4-[3-(3,4-Di­methoxy­phenyl)­prop-2-enoyl]­phenyl methacryl­ate and 4-[3-(2-bromo­phenyl)­prop-2-enoyl]­phenyl methacryl­ate

Chalcones (α,β-unsaturated ketones) are effective antitumour agents. It has been proved that having halogen or methoxy groups substituted in various positions of the phenyl ring enhances the activity of chalcones many times. The title compounds, C₂₁H₂₀O₅ and C₁₉H₁₅BrO₃, respectively, were chosen for crystallographic study in order to determine their structures and conformations. In both compounds, the keto group is in the s-cis conformation and is almost planar. There are weak intramolecular interactions in both structures.

S1. Comment

Chalcones possess multiprotecting, biochemical, antifungal, antimalarial and antifertility activities. The carbonyl group is a characteristic functional group in chalcones. In recent years, the synthesis of polymers having a photosensitive functional group has been an active field of research in polymer science. Monomers having structures similar to the title compounds, 4-[3-(3,4-dimethoxyphenyl)prop-2-enoyl]phenyl methacrylate, (I), and 4-[3-(2-bromophenyl)prop-2-enoyl]phenyl methacrylate, (II), have been polymerized in solution using free-radical initiators (Balaji et al., 2000; Subramanian et al., 2001). These polymers, containing an α,β-unsaturated carbonyl group, undergo crosslinking upon irradiation with UV light or an electron beam and are being used as photoresistors (Hyder Ali & Srinivasan, 1997; Rehab & Salahuddin, 1999). These photosensitive polymers find application in the fields of integrated circuit technology, printing technology and photocurable coatings (Nagamatzu & Inui, 1977).

The keto group is in an s-cis conformation in compounds (I) and (II), as can be seen from the torsion-angle values [C7—C8—C9—O1 = 4.7 (3)° for (I) and 7.2 (6)° for (II)]. The two phenyl rings make dihedral angles with the keto group of 8.5 (2) and 11.8 (1)° for (I), and 4.8 (2) and 7.6 (2)° for (II). In general, the bond lengths in these conjugated systems are longer than the double bonds and shorter than the single bonds. In both structures, the bond lengths agree with reported values (Carpy et al., 1997). From the torsion angle values C5—C4—C7—C8 = -176.0 (2)°, C4—C7—C8—C9 = 177.5 (2)°, C7—C8—C9—C10 = -173.2 (2)° and C8—C9—C10—C15 = -167.2 (2)° in (I) and C1—C6—C7—C8 = 170.6 (4)°, C6—C7—C8—C9 = 178.9 (3)°, C7—C8—C9—C10 = -173.8 (4)° and C8—C9—C10—C11 = 8.1 (6)° in (II), it is clear that the unsaturated ketone system is not strictly planar. This deviation from planarity affects the π-electron conjugation. The H atoms at C7 and C8 are trans. The opening of the C4—C7—C8 angle to 129.5 (2)° in (I) and the C6—C7—C8 angle to 127.3 (4)° in (II) can be ascribed to the short interatomic non-bonded interaction between atoms H8 and H3 in (I), which are separated by a distance of 2.309 (2) Å, and the interaction between atoms H5 and H8 in (II), which are at a distance of 2.211 (1) Å (Tokuno et al., 1986). This non-bonded interaction also produces an appreciable twist about the C4—C7 bond at the expense of the conjugation energy of the system. The exocyclic angles about C10 reveal deviations from normal trigonal values, with a larger C9—C10—C11 angle [124.1 (2)° for (I) and 123.5 (3)° for (II)] and a smaller C9—C10—C15 angle [117.6 (2)° for (I) and 118.1 (3)° for (II)]. There are two weak C—H···O intramolecular interactions in (I) and (II), and one weak C—H···Br interaction in (II) (Tables 3 and 4).

Displacement-ellipsoid plots of (I) and (II) are shown in Figs. 1 and 2, respectively. Figs. 3 and 4 show the packing of molecules (I) and (II), viewed down the a axis in each case.

S2. Experimental

The syntheses of compounds (I) and (II) consist of two steps. 3,4-Dimethoxystyryl 4'-hydroxyphenyl ketone and 1-bromostyryl 4'-hydroxyphenyl ketone were prepared by the Claissen-Schmidt condensation of 3,4,dimethoxybenzaldehyde or 1-bromobenzaldehyde with 4-hydroxyacetophenone in aqueous alcholol. Compounds (I) and (II) were then prepared by reacting 3,4-dimethoxystyryl 4'-hydroxyphenyl ketone or 1-bromostyryl 4'-hydroxyphenyl ketone in methyl ethyl ketone with methacryloyl chloride in the presence of triethylamine.

