2-Bromo-2-propyl 2-(5-tert-butyl-1,3-xylyl) ketone

The 2-bromo-2-propyl (α-bromo­propyl) group in crystalline 2-bromo-2-propyl 2-(5-tert-butyl-1,3-xylyl) ketone, C₁₆H₂₃BrO, exhibits a surprisingly high degree of rotational disorder, although it is freely rotating in solution.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.010 Å
• Disorder in main residue
• R factor = 0.070
• wR factor = 0.261
• Data-to-parameter ratio = 16.2

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



RFACR_01  Alert C The value of the weighted R factor is > 0.25
          Weighted R factor given   0.261

PLAT_213  Alert C Atom  C15    has ADP max/min Ratio ...........       3.30

PLAT_301  Alert C Main Residue Disorder ........................      14.00 Perc.


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 3 Alert Level C = Please check

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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: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: LS in TEXSAN, and SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP in TEXSAN (Johnson, 1965); software used to prepare material for publication: TEXSAN, SHELXL97 and PLATON (Spek, 2000).

2-Bromo-2-propyl 2-(5-tert-butyl-1,3-xylyl) ketone

Crystal data

C16H23BrO	F(000) = 324
Mr = 311.25	Dx = 1.284 Mg m^−3
Triclinic, P1	Melting point = 366–366.5 K
a = 11.669 (4) Å	Mo Kα radiation, λ = 0.71069 Å
b = 11.7771 (16) Å	Cell parameters from 24 reflections
c = 6.1750 (12) Å	θ = 10.0–10.8°
α = 101.711 (14)°	µ = 2.54 mm^−1
β = 95.71 (3)°	T = 296 K
γ = 75.948 (17)°	Prism, colorless
V = 804.9 (4) Å^3	0.48 × 0.29 × 0.10 mm
Z = 2

Data collection

Rigaku AFC-5S diffractometer	1180 reflections with I > 2σ(I)
Radiation source: sealed tube	Rint = 0.023
Graphite monochromator	θmax = 25.1°, θmin = 1.8°
ω scans	h = 0→13
Absorption correction: ψ scan (North, Phillips & Mathews, 1968)	k = −13→13
Tmin = 0.427, Tmax = 0.776	l = −7→7
2997 measured reflections	3 standard reflections every 100 reflections
2842 independent reflections	intensity decay: 11.8%

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.070	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.261	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.128P)^2 + 0.6997P] where P = (Fo^2 + 2Fc^2)/3
2842 reflections	(Δ/σ)max < 0.001
175 parameters	Δρmax = 0.68 e Å^−3
6 restraints	Δρmin = −0.68 e Å^−3

