2-Bromo-2-propyl phenyl sulfone

Crystalline 2-bromo-2-propyl phenyl sulfone (α-bromo­iso­propyl phenyl sulfone), C₉H₁₁BrO₂S, exhibits no rotational disorder of its α-bromo­iso­propyl group, in contrast to the large disorder of the same group exhibited by crystalline 2-bromo-2-propyl mesityl sulfone.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.012 Å
• R factor = 0.034
• wR factor = 0.094
• Data-to-parameter ratio = 8.3

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

General Notes



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           25.03
         From the CIF: _reflns_number_total               1008
         Count of symmetry unique reflns         1007
         Completeness (_total/calc)            100.10%
         TEST3: Check Friedels for noncentro structure
         Estimate of Friedel pairs measured         1
         Fraction of Friedel pairs measured     0.001
         Are heavy atom types Z>Si present          yes
          WARNING: Large fraction of Friedel related reflns may
                   be needed to determine absolute structure

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S1. Comment

The unexpected large rotational disorder of the 2-bromo-2-propyl group that characterized crystalline 2-bromo-2-propyl mesityl sulfone (Chan-Yu-King et al., 2001) prompted us to examine its less hindered analog, 2-bromo-2-propyl phenyl sulfone, (I).

The X-ray structure of (I), shown in Fig. 1 with its atom numbering, shows it to be a single rotamer, completely devoid of rotational disorder. The Br atom of this rotamer resides on the side of the sulfonyl group adjacent to O1. There is little steric interaction in (I), the most prominent being C6···C9 and Br···C2 which are, respectively, 0.07 Å greater than and 0.01 Å less than the sum of their van der Waals radii. The shortest intermolecular distances are O1···C9, O2···C8, and Br···C3 which are, respectively, -0.09 Å less than, 0.19 Å greater than, and 0.01 Å greater than the sum of their van der Waals radii. The shortest intra- and intermolecular contact distances are given in Table 1. The intermolecular packing is shown by Fig. 2.

S2. Experimental

2-Bromo-2-propyl phenyl sulfone, (I), was prepared from phenyl 2-propyl sulfone (Matthews, 1972) by treatment with CBr₄–powdered KOH–tert-BuOH (Parady, 1977; see also, Meyers et al., 1977; Meyers, 1978), recrystallized from hexanes and used in this study (m.p. 367–368 K). Similar reactions with CBrCl₃, CCl₂Br₂ or CBr₂F₂ instead of CBr₄ produced varying yields of (I) (Parady, 1977).

S3. Refinement

The acentric polar space group of (I) was unexpected and caused difficulty with respect to the data/parameter ratio which resulted in higher than normal standard uncertainties. Also, since Friedel pairs were not collected, we were unable to use the results of the Flack parameter to determine whether or not the orientation of the crystal on the diffractometer and of the model were identical. However, a comparison of the wR(F²) values for the model and its inverse gave values of 0.094 and 0.097, respectively, indicating that the selected model is most likely correct. The rotational orientation of the methyl groups were refined by the circular Fourier method available in SHELXL97 (Sheldrick, 1997). All H atoms are riding.

Computing details

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation,1996); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: PROCESS in TEXSAN (Molecular Structure Corporation, 1997); program(s) used to solve structure: SIR92 (Burla et al., 1989); program(s) used to refine structure: LS in TEXSAN and SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP (Johnson, 1965) in TEXSAN; software used to prepare material for publication: TEXSAN, SHELXL97, and PLATON (Spek, 2000).

Figures

	Fig. 1. The molecular structure and atom numbering scheme for (I) with displacement ellipsoids at the 50% probablilty level.
	Fig. 2. The molecular packing in (I) as viewed down the c axis. Color code: green = Br, red = O, yellow = S.