S3. Refinement

After checking their presence in the difference map, all H atoms were fixed geometrically and allowed to ride on their attached atoms.

Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989) for (I); SMART (Siemens, 1996) for (II). Cell refinement: CAD-4 Software for (I); SAINT (Siemens, 1996) for (II). Data reduction: SDP (Frenz, 1978) for (I); SAINT for (II). For both compounds, program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL (Sheldrick, 1997). Molecular graphics: ZORTEP (Zsolnai,1997) for (I); SHELXTL for (II). Software used to prepare material for publication: PARST (Nardelli, 1995) and PLATON (Spek, 1990) for (I); SHELXTL, PARST (Nardelli, 1995) and PLATON (Spek, 1990) for (II).

Figures

	Fig. 1. The molecular structure of compound (I) drawn with 30% probability displacement ellipsoids.
	Fig. 2. The molecular structure of compound (II) drawn with 30% probability displacement ellipsoids.
	Fig. 3. Packing diagram of (I) viewed down the a axis.
	Fig. 4. Packing diagram of (II) viewed down the a axis.

(I) 4-[3-(3,4-Dimethoxyphenyl)prop-2-enoyl]phenyl methacrylate

Crystal data

C21H20O5	F(000) = 1488
Mr = 352.37	Dx = 1.286 Mg m^−3
Monoclinic, C2/c	Cu Kα radiation, λ = 1.54180 Å
a = 13.381 (2) Å	Cell parameters from 25 reflections
b = 20.813 (2) Å	θ = 4.1–25.0°
c = 13.881 (2) Å	µ = 0.75 mm^−1
β = 109.68 (1)°	T = 293 K
V = 3640.0 (8) Å^3	Needle, colourless
Z = 8	0.3 × 0.2 × 0.2 mm

Data collection

Enraf-Nonius CAD-4 diffractometer	Rint = 0.050
Radiation source: fine-focus sealed tube	θmax = 72.0°, θmin = 4.1°
Graphite monochromator	h = −2→16
ω/2θ scans	k = 0→25
3812 measured reflections	l = −17→16
3549 independent reflections	3 standard reflections every 200 reflections
2444 reflections with I > 2σ(I)	intensity decay: <0.1%