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
Br1	0.0471 (2)	0.2636 (2)	0.8749 (4)	0.0834 (8)	0.3369 (17)
Br2	0.06727 (17)	0.38545 (16)	1.2778 (3)	0.1058 (9)	0.581 (2)
Br3	0.2648 (10)	0.4073 (8)	0.985 (2)	0.1058 (9)	0.082 (2)
O1	0.3222 (4)	0.2258 (4)	1.3101 (8)	0.0768 (15)
C1	0.2747 (5)	0.0798 (5)	1.0113 (10)	0.0451 (15)
C2	0.3552 (5)	0.0391 (5)	0.8441 (10)	0.0469 (15)
C3	0.3659 (6)	−0.0778 (6)	0.7275 (10)	0.0539 (17)
C4	0.3009 (5)	−0.1535 (5)	0.7696 (10)	0.0505 (16)
C5	0.2252 (6)	−0.1098 (6)	0.9406 (11)	0.0568 (17)
C6	0.2095 (5)	0.0048 (5)	1.0641 (10)	0.0495 (16)
C7	0.1266 (7)	0.0447 (6)	1.2535 (12)	0.072 (2)
C8	0.4322 (6)	0.1137 (6)	0.7896 (11)	0.0595 (18)
C9	0.2617 (6)	0.2042 (6)	1.1411 (11)	0.0499 (16)
C10	0.1771 (3)	0.3051 (4)	1.0589 (6)	0.0661 (19)
C11	0.1139 (11)	0.2713 (11)	0.8321 (11)	0.071 (2)*	0.6631 (17)
C12	0.110 (2)	0.3905 (19)	1.253 (3)	0.071 (2)*	0.419 (2)
C13	0.2265 (7)	0.4062 (6)	1.0082 (15)	0.071 (2)*	0.918 (2)
C14	0.3109 (6)	−0.2793 (6)	0.6360 (12)	0.0656 (19)
C15	0.3465 (16)	−0.3673 (8)	0.7823 (19)	0.190 (7)
C16	0.3999 (10)	−0.3099 (8)	0.4551 (16)	0.122 (4)
C17	0.1953 (9)	−0.2864 (9)	0.505 (2)	0.150 (5)
H3	0.4195	−0.1057	0.6163	0.065*
H5	0.1821	−0.1601	0.9751	0.068*
H7a	0.1722	0.0476	1.3920	0.108*
H7b	0.0771	−0.0106	1.2431	0.108*
H7c	0.0782	0.1225	1.2452	0.108*
H8a	0.5073	0.0636	0.7455	0.089*
H8b	0.4440	0.1721	0.9178	0.089*
H8c	0.3946	0.1531	0.6708	0.089*
H11a	0.0634	0.3416	0.7896	0.106*	0.6631 (17)
H11b	0.0671	0.2159	0.8421	0.106*	0.6631 (17)
H11c	0.1717	0.2352	0.7233	0.106*	0.6631 (17)
H12a	0.0566	0.4560	1.1993	0.106*	0.419 (2)
H12b	0.1655	0.4202	1.3619	0.106*	0.419 (2)
H12c	0.0658	0.3486	1.3192	0.106*	0.419 (2)
H13a	0.1723	0.4812	1.0535	0.106*	0.918 (2)
H13b	0.2365	0.3939	0.8520	0.106*	0.918 (2)
H13c	0.3015	0.4066	1.0873	0.106*	0.918 (2)
H15a	0.4201	−0.3587	0.8607	0.284*
H15b	0.3559	−0.4461	0.6954	0.284*
H15c	0.2868	−0.3545	0.8865	0.284*
H16a	0.3775	−0.2531	0.3580	0.184*
H16b	0.4007	−0.3883	0.3719	0.184*
H16c	0.4773	−0.3074	0.5219	0.184*
H17a	0.1764	−0.2271	0.4132	0.226*
H17b	0.1335	−0.2727	0.6056	0.226*
H17c	0.2027	−0.3640	0.4142	0.226*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0775 (17)	0.0759 (16)	0.0887 (17)	−0.0115 (13)	−0.0222 (13)	0.0169 (13)
Br2	0.1097 (16)	0.0846 (11)	0.1125 (13)	0.0302 (10)	0.0580 (11)	0.0320 (9)
Br3	0.1097 (16)	0.0846 (11)	0.1125 (13)	0.0302 (10)	0.0580 (11)	0.0320 (9)
O1	0.084 (4)	0.067 (3)	0.063 (3)	−0.006 (3)	−0.019 (3)	−0.001 (3)
C1	0.044 (3)	0.038 (3)	0.051 (4)	−0.006 (3)	−0.005 (3)	0.012 (3)
C2	0.044 (4)	0.048 (4)	0.048 (4)	−0.006 (3)	−0.002 (3)	0.016 (3)
C3	0.055 (4)	0.056 (4)	0.049 (4)	−0.010 (3)	0.008 (3)	0.005 (3)
C4	0.044 (4)	0.049 (4)	0.057 (4)	−0.010 (3)	0.006 (3)	0.007 (3)
C5	0.056 (4)	0.044 (4)	0.075 (5)	−0.015 (3)	0.008 (4)	0.015 (3)
C6	0.047 (4)	0.045 (4)	0.055 (4)	−0.006 (3)	0.003 (3)	0.013 (3)
C7	0.082 (5)	0.059 (4)	0.077 (5)	−0.009 (4)	0.041 (4)	0.008 (4)
C8	0.066 (4)	0.057 (4)	0.061 (4)	−0.022 (3)	0.013 (3)	0.011 (3)
C9	0.051 (4)	0.051 (4)	0.049 (4)	−0.011 (3)	0.002 (3)	0.014 (3)
C10	0.070 (5)	0.045 (4)	0.080 (5)	−0.010 (3)	−0.005 (4)	0.012 (4)
C14	0.068 (5)	0.054 (4)	0.075 (5)	−0.020 (4)	0.009 (4)	0.002 (4)
C15	0.39 (2)	0.039 (5)	0.117 (8)	0.004 (8)	0.049 (11)	0.012 (5)
C16	0.147 (9)	0.088 (7)	0.119 (8)	−0.041 (6)	0.045 (7)	−0.047 (6)
C17	0.108 (8)	0.096 (8)	0.208 (13)	−0.032 (6)	−0.009 (8)	−0.064 (8)

