (6)	0.0419 (4)
H8A	0.7274	0.1027	0.5271	0.063*
H8B	0.7242	0.2670	0.5734	0.063*
H8C	0.6660	0.2847	0.5045	0.063*
C9	0.45933 (16)	0.30860 (19)	0.58538 (6)	0.0457 (4)
H9A	0.3740	0.2689	0.6004	0.068*
H9B	0.4472	0.3880	0.5500	0.068*
H9C	0.5051	0.3703	0.6190	0.068*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0353 (5)	0.0293 (5)	0.0282 (5)	0.0064 (4)	−0.0042 (4)	−0.0065 (3)
C1	0.0372 (7)	0.0434 (8)	0.0312 (7)	−0.0045 (6)	0.0036 (6)	0.0002 (6)
C2	0.0558 (9)	0.0452 (9)	0.0377 (8)	−0.0046 (7)	0.0142 (7)	0.0028 (6)
C3	0.0711 (11)	0.0426 (9)	0.0309 (7)	0.0163 (7)	0.0120 (7)	0.0058 (6)
C4	0.0556 (9)	0.0506 (9)	0.0297 (7)	0.0182 (7)	−0.0080 (7)	−0.0051 (6)
C5	0.0383 (7)	0.0358 (7)	0.0319 (7)	0.0045 (6)	−0.0042 (6)	−0.0074 (5)
C6	0.0330 (7)	0.0288 (7)	0.0235 (6)	0.0042 (5)	0.0017 (5)	−0.0057 (5)
C7	0.0377 (7)	0.0271 (6)	0.0258 (6)	−0.0014 (5)	−0.0039 (5)	−0.0034 (5)
C8	0.0495 (8)	0.0387 (8)	0.0376 (7)	−0.0153 (6)	−0.0015 (7)	0.0017 (6)
C9	0.0654 (10)	0.0339 (8)	0.0377 (8)	0.0124 (7)	−0.0072 (7)	−0.0068 (6)

Geometric parameters (Å, º) top

O1—C7	1.4392 (15)	C5—C6	1.3862 (17)
O1—O1ⁱ	1.4853 (16)	C5—H5A	0.9300
C1—C6	1.3871 (18)	C6—C7	1.5273 (17)
C1—C2	1.387 (2)	C7—C8	1.5181 (18)
C1—H1A	0.9300	C7—C9	1.5292 (18)
C2—C3	1.377 (2)	C8—H8A	0.9600
C2—H2A	0.9300	C8—H8B	0.9600
C3—C4	1.375 (2)	C8—H8C	0.9600
C3—H3A	0.9300	C9—H9A	0.9600
C4—C5	1.3893 (19)	C9—H9B	0.9600
C4—H4A	0.9300	C9—H9C	0.9600

C7—O1—O1ⁱ	106.02 (9)	O1—C7—C8	110.23 (10)
C6—C1—C2	121.05 (13)	O1—C7—C6	110.47 (10)
C6—C1—H1A	119.5	C8—C7—C6	113.76 (10)
C2—C1—H1A	119.5	O1—C7—C9	101.74 (10)
C3—C2—C1	120.35 (14)	C8—C7—C9	110.70 (11)
C3—C2—H2A	119.8	C6—C7—C9	109.28 (10)
C1—C2—H2A	119.8	C7—C8—H8A	109.5
C4—C3—C2	119.21 (14)	C7—C8—H8B	109.5
C4—C3—H3A	120.4	H8A—C8—H8B	109.5
C2—C3—H3A	120.4	C7—C8—H8C	109.5
C3—C4—C5	120.61 (13)	H8A—C8—H8C	109.5
C3—C4—H4A	119.7	H8B—C8—H8C	109.5
C5—C4—H4A	119.7	C7—C9—H9A	109.5
C6—C5—C4	120.72 (13)	C7—C9—H9B	109.5
C6—C5—H5A	119.6	H9A—C9—H9B	109.5
C4—C5—H5A	119.6	C7—C9—H9C	109.5
C5—C6—C1	118.05 (12)	H9A—C9—H9C	109.5
C5—C6—C7	121.56 (11)	H9B—C9—H9C	109.5
C1—C6—C7	120.31 (11)

C6—C1—C2—C3	0.7 (2)	O1ⁱ—O1—C7—C6	−65.93 (12)
C1—C2—C3—C4	−0.1 (2)	O1ⁱ—O1—C7—C9	178.12 (10)
C2—C3—C4—C5	−0.7 (2)	C5—C6—C7—O1	155.72 (11)
C3—C4—C5—C6	0.95 (19)	C1—C6—C7—O1	−27.54 (15)
C4—C5—C6—C1	−0.32 (18)	C5—C6—C7—C8	31.13 (16)
C4—C5—C6—C7	176.48 (11)	C1—C6—C7—C8	−152.13 (12)
C2—C1—C6—C5	−0.51 (19)	C5—C6—C7—C9	−93.14 (14)
C2—C1—C6—C7	−177.36 (12)	C1—C6—C7—C9	83.59 (14)
O1ⁱ—O1—C7—C8	60.64 (13)

Symmetry code: (i) −x+1, −y, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···Cgⁱⁱ	0.93	2.93	3.7874 (17)	154

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

Experimental details

Crystal data
Chemical formula	C₁₈H₂₂O₂
M_r	270.36
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	293
a, b, c (Å)	10.040 (2), 7.4774 (15), 21.016 (4)
V (Å³)	1577.7 (5)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.25 × 0.20 × 0.15

Data collection
Diffractometer	Rigaku R-AXIS RAPID IP area-detector diffractometer
Absorption correction	Multi-scan (ABSCOR; Higashi, 1995)
T_min, T_max	0.982, 0.989
No. of measured, independent and observed [I > 2σ(I)] reflections	11957, 1464, 1232
R_int	0.077
(sin θ/λ)_max (Å⁻¹)	0.606

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.043, 0.110, 1.05
No. of reflections	1464
No. of parameters	92
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.26, −0.18

Computer programs: RAPID-AUTO (Rigaku/MSC, 2004), CrystalStructure (Rigaku/MSC, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···Cgⁱ	0.93	2.93	3.7874 (17)	154

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

Acknowledgements

The authors gratefully acknowledge financial support from the SRCICT of Tianjin University and the material DCP afforded by Gaoqiao Petrochemical Corporation.

References

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