A twofold interpenetrated two-dimensional zinc(II) coordination polymer for the highly sensitive detection of nitro­furan­toin in aqueous medium

A novel Zn^II coordination polymer, namely, poly[{μ₂-bis­[4-(2-methyl-1H-imidazol-1-yl)phen­yl]methanone-κ²N³:N^3′}(μ₂-5-bromo­ben­zene-1,3-di­carboxyl­ato-κ²O¹:O³)zinc(II)], [Zn(C₈H₃BrO₄)(C₂₁H₁₈N₄O)]_n or [Zn(Br-BDC)(MIPMO)]_n, (I), has been synthesized by the solvothermal method using 5-bromo­iso­phthalic acid (Br-H₂BDC), bis­[4-(2-methyl-1H-imidazol-1-yl)phen­yl]methanone (MIPMO) and Zn(NO₃)₂·6H₂O. Structure analysis showed that com­pound (I) displays twofold parallel inter­woven sql nets. Fluorescence experiments confirmed that the com­pound can sensitively and selectively detect nitro­furan­toin (NFT) in aqueous medium. In addition, the possible fluorescence quenching mechanisms of com­pound (I) toward NFT are investigated.

Computing details

Poly[{µ₂-bis[4-(2-methyl-1H-imidazol-1-yl)phenyl]methanone-κ²N³:N^3'}(µ₂-5-bromobenzene-1,3-dicarboxylato-κ²O¹:O³)zinc(II)]

Crystal data

[Zn(C8H3BrO4)(C21H18N4O)]	F(000) = 1312
Mr = 650.79	Dx = 1.565 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 9.730 (5) Å	Cell parameters from 9213 reflections
b = 16.520 (9) Å	θ = 27.9–2.6°
c = 17.649 (10) Å	µ = 2.38 mm^−1
β = 103.19 (2)°	T = 293 K
V = 2762 (3) Å^3	Block, colorless
Z = 4	0.19 × 0.18 × 0.17 mm

Data collection

Bruker APEXII CCD diffractometer	4729 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.033
Absorption correction: multi-scan (SADABS; Bruker, 2016)	θmax = 26.0°, θmin = 2.7°
Tmin = 0.574, Tmax = 0.746	h = −12→12
49055 measured reflections	k = −20→20
5414 independent reflections	l = −21→21

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.036	H-atom parameters constrained
wR(F^2) = 0.100	w = 1/[σ^2(Fo^2) + (0.0506P)^2 + 3.4737P] where P = (Fo^2 + 2Fc^2)/3
S = 1.02	(Δ/σ)max < 0.001
5414 reflections	Δρmax = 1.67 e Å^−3
363 parameters	Δρmin = −0.44 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