Geometric parameters (Å, º)

Br1—C10	1.903 (3)	C7—H7b	0.9600
Br2—C10	1.897 (3)	C7—H7c	0.9600
Br3—C10	1.901 (3)	C8—H8a	0.9600
C11—C10	1.541 (3)	C8—H8b	0.9600
C12—C10	1.543 (3)	C8—H8c	0.9600
C13—C10	1.539 (3)	C11—H11a	0.9600
C9—C10	1.490 (8)	C11—H11b	0.9600
O1—C9	1.219 (7)	C11—H11c	0.9600
C1—C2	1.397 (8)	C12—H12a	0.9600
C1—C6	1.399 (8)	C12—H12b	0.9600
C1—C9	1.501 (9)	C12—H12c	0.9600
C2—C3	1.401 (8)	C13—H13a	0.9600
C2—C8	1.503 (8)	C13—H13b	0.9600
C3—C4	1.379 (8)	C13—H13c	0.9600
C4—C5	1.380 (8)	C15—H15a	0.9600
C4—C14	1.526 (9)	C15—H15b	0.9600
C5—C6	1.388 (9)	C15—H15c	0.9600
C6—C7	1.518 (8)	C16—H16a	0.9600
C14—C15	1.470 (12)	C16—H16b	0.9600
C14—C17	1.513 (12)	C16—H16c	0.9600
C14—C16	1.530 (11)	C17—H17a	0.9600
C3—H3	0.9300	C17—H17b	0.9600
C5—H5	0.9300	C17—H17c	0.9600
C7—H7a	0.9600
Br3···O1	3.135 (12)	C8···C10	3.593 (8)
Br2···O1	3.121 (5)	Br2···Br2^i	3.615 (3)
Br1···C6	3.528 (6)	Br1···C17^ii	3.485 (12)
Br3···C8	3.567 (12)	Br3···C15^iii	3.512 (16)
Br1···C7	3.718 (8)	C2···C8^iv	3.588 (9)
C13—C10—C11	98.7 (7)	C10—C12—H12b	109.5
C9—C10—C12	110.0 (11)	H12a—C12—H12b	109.5
C13—C10—C12	90.8 (11)	C10—C12—H12c	109.5
C11—C10—C12	121.6 (12)	H12a—C12—H12c	109.5
C9—C10—Br2	109.6 (3)	H12b—C12—H12c	109.5
C13—C10—Br2	103.0 (4)	C10—C13—H13a	109.5
C11—C10—Br2	111.5 (5)	C10—C13—H13b	109.5
C9—C10—Br3	108.5 (5)	H13a—C13—H13b	109.5
C11—C10—Br3	99.8 (7)	C10—C13—H13c	109.5
C12—C10—Br3	99.3 (11)	H13a—C13—H13c	109.5
C9—C10—Br1	115.2 (4)	H13b—C13—H13c	109.5
C13—C10—Br1	117.4 (5)	C4—C3—H3	118.4
C12—C10—Br1	99.8 (10)	C2—C3—H3	118.4
C2—C1—C6	120.9 (6)	C4—C5—H5	118.1
C2—C1—C9	119.3 (5)	C6—C5—H5	118.1
C6—C1—C9	119.8 (5)	C6—C7—H7a	109.5
C1—C2—C3	117.9 (5)	C6—C7—H7b	109.5
C1—C2—C8	123.0 (5)	H7a—C7—H7b	109.5
C3—C2—C8	119.1 (5)	C6—C7—H7c	109.5
C4—C3—C2	123.1 (6)	H7a—C7—H7c	109.5
C3—C4—C5	116.5 (6)	H7b—C7—H7c	109.5
C3—C4—C14	122.4 (6)	C2—C8—H8a	109.5