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)] = 0.054	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.163	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0922P)^2 + 0.6924P] where P = (Fo^2 + 2Fc^2)/3
3549 reflections	(Δ/σ)max < 0.001
238 parameters	Δρmax = 0.27 e Å^−3
0 restraints	Δρmin = −0.22 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.48118 (16)	0.16042 (10)	0.11251 (15)	0.0637 (5)
C10	−0.07604 (15)	0.06351 (10)	0.11849 (14)	0.0613 (5)
O5	0.49370 (12)	0.04848 (7)	0.11396 (13)	0.0766 (4)
C3	0.32772 (16)	0.09852 (9)	0.10879 (15)	0.0608 (5)
H3	0.2951	0.0590	0.1082	0.073*
C2	0.43169 (16)	0.10073 (9)	0.11195 (15)	0.0613 (5)
O4	0.58327 (12)	0.15740 (7)	0.11380 (14)	0.0803 (5)
C4	0.27059 (16)	0.15542 (9)	0.10639 (15)	0.0636 (5)
C9	−0.01194 (16)	0.11840 (10)	0.10340 (16)	0.0682 (5)
O2	−0.26290 (13)	−0.08349 (9)	0.17100 (11)	0.0855 (5)
C13	−0.19997 (17)	−0.03308 (12)	0.15513 (15)	0.0694 (5)
C17	−0.32525 (15)	−0.14995 (9)	0.27588 (17)	0.0662 (5)
C8	0.09742 (16)	0.10715 (10)	0.10483 (15)	0.0651 (5)
H8	0.1227	0.0653	0.1078	0.078*
C16	−0.25796 (16)	−0.09516 (10)	0.26773 (16)	0.0665 (5)
C15	−0.16951 (17)	0.07756 (12)	0.13748 (17)	0.0737 (6)
H15	−0.1904	0.1202	0.1377	0.088*
O1	−0.04908 (14)	0.17312 (8)	0.09273 (17)	0.1000 (6)
C7	0.16029 (17)	0.15598 (10)	0.10187 (16)	0.0672 (5)
H7	0.1293	0.1964	0.0961	0.081*
C11	−0.04766 (16)	−0.00037 (10)	0.11653 (15)	0.0656 (5)
H11	0.0141	−0.0107	0.1033	0.079*
O3	−0.20585 (16)	−0.06307 (9)	0.33833 (13)	0.0983 (6)
C20	0.44644 (19)	−0.01285 (10)	0.1069 (2)	0.0784 (6)
H20A	0.4981	−0.0453	0.1092	0.118*
H20B	0.3883	−0.0161	0.0436	0.118*
H20C	0.4208	−0.0188	0.1631	0.118*
C5	0.32143 (18)	0.21358 (10)	0.10825 (18)	0.0714 (5)
H5	0.2848	0.2516	0.1077	0.086*
C19	−0.3193 (2)	−0.16732 (11)	0.3809 (2)	0.0808 (6)
H19A	−0.3531	−0.2081	0.3799	0.121*
H19B	−0.3546	−0.1351	0.4071	0.121*
H19C	−0.2462	−0.1700	0.4239	0.121*
C6	0.42588 (18)	0.21615 (10)	0.11093 (17)	0.0719 (6)
H6	0.4585	0.2557	0.1117	0.086*
C14	−0.23157 (17)	0.02958 (13)	0.15588 (17)	0.0776 (6)
H14	−0.2938	0.0395	0.1686	0.093*
C18	−0.38625 (19)	−0.18055 (12)	0.1917 (2)	0.0881 (7)
H18A	−0.4282	−0.2150	0.1974	0.106*
H18B	−0.3866	−0.1674	0.1276	0.106*