α-bromoisopropyl phenyl sulfone

Crystal data

C9H11BrO2S	Dx = 1.657 Mg m^−3
Mr = 263.15	Melting point = 419–420 K
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71069 Å
a = 21.134 (2) Å	Cell parameters from 25 reflections
b = 6.2537 (11) Å	θ = 12.5–14.6°
c = 7.979 (2) Å	µ = 4.06 mm^−1
V = 1054.6 (4) Å^3	T = 296 K
Z = 4	Prism, colorless
F(000) = 528	0.36 × 0.20 × 0.15 mm

Data collection

Rigaku AFC-5S diffractometer	668 reflections with I > 2σ(I)
Radiation source: sealed tube	Rint = 0.043
Graphite monochromator	θmax = 25.0°, θmin = 1.9°
ω scans	h = 0→25
Absorption correction: ψ scan (North et al., 1968)	k = −7→7
Tmin = 0.398, Tmax = 0.544	l = 0→9
1917 measured reflections	3 standard reflections every 100 reflections
1008 independent reflections	intensity decay: 3.2%

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.034	w = 1/[σ^2(Fo^2) + (0.0492P)^2 + 0.1257P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.094	(Δ/σ)max < 0.001
S = 1.01	Δρmax = 0.31 e Å^−3
1008 reflections	Δρmin = −0.27 e Å^−3
121 parameters	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.0094 (15)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 0 Friedel opposites, wR(F^2) (inverse) 0.097
Secondary atom site location: difference Fourier map	Absolute structure parameter: 0.09 (2)

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

	x	y	z	Uiso*/Ueq
Br	0.34405 (4)	0.11425 (18)	0.95490 (9)	0.0798 (5)
S1	0.35712 (9)	0.1208 (3)	0.5784 (3)	0.0510 (5)
O1	0.3573 (3)	−0.1059 (8)	0.5880 (12)	0.086 (2)
O2	0.3329 (3)	0.2233 (11)	0.4315 (8)	0.0718 (17)
C1	0.4349 (3)	0.2101 (12)	0.6120 (9)	0.0451 (18)
C2	0.4779 (4)	0.0770 (15)	0.6900 (13)	0.065 (2)
C3	0.5415 (4)	0.1520 (19)	0.7061 (13)	0.081 (3)
C4	0.5577 (4)	0.3453 (18)	0.6416 (12)	0.073 (3)
C5	0.5150 (4)	0.4728 (16)	0.5649 (14)	0.076 (3)
C6	0.4542 (4)	0.4064 (12)	0.5477 (11)	0.057 (2)
C7	0.3092 (3)	0.2238 (13)	0.7476 (9)	0.0473 (19)
C8	0.2421 (3)	0.1324 (12)	0.7296 (10)	0.062 (3)
C9	0.3116 (4)	0.4693 (11)	0.7572 (12)	0.0539 (19)
H2	0.4659	−0.0564	0.7306	0.078*
H3	0.5717	0.0688	0.7605	0.097*
H4	0.5994	0.3913	0.6505	0.088*
H5	0.5272	0.6058	0.5239	0.091*
H6	0.4251	0.4929	0.4924	0.068*
H8a	0.2158	0.1871	0.8178	0.092*
H8b	0.2436	−0.0207	0.7365	0.092*
H8c	0.2248	0.1739	0.6231	0.092*
H9a	0.2808	0.5188	0.8366	0.081*
H9b	0.3025	0.5284	0.6489	0.081*
H9c	0.3530	0.5137	0.7923	0.081*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br	0.0675 (5)	0.1134 (10)	0.0587 (6)	−0.0113 (6)	−0.0062 (6)	0.0336 (6)
S1	0.0518 (11)	0.0469 (13)	0.0542 (13)	−0.0083 (10)	0.0028 (9)	−0.0053 (10)
O1	0.089 (4)	0.047 (3)	0.123 (6)	−0.012 (3)	0.024 (4)	−0.021 (4)
O2	0.063 (3)	0.105 (4)	0.047 (4)	0.006 (3)	−0.013 (3)	0.000 (4)
C1	0.044 (4)	0.048 (5)	0.044 (4)	0.006 (3)	−0.001 (4)	0.003 (4)
C2	0.060 (5)	0.069 (7)	0.066 (5)	0.025 (5)	0.011 (5)	0.004 (4)
C3	0.055 (5)	0.133 (10)	0.055 (5)	0.038 (6)	0.007 (4)	0.013 (6)
C4	0.045 (5)	0.104 (8)	0.070 (6)	−0.008 (5)	0.009 (4)	−0.011 (6)
C5	0.056 (5)	0.074 (6)	0.097 (7)	−0.006 (5)	0.015 (6)	0.014 (6)
C6	0.050 (4)	0.055 (5)	0.065 (5)	0.000 (4)	0.001 (4)	0.009 (4)
C7	0.040 (4)	0.058 (5)	0.044 (4)	−0.007 (4)	−0.005 (3)	0.007 (4)
C8	0.040 (4)	0.087 (6)	0.058 (6)	−0.018 (4)	−0.003 (4)	0.005 (4)
C9	0.052 (5)	0.047 (4)	0.063 (5)	0.006 (4)	0.009 (4)	0.001 (5)