C5—C4—C14	121.1 (6)	C2—C8—H8b	109.5
C4—C5—C6	123.9 (6)	H8a—C8—H8b	109.5
C5—C6—C1	117.7 (6)	C2—C8—H8c	109.5
C5—C6—C7	120.5 (6)	H8a—C8—H8c	109.5
C1—C6—C7	121.8 (6)	H8b—C8—H8c	109.5
O1—C9—C10	118.6 (6)	C14—C15—H15a	109.5
O1—C9—C1	121.3 (6)	C14—C15—H15b	109.5
C10—C9—C1	120.0 (5)	H15a—C15—H15b	109.5
C9—C10—C13	118.1 (5)	C14—C15—H15c	109.5
C9—C10—C11	115.0 (6)	H15a—C15—H15c	109.5
C15—C14—C17	113.1 (9)	H15b—C15—H15c	109.5
C15—C14—C4	110.4 (7)	C14—C16—H16a	109.5
C17—C14—C4	109.1 (6)	C14—C16—H16b	109.5
C15—C14—C16	108.6 (8)	H16a—C16—H16b	109.5
C17—C14—C16	102.9 (8)	C14—C16—H16c	109.5
C4—C14—C16	112.6 (6)	H16a—C16—H16c	109.5
C10—C11—H11a	109.5	H16b—C16—H16c	109.5
C10—C11—H11b	109.5	C14—C17—H17a	109.5
H11a—C11—H11b	109.5	C14—C17—H17b	109.5
C10—C11—H11c	109.5	H17a—C17—H17b	109.5
H11a—C11—H11c	109.5	C14—C17—H17c	109.5
H11b—C11—H11c	109.5	H17a—C17—H17c	109.5
C10—C12—H12a	109.5	H17b—C17—H17c	109.5
C6—C1—C2—C3	1.7 (8)	C6—C1—C9—C10	−94.7 (6)
C9—C1—C2—C3	179.4 (6)	O1—C9—C10—C13	57.9 (8)
C6—C1—C2—C8	−176.5 (5)	C1—C9—C10—C13	−119.6 (6)
C9—C1—C2—C8	1.2 (8)	O1—C9—C10—C11	173.9 (7)
C1—C2—C3—C4	0.2 (9)	C1—C9—C10—C11	−3.6 (8)
C8—C2—C3—C4	178.5 (6)	O1—C9—C10—C12	−44.4 (12)
C2—C3—C4—C5	−2.0 (9)	C1—C9—C10—C12	138.1 (11)
C2—C3—C4—C14	178.0 (6)	O1—C9—C10—Br2	−59.6 (6)
C3—C4—C5—C6	1.9 (9)	C1—C9—C10—Br2	122.9 (5)
C14—C4—C5—C6	−178.1 (6)	O1—C9—C10—Br3	63.2 (7)
C4—C5—C6—C1	−0.1 (9)	C1—C9—C10—Br3	−114.3 (6)
C4—C5—C6—C7	−178.4 (6)	O1—C9—C10—Br1	−156.2 (5)
C2—C1—C6—C5	−1.8 (9)	C1—C9—C10—Br1	26.3 (6)
C9—C1—C6—C5	−179.5 (6)	C3—C4—C14—C15	121.7 (10)
C2—C1—C6—C7	176.5 (6)	C5—C4—C14—C15	−58.3 (11)
C9—C1—C6—C7	−1.2 (9)	C3—C4—C14—C17	−113.5 (8)
C2—C1—C9—O1	−89.9 (7)	C5—C4—C14—C17	66.5 (9)
C6—C1—C9—O1	87.9 (8)	C3—C4—C14—C16	0.1 (10)
C2—C1—C9—C10	87.5 (7)	C5—C4—C14—C16	−179.9 (7)

Symmetry codes: (i) −x, −y+1, −z+3; (ii) −x, −y, −z+1; (iii) x, y+1, z; (iv) −x+1, −y, −z+2.