C21	0.6354 (2)	0.21722 (12)	0.1145 (2)	0.0877 (7)
H21A	0.7059	0.2095	0.1138	0.132*
H21B	0.6392	0.2408	0.1751	0.132*
H21C	0.5963	0.2417	0.0552	0.132*
C12	−0.10995 (18)	−0.04891 (11)	0.13405 (16)	0.0705 (5)
H12	−0.0911	−0.0917	0.1316	0.085*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0659 (11)	0.0603 (11)	0.0645 (12)	−0.0067 (9)	0.0217 (9)	0.0041 (9)
C10	0.0554 (10)	0.0722 (12)	0.0520 (10)	0.0076 (9)	0.0124 (8)	0.0071 (8)
O5	0.0688 (9)	0.0556 (8)	0.1095 (12)	−0.0026 (6)	0.0353 (8)	−0.0002 (7)
C3	0.0652 (11)	0.0557 (10)	0.0615 (11)	−0.0059 (8)	0.0214 (9)	0.0025 (8)
C2	0.0665 (11)	0.0555 (10)	0.0619 (11)	−0.0016 (8)	0.0216 (9)	0.0018 (8)
O4	0.0705 (9)	0.0656 (9)	0.1086 (12)	−0.0092 (7)	0.0351 (8)	0.0071 (8)
C4	0.0681 (12)	0.0617 (11)	0.0599 (11)	−0.0002 (9)	0.0200 (9)	0.0040 (9)
C9	0.0654 (11)	0.0675 (12)	0.0693 (12)	0.0137 (10)	0.0195 (9)	0.0131 (10)
O2	0.0815 (10)	0.1059 (12)	0.0691 (9)	−0.0348 (9)	0.0254 (8)	−0.0158 (8)
C13	0.0623 (11)	0.0908 (15)	0.0520 (11)	−0.0138 (10)	0.0152 (9)	−0.0061 (10)
C17	0.0547 (10)	0.0593 (11)	0.0897 (15)	0.0040 (8)	0.0310 (10)	−0.0089 (10)
C8	0.0643 (11)	0.0659 (12)	0.0646 (12)	0.0069 (9)	0.0209 (9)	0.0086 (9)
C16	0.0594 (11)	0.0746 (13)	0.0665 (12)	−0.0033 (9)	0.0226 (9)	−0.0085 (10)
C15	0.0591 (11)	0.0815 (14)	0.0784 (14)	0.0144 (10)	0.0202 (10)	0.0080 (11)
O1	0.0795 (10)	0.0739 (11)	0.1498 (18)	0.0194 (8)	0.0429 (11)	0.0263 (10)
C7	0.0686 (12)	0.0651 (12)	0.0671 (12)	0.0078 (9)	0.0219 (10)	0.0074 (9)
C11	0.0607 (11)	0.0759 (13)	0.0620 (11)	0.0039 (9)	0.0230 (9)	0.0017 (9)
O3	0.1109 (13)	0.1109 (13)	0.0701 (10)	−0.0475 (11)	0.0266 (9)	−0.0144 (9)
C20	0.0723 (13)	0.0567 (12)	0.1021 (17)	−0.0018 (10)	0.0238 (12)	0.0013 (11)
C5	0.0789 (14)	0.0558 (11)	0.0797 (14)	0.0039 (10)	0.0271 (11)	0.0043 (10)
C19	0.0787 (14)	0.0681 (13)	0.1035 (18)	0.0066 (11)	0.0411 (13)	0.0042 (12)
C6	0.0788 (14)	0.0579 (11)	0.0785 (14)	−0.0111 (10)	0.0259 (11)	0.0021 (10)
C14	0.0559 (11)	0.1020 (18)	0.0739 (14)	0.0020 (11)	0.0204 (10)	−0.0010 (12)
C18	0.0767 (14)	0.0794 (15)	0.113 (2)	−0.0158 (12)	0.0383 (14)	−0.0282 (14)
C21	0.0797 (15)	0.0717 (14)	0.116 (2)	−0.0169 (11)	0.0388 (14)	0.0087 (13)
C12	0.0728 (13)	0.0740 (13)	0.0655 (12)	−0.0033 (10)	0.0243 (10)	−0.0035 (10)