Geometric parameters (Å, º)

Br—C7	1.935 (7)	C7—C9	1.538 (11)
S1—O1	1.420 (5)	C2—H2	0.9300
S1—O2	1.431 (7)	C3—H3	0.9300
S1—C1	1.757 (7)	C4—H4	0.9300
S1—C7	1.806 (8)	C5—H5	0.9300
C1—C2	1.381 (11)	C6—H6	0.9300
C1—C6	1.391 (10)	C8—H8a	0.9600
C2—C3	1.429 (14)	C8—H8b	0.9600
C3—C4	1.358 (12)	C8—H8c	0.9600
C4—C5	1.351 (13)	C9—H9a	0.9600
C5—C6	1.357 (11)	C9—H9b	0.9600
C7—C8	1.537 (9)	C9—H9c	0.9600
C6···C9	3.469 (12)	O2···C8^ii	3.414 (10)
Br···C2	3.539 (9)	Br···C3^iii	3.555 (10)
O1···C9^i	3.133 (10)
O1—S1—O2	119.5 (5)	C1—C2—H2	121.3
O1—S1—C1	107.8 (4)	C3—C2—H2	121.3
O2—S1—C1	108.5 (3)	C4—C3—H3	120.2
O1—S1—C7	108.5 (4)	C2—C3—H3	120.2
O2—S1—C7	104.6 (3)	C5—C4—H4	119.0
C1—S1—C7	107.3 (3)	C3—C4—H4	119.0
C2—C1—C6	120.4 (7)	C6—C5—H5	120.1
C2—C1—S1	119.5 (6)	C5—C6—H6	119.7
C6—C1—S1	119.9 (6)	C1—C6—H6	119.7
C1—C2—C3	117.5 (9)	C7—C8—H8a	109.5
C4—C3—C2	119.7 (9)	C7—C8—H8b	109.5
C5—C4—C3	121.9 (9)	H8a—C8—H8b	109.5
C4—C5—C6	119.8 (9)	C7—C8—H8c	109.5
C4—C5—H5	120.1	H8a—C8—H8c	109.5
C5—C6—C1	120.7 (8)	H8b—C8—H8c	109.5
C8—C7—C9	113.9 (7)	C7—C9—H9a	109.5
C8—C7—S1	108.4 (5)	C7—C9—H9b	109.5
C9—C7—S1	112.0 (5)	H9a—C9—H9b	109.5
C8—C7—Br	107.4 (5)	C7—C9—H9c	109.5
C9—C7—Br	107.4 (6)	H9a—C9—H9c	109.5
S1—C7—Br	107.5 (4)	H9b—C9—H9c	109.5
O1—S1—C1—C2	−19.8 (8)	C2—C1—C6—C5	−1.9 (13)
O2—S1—C1—C2	−150.6 (7)	S1—C1—C6—C5	−176.6 (7)
C7—S1—C1—C2	96.9 (7)	O1—S1—C7—C8	−59.1 (6)
O1—S1—C1—C6	154.9 (7)	O2—S1—C7—C8	69.6 (6)
O2—S1—C1—C6	24.1 (7)	C1—S1—C7—C8	−175.3 (5)
C7—S1—C1—C6	−88.4 (7)	O1—S1—C7—C9	174.4 (6)
C6—C1—C2—C3	1.9 (13)	O2—S1—C7—C9	−57.0 (6)
S1—C1—C2—C3	176.6 (7)	C1—S1—C7—C9	58.2 (6)
C1—C2—C3—C4	−1.7 (14)	O1—S1—C7—Br	56.7 (5)
C2—C3—C4—C5	1.4 (15)	O2—S1—C7—Br	−174.6 (4)
C3—C4—C5—C6	−1.3 (15)	C1—S1—C7—Br	−59.5 (4)
C4—C5—C6—C1	1.6 (14)

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