Geometric parameters (Å, º)

C1—O4	1.362 (3)	C8—H8	0.9300
C1—C6	1.372 (3)	C16—O3	1.197 (2)
C1—C2	1.407 (3)	C15—C14	1.377 (3)
C10—C11	1.386 (3)	C15—H15	0.9300
C10—C15	1.393 (3)	C7—H7	0.9300
C10—C9	1.485 (3)	C11—C12	1.382 (3)
O5—C2	1.363 (2)	C11—H11	0.9300
O5—C20	1.413 (2)	C20—H20A	0.9600
C3—C2	1.378 (3)	C20—H20B	0.9600
C3—C4	1.404 (3)	C20—H20C	0.9600
C3—H3	0.9300	C5—C6	1.387 (3)
O4—C21	1.426 (3)	C5—H5	0.9300
C4—C5	1.385 (3)	C19—H19A	0.9600
C4—C7	1.456 (3)	C19—H19B	0.9600
C9—O1	1.231 (2)	C19—H19C	0.9600
C9—C8	1.475 (3)	C6—H6	0.9300
O2—C16	1.344 (3)	C14—H14	0.9300
O2—C13	1.408 (3)	C18—H18A	0.9300
C13—C14	1.372 (3)	C18—H18B	0.9300
C13—C12	1.372 (3)	C21—H21A	0.9600
C17—C18	1.340 (3)	C21—H21B	0.9600
C17—C19	1.477 (3)	C21—H21C	0.9600
C17—C16	1.481 (3)	C12—H12	0.9300
C8—C7	1.329 (3)
O4—C1—C6	124.93 (18)	C4—C7—H7	115.3
O4—C1—C2	115.32 (18)	C12—C11—C10	120.82 (19)
C6—C1—C2	119.75 (19)	C12—C11—H11	119.6
C11—C10—C15	118.3 (2)	C10—C11—H11	119.6
C11—C10—C9	124.07 (18)	O5—C20—H20A	109.5
C15—C10—C9	117.59 (19)	O5—C20—H20B	109.5
C2—O5—C20	117.66 (16)	H20A—C20—H20B	109.5
C2—C3—C4	120.57 (17)	O5—C20—H20C	109.5
C2—C3—H3	119.7	H20A—C20—H20C	109.5
C4—C3—H3	119.7	H20B—C20—H20C	109.5
O5—C2—C3	125.13 (17)	C4—C5—C6	121.25 (19)
O5—C2—C1	114.99 (17)	C4—C5—H5	119.4
C3—C2—C1	119.87 (18)	C6—C5—H5	119.4
C1—O4—C21	116.50 (17)	C17—C19—H19A	109.5
C5—C4—C3	118.48 (19)	C17—C19—H19B	109.5
C5—C4—C7	118.57 (19)	H19A—C19—H19B	109.5
C3—C4—C7	122.95 (18)	C17—C19—H19C	109.5
O1—C9—C8	120.4 (2)	H19A—C19—H19C	109.5
O1—C9—C10	119.96 (19)	H19B—C19—H19C	109.5
C8—C9—C10	119.56 (18)	C1—C6—C5	120.07 (19)
C16—O2—C13	117.39 (16)	C1—C6—H6	120.0
C14—C13—C12	121.7 (2)	C5—C6—H6	120.0
C14—C13—O2	120.3 (2)	C13—C14—C15	118.8 (2)
C12—C13—O2	117.9 (2)	C13—C14—H14	120.6
C18—C17—C19	124.0 (2)	C15—C14—H14	120.6
C18—C17—C16	120.5 (2)	C17—C18—H18A	120.0
C19—C17—C16	115.56 (19)	C17—C18—H18B	120.0
C7—C8—C9	120.91 (19)	H18A—C18—H18B	120.0
C7—C8—H8	119.5	O4—C21—H21A	109.5
C9—C8—H8	119.5	O4—C21—H21B	109.5
O3—C16—O2	122.4 (2)	H21A—C21—H21B	109.5
O3—C16—C17	124.7 (2)	O4—C21—H21C	109.5
O2—C16—C17	112.88 (18)	H21A—C21—H21C	109.5
C14—C15—C10	121.3 (2)	H21B—C21—H21C	109.5
C14—C15—H15	119.4	C13—C12—C11	119.1 (2)
C10—C15—H15	119.4	C13—C12—H12	120.4
C8—C7—C4	129.5 (2)	C11—C12—H12	120.4
C8—C7—H7	115.3
C20—O5—C2—C3	3.5 (3)	C18—C17—C16—O3	175.7 (2)
C20—O5—C2—C1	−176.04 (19)	C19—C17—C16—O3	−4.5 (3)
C4—C3—C2—O5	−179.67 (18)	C18—C17—C16—O2	−2.8 (3)
C4—C3—C2—C1	−0.2 (3)	C19—C17—C16—O2	177.09 (18)
O4—C1—C2—O5	0.7 (3)	C11—C10—C15—C14	1.2 (3)
C6—C1—C2—O5	−179.81 (18)	C9—C10—C15—C14	−177.7 (2)
O4—C1—C2—C3	−178.84 (18)	C9—C8—C7—C4	177.5 (2)
C6—C1—C2—C3	0.6 (3)	C5—C4—C7—C8	−176.0 (2)
C6—C1—O4—C21	0.6 (3)	C3—C4—C7—C8	4.1 (4)
C2—C1—O4—C21	−179.93 (19)	C15—C10—C11—C12	−0.7 (3)
C2—C3—C4—C5	−0.6 (3)	C9—C10—C11—C12	178.19 (19)
C2—C3—C4—C7	179.30 (19)	C3—C4—C5—C6	0.9 (3)
C11—C10—C9—O1	170.4 (2)	C7—C4—C5—C6	−179.0 (2)
C15—C10—C9—O1	−10.8 (3)	O4—C1—C6—C5	179.1 (2)
C11—C10—C9—C8	−11.7 (3)	C2—C1—C6—C5	−0.3 (3)
C15—C10—C9—C8	167.17 (19)	C4—C5—C6—C1	−0.5 (3)
C16—O2—C13—C14	−78.2 (3)	C12—C13—C14—C15	−1.7 (3)
C16—O2—C13—C12	105.0 (2)	O2—C13—C14—C15	−178.35 (18)
O1—C9—C8—C7	4.7 (3)	C10—C15—C14—C13	−0.1 (3)
C10—C9—C8—C7	−173.18 (19)	C14—C13—C12—C11	2.2 (3)
C13—O2—C16—O3	2.8 (3)	O2—C13—C12—C11	178.98 (18)
C13—O2—C16—C17	−178.71 (18)	C10—C11—C12—C13	−1.0 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7···O1	0.93	2.42	2.784 (3)	103
C18—H18B···O2	0.93	2.34	2.685 (3)	101

(II) 4-[3-(2-bromophenyl)prop-2-enoyl]phenyl methacrylate

Crystal data

C19H15BrO3	Z = 2
Mr = 371.22	F(000) = 376
Triclinic, P1	Dx = 1.502 Mg m^−3
a = 7.5272 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.1940 (4) Å	Cell parameters from 4174 reflections
c = 11.5780 (4) Å	θ = 1.8–29.5°
α = 96.227 (1)°	µ = 2.52 mm^−1
β = 98.428 (1)°	T = 293 K
γ = 108.763 (1)°	Block, light yellow
V = 820.54 (5) Å^3	0.44 × 0.32 × 0.12 mm

Data collection

Siemens SMART CCD area-detector diffractometer	2840 independent reflections
Radiation source: fine-focus sealed tube	2355 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.052
Detector resolution: 8.33 pixels mm^-1	θmax = 25.0°, θmin = 1.8°
ω scans	h = −8→8
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	k = −12→8
Tmin = 0.404, Tmax = 0.752	l = −13→13
4721 measured reflections

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)] = 0.056	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.146	H-atom parameters constrained
S = 0.99	w = 1/[σ^2(Fo^2) + (0.0895P)^2] where P = (Fo^2 + 2Fc^2)/3
2840 reflections	(Δ/σ)max < 0.001
209 parameters	Δρmax = 0.58 e Å^−3
2 restraints	Δρmin = −1.08 e Å^−3

Special details

Experimental. The data collection covered over a hemisphere of reciprocal space by a combination of three sets of exposures; each set had a different ϕ angle (0, 88 and 180°) for the crystal and each exposure of 10 s covered 0.3° in ω. The crystal-to-detector distance was 4 cm and the detector swing angle was -35°. Crystal decay was monitored by repeating fifty initial frames at the end of data collection and analysing the intensity of duplicate reflections, and was found to be negligible.

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 (Ų)

	x	y	z	Uiso*/Ueq
Br1	−0.40576 (6)	−0.15977 (4)	−0.03665 (4)	0.0564 (2)
O1	0.2418 (4)	−0.0783 (4)	0.1754 (3)	0.0716 (10)
O2	0.8047 (4)	−0.1698 (4)	0.5954 (3)	0.0610 (8)
O3	0.8349 (5)	−0.3662 (4)	0.5073 (3)	0.0698 (9)
C1	−0.4797 (5)	−0.2994 (4)	0.0605 (3)	0.0404 (8)
C2	−0.6723 (6)	−0.3763 (5)	0.0457 (4)	0.0533 (10)
H2A	−0.7599	−0.3597	−0.0112	0.064*
C3	−0.7355 (6)	−0.4774 (5)	0.1147 (4)	0.0575 (11)
H3A	−0.8648	−0.5300	0.1038	0.069*
C4	−0.6045 (6)	−0.4998 (5)	0.2003 (4)	0.0559 (11)
H4A	−0.6457	−0.5674	0.2476	0.067*
C5	−0.4135 (6)	−0.4222 (4)	0.2153 (3)	0.0458 (9)
H5A	−0.3276	−0.4378	0.2740	0.055*
C6	−0.3438 (5)	−0.3211 (4)	0.1458 (3)	0.0378 (8)
C7	−0.1388 (5)	−0.2422 (4)	0.1599 (3)	0.0416 (8)
H7A	−0.1024	−0.1881	0.1020	0.050*
C8	−0.0002 (5)	−0.2395 (4)	0.2455 (3)	0.0459 (9)
H8A	−0.0300	−0.2907	0.3061	0.055*
C9	0.2024 (5)	−0.1559 (4)	0.2467 (4)	0.0436 (9)
C10	0.3567 (5)	−0.1671 (4)	0.3382 (3)	0.0384 (8)
C11	0.3250 (6)	−0.2649 (4)	0.4151 (3)	0.0472 (9)
H11A	0.2020	−0.3271	0.4112	0.057*
C12	0.4750 (6)	−0.2705 (5)	0.4973 (4)	0.0548 (10)
H12A	0.4539	−0.3372	0.5472	0.066*
C13	0.6548 (5)	−0.1763 (4)	0.5039 (3)	0.0455 (9)
C14	0.6911 (6)	−0.0798 (5)	0.4292 (4)	0.0526 (10)
H14A	0.8146	−0.0177	0.4345	0.063*
C15	0.5430 (5)	−0.0756 (4)	0.3463 (4)	0.0501 (10)
H15A	0.5674	−0.0107	0.2948	0.060*
C16	0.8803 (5)	−0.2743 (4)	0.5912 (3)	0.0424 (9)
C17	1.0245 (5)	−0.2530 (4)	0.7005 (3)	0.0445 (9)
C18	1.0487 (7)	−0.1542 (5)	0.7963 (4)	0.0649 (13)
H18A	1.1360	−0.1466	0.8646	0.078*
H18C	0.9780	−0.0943	0.7933	0.078*
C19	1.1292 (7)	−0.3521 (5)	0.6967 (4)	0.0631 (12)
H19A	1.2521	−0.3104	0.7482	0.095*
H19B	1.1461	−0.3741	0.6172	0.095*
H19C	1.0581	−0.4367	0.7222	0.095*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0533 (3)	0.0556 (3)	0.0546 (3)	0.0156 (2)	−0.0086 (2)	0.0209 (2)
O1	0.0464 (18)	0.086 (2)	0.089 (2)	0.0188 (17)	0.0099 (17)	0.057 (2)
O2	0.0484 (17)	0.065 (2)	0.0609 (18)	0.0271 (15)	−0.0204 (14)	−0.0057 (15)
O3	0.078 (2)	0.084 (2)	0.0485 (17)	0.0455 (19)	−0.0129 (15)	−0.0075 (16)
C1	0.041 (2)	0.042 (2)	0.0356 (18)	0.0154 (16)	−0.0013 (16)	0.0040 (15)
C2	0.039 (2)	0.068 (3)	0.046 (2)	0.017 (2)	−0.0062 (17)	0.0045 (19)
C3	0.038 (2)	0.070 (3)	0.052 (2)	0.006 (2)	0.0011 (19)	0.007 (2)
C4	0.049 (3)	0.061 (3)	0.053 (2)	0.010 (2)	0.011 (2)	0.014 (2)
C5	0.043 (2)	0.051 (2)	0.044 (2)	0.0174 (18)	0.0034 (17)	0.0136 (17)
C6	0.0357 (19)	0.040 (2)	0.0367 (18)	0.0158 (16)	0.0009 (15)	0.0028 (14)
C7	0.036 (2)	0.045 (2)	0.046 (2)	0.0169 (17)	0.0038 (16)	0.0141 (16)
C8	0.0336 (19)	0.057 (2)	0.048 (2)	0.0141 (17)	0.0045 (17)	0.0190 (17)
C9	0.038 (2)	0.049 (2)	0.049 (2)	0.0206 (18)	0.0060 (17)	0.0143 (17)
C10	0.0318 (18)	0.040 (2)	0.044 (2)	0.0152 (15)	0.0027 (16)	0.0059 (15)
C11	0.0347 (19)	0.054 (2)	0.051 (2)	0.0133 (17)	−0.0001 (17)	0.0174 (18)
C12	0.047 (2)	0.064 (3)	0.053 (2)	0.020 (2)	−0.0016 (19)	0.020 (2)
C13	0.039 (2)	0.051 (2)	0.043 (2)	0.0211 (18)	−0.0087 (17)	0.0000 (17)
C14	0.031 (2)	0.052 (3)	0.066 (3)	0.0085 (18)	−0.0025 (19)	0.008 (2)
C15	0.038 (2)	0.050 (2)	0.060 (2)	0.0118 (18)	0.0071 (19)	0.0163 (18)
C16	0.0311 (18)	0.049 (2)	0.046 (2)	0.0106 (16)	0.0043 (16)	0.0163 (17)
C17	0.0332 (19)	0.052 (2)	0.042 (2)	0.0053 (17)	0.0003 (16)	0.0166 (17)
C18	0.064 (3)	0.067 (3)	0.054 (3)	0.026 (2)	−0.017 (2)	−0.001 (2)
C19	0.059 (3)	0.079 (3)	0.056 (3)	0.036 (2)	−0.003 (2)	0.013 (2)

Geometric parameters (Å, º)

Br1—C1	1.903 (4)	C9—C10	1.495 (5)
O1—C9	1.207 (5)	C10—C11	1.395 (5)
O2—C16	1.359 (5)	C10—C15	1.395 (5)
O2—C13	1.410 (5)	C11—C12	1.386 (6)
O3—C16	1.199 (5)	C11—H11A	0.9300
C1—C2	1.383 (6)	C12—C13	1.370 (6)
C1—C6	1.403 (5)	C12—H12A	0.9300
C2—C3	1.379 (7)	C13—C14	1.368 (6)
C2—H2A	0.9300	C14—C15	1.376 (6)
C3—C4	1.383 (6)	C14—H14A	0.9300
C3—H3A	0.9300	C15—H15A	0.9300
C4—C5	1.375 (6)	C16—C17	1.487 (5)
C4—H4A	0.9300	C17—C18	1.363 (4)
C5—C6	1.393 (5)	C17—C19	1.469 (4)
C5—H5A	0.9300	C18—H18A	0.9300
C6—C7	1.468 (5)	C18—H18C	0.9300
C7—C8	1.320 (5)	C19—H19A	0.9600
C7—H7A	0.9300	C19—H19B	0.9600
C8—C9	1.486 (5)	C19—H19C	0.9600
C8—H8A	0.9300
C16—O2—C13	119.2 (3)	C12—C11—C10	120.7 (4)
C2—C1—C6	121.3 (4)	C12—C11—H11A	119.7
C2—C1—Br1	117.6 (3)	C10—C11—H11A	119.7
C6—C1—Br1	121.0 (3)	C13—C12—C11	119.1 (4)
C3—C2—C1	120.5 (4)	C13—C12—H12A	120.5
C3—C2—H2A	119.8	C11—C12—H12A	120.5
C1—C2—H2A	119.8	C14—C13—C12	121.7 (4)
C2—C3—C4	119.3 (4)	C14—C13—O2	118.2 (4)
C2—C3—H3A	120.3	C12—C13—O2	119.9 (4)
C4—C3—H3A	120.3	C13—C14—C15	119.3 (4)
C5—C4—C3	119.9 (4)	C13—C14—H14A	120.4
C5—C4—H4A	120.0	C15—C14—H14A	120.4
C3—C4—H4A	120.0	C14—C15—C10	121.0 (4)
C4—C5—C6	122.4 (4)	C14—C15—H15A	119.5
C4—C5—H5A	118.8	C10—C15—H15A	119.5
C6—C5—H5A	118.8	O3—C16—O2	122.1 (4)
C5—C6—C1	116.6 (3)	O3—C16—C17	127.4 (4)
C5—C6—C7	121.9 (3)	O2—C16—C17	110.4 (3)
C1—C6—C7	121.5 (3)	C18—C17—C19	124.0 (4)
C8—C7—C6	127.3 (4)	C18—C17—C16	122.2 (3)
C8—C7—H7A	116.3	C19—C17—C16	113.7 (3)
C6—C7—H7A	116.3	C17—C18—H18A	120.0
C7—C8—C9	121.1 (4)	C17—C18—H18C	120.0
C7—C8—H8A	119.4	H18A—C18—H18C	120.0
C9—C8—H8A	119.4	C17—C19—H19A	109.5
O1—C9—C8	120.3 (4)	C17—C19—H19B	109.5
O1—C9—C10	120.3 (4)	H19A—C19—H19B	109.5
C8—C9—C10	119.4 (3)	C17—C19—H19C	109.5
C11—C10—C15	118.2 (4)	H19A—C19—H19C	109.5
C11—C10—C9	123.6 (3)	H19B—C19—H19C	109.5
C15—C10—C9	118.2 (4)
C6—C1—C2—C3	−0.3 (6)	C8—C9—C10—C15	−172.5 (3)
Br1—C1—C2—C3	−178.9 (3)	C15—C10—C11—C12	0.1 (6)
C1—C2—C3—C4	1.0 (7)	C9—C10—C11—C12	179.5 (4)
C2—C3—C4—C5	−0.4 (7)	C10—C11—C12—C13	1.5 (6)
C3—C4—C5—C6	−0.9 (6)	C11—C12—C13—C14	−2.0 (6)
C4—C5—C6—C1	1.5 (5)	C11—C12—C13—O2	172.8 (3)
C4—C5—C6—C7	−177.9 (4)	C16—O2—C13—C14	−111.7 (4)
C2—C1—C6—C5	−0.9 (5)	C16—O2—C13—C12	73.3 (5)
Br1—C1—C6—C5	177.7 (3)	C12—C13—C14—C15	0.9 (6)
C2—C1—C6—C7	178.5 (4)	O2—C13—C14—C15	−174.0 (3)
Br1—C1—C6—C7	−3.0 (5)	C13—C14—C15—C10	0.7 (6)
C5—C6—C7—C8	−10.1 (6)	C11—C10—C15—C14	−1.1 (6)
C1—C6—C7—C8	170.6 (4)	C9—C10—C15—C14	179.4 (4)
C6—C7—C8—C9	178.9 (3)	C13—O2—C16—O3	6.3 (6)
C7—C8—C9—O1	7.2 (6)	C13—O2—C16—C17	−175.3 (3)
C7—C8—C9—C10	−173.8 (4)	O3—C16—C17—C18	−172.2 (5)
O1—C9—C10—C11	−172.9 (4)	O2—C16—C17—C18	9.6 (6)
C8—C9—C10—C11	8.1 (6)	O3—C16—C17—C19	5.1 (6)
O1—C9—C10—C15	6.5 (6)	O2—C16—C17—C19	−173.1 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7A···Br1	0.93	2.71	3.175 (4)	112
C7—H7A···O1	0.93	2.44	2.781 (5)	101
C18—H18C···O2	0.93	2.38	2.700 (6)	100