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

	x	y	z	Uiso*/Ueq
Br1	0.80325 (4)	0.39453 (3)	−0.00985 (2)	0.06071 (14)
Zn1	0.64911 (3)	0.07383 (2)	0.23045 (2)	0.03041 (10)
O1	0.7064 (2)	0.17720 (12)	0.19595 (12)	0.0407 (5)
O5	0.1915 (3)	0.29606 (19)	0.64997 (13)	0.0715 (8)
O2	0.8412 (3)	0.2035 (2)	0.31072 (15)	0.0860 (11)
O3	1.2198 (3)	0.41302 (17)	0.33033 (14)	0.0659 (8)
O4	1.2037 (3)	0.49661 (16)	0.23089 (14)	0.0624 (7)
N4	−0.5036 (2)	0.54715 (14)	0.36843 (13)	0.0336 (5)
N1	0.5422 (3)	0.06977 (14)	0.31469 (14)	0.0355 (5)
N2	0.4037 (3)	0.09600 (15)	0.39234 (15)	0.0390 (6)
N3	−0.3168 (2)	0.49910 (14)	0.44966 (13)	0.0337 (5)
C6	0.8734 (3)	0.36893 (19)	0.09671 (16)	0.0382 (6)
C7	0.8114 (3)	0.30714 (18)	0.12851 (16)	0.0363 (6)
H7	0.7353	0.2790	0.0985	0.044*
C2	0.8634 (3)	0.28704 (17)	0.20612 (16)	0.0344 (6)
C1	0.8008 (3)	0.21777 (19)	0.24224 (17)	0.0400 (7)
C11	0.5245 (4)	0.00012 (18)	0.35423 (18)	0.0458 (7)
H11	0.5660	−0.0496	0.3488	0.055*
C12	0.4381 (4)	0.01528 (18)	0.4016 (2)	0.0497 (8)
H12	0.4075	−0.0214	0.4343	0.060*
C10	0.4687 (3)	0.12690 (17)	0.33922 (16)	0.0357 (6)
C9	0.4582 (4)	0.2126 (2)	0.3144 (2)	0.0582 (9)
H9A	0.5415	0.2275	0.2972	0.087*
H9B	0.4497	0.2463	0.3575	0.087*
H9C	0.3767	0.2197	0.2726	0.087*
C13	0.3314 (3)	0.14186 (18)	0.44010 (17)	0.0385 (6)
C18	0.1896 (3)	0.1584 (2)	0.41518 (19)	0.0466 (7)
H18	0.1378	0.1373	0.3685	0.056*
C17	0.1256 (3)	0.2069 (2)	0.46097 (19)	0.0458 (7)
H17	0.0301	0.2191	0.4448	0.055*
C16	0.2032 (3)	0.23747 (18)	0.53071 (17)	0.0377 (6)
C15	0.3442 (3)	0.21629 (18)	0.55651 (17)	0.0402 (7)
H15	0.3951	0.2340	0.6048	0.048*
C14	0.4084 (3)	0.16931 (19)	0.51076 (18)	0.0418 (7)
H14	0.5034	0.1560	0.5273	0.050*
C19	0.1427 (3)	0.2943 (2)	0.58072 (18)	0.0437 (7)
C20	0.0259 (3)	0.34936 (18)	0.54439 (16)	0.0359 (6)
C25	0.0046 (3)	0.37558 (19)	0.46738 (17)	0.0383 (6)
H25	0.0650	0.3585	0.4367	0.046*
C24	−0.1064 (3)	0.42685 (18)	0.43677 (16)	0.0373 (6)
H24	−0.1192	0.4456	0.3860	0.045*
C23	−0.1979 (3)	0.45003 (17)	0.48171 (16)	0.0336 (6)
C22	−0.1736 (3)	0.42786 (18)	0.55926 (17)	0.0372 (6)
H22	−0.2327	0.4462	0.5903	0.045*
C21	−0.0610 (3)	0.37836 (18)	0.58984 (17)	0.0388 (6)
H21	−0.0432	0.3642	0.6422	0.047*
C28	−0.3609 (3)	0.56550 (18)	0.48537 (17)	0.0367 (6)
H28	−0.3202	0.5860	0.5344	0.044*
C29	−0.4749 (3)	0.59433 (17)	0.43441 (17)	0.0357 (6)
H29	−0.5267	0.6395	0.4426	0.043*
C27	−0.4069 (3)	0.48934 (17)	0.37973 (16)	0.0345 (6)
C26	−0.4056 (4)	0.4208 (2)	0.3263 (2)	0.0548 (9)
H26A	−0.5008	0.4053	0.3028	0.082*
H26B	−0.3568	0.3759	0.3548	0.082*
H26C	−0.3583	0.4367	0.2865	0.082*
C3	0.9777 (3)	0.32947 (18)	0.24916 (16)	0.0361 (6)
H3	1.0135	0.3157	0.3010	0.043*
C4	1.0394 (3)	0.39163 (18)	0.21671 (16)	0.0359 (6)
C8	1.1644 (3)	0.43647 (19)	0.26470 (18)	0.0407 (7)
C5	0.9861 (3)	0.41201 (18)	0.13955 (17)	0.0395 (7)
H5	1.0257	0.4542	0.1169	0.047*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0464 (2)	0.0958 (3)	0.03640 (18)	−0.00140 (18)	0.00221 (14)	0.01806 (17)
Zn1	0.02823 (17)	0.03136 (17)	0.03169 (17)	0.00148 (12)	0.00694 (12)	−0.00090 (12)
O1	0.0395 (11)	0.0411 (11)	0.0405 (11)	−0.0139 (9)	0.0070 (9)	−0.0032 (9)
O5	0.0729 (17)	0.104 (2)	0.0352 (13)	0.0491 (16)	0.0079 (11)	0.0015 (13)
O2	0.096 (2)	0.105 (2)	0.0442 (14)	−0.0616 (19)	−0.0100 (14)	0.0226 (15)
O3	0.0710 (17)	0.0769 (18)	0.0415 (13)	−0.0371 (14)	−0.0045 (12)	−0.0003 (12)
O4	0.0594 (15)	0.0634 (16)	0.0567 (14)	−0.0345 (13)	−0.0024 (12)	0.0088 (12)
N4	0.0306 (11)	0.0326 (12)	0.0361 (12)	0.0019 (9)	0.0041 (9)	0.0000 (10)
N1	0.0401 (13)	0.0330 (12)	0.0347 (12)	0.0028 (10)	0.0113 (10)	0.0012 (10)
N2	0.0433 (14)	0.0361 (13)	0.0420 (13)	0.0032 (10)	0.0186 (11)	0.0006 (10)
N3	0.0274 (11)	0.0378 (12)	0.0348 (12)	0.0036 (9)	0.0050 (9)	0.0010 (10)
C6	0.0344 (14)	0.0494 (17)	0.0292 (13)	0.0018 (13)	0.0037 (11)	0.0030 (12)
C7	0.0285 (13)	0.0424 (15)	0.0359 (14)	−0.0053 (12)	0.0031 (11)	−0.0048 (12)
C2	0.0335 (14)	0.0376 (15)	0.0324 (14)	−0.0070 (11)	0.0080 (11)	−0.0033 (11)
C1	0.0394 (16)	0.0433 (16)	0.0366 (15)	−0.0113 (13)	0.0072 (12)	0.0002 (13)
C11	0.065 (2)	0.0305 (15)	0.0474 (17)	0.0080 (14)	0.0252 (16)	0.0038 (13)
C12	0.074 (2)	0.0314 (15)	0.0526 (19)	0.0008 (15)	0.0320 (17)	0.0045 (13)
C10	0.0381 (15)	0.0347 (14)	0.0354 (14)	0.0029 (12)	0.0107 (12)	0.0014 (11)
C9	0.079 (3)	0.0372 (17)	0.068 (2)	0.0083 (17)	0.036 (2)	0.0110 (16)
C13	0.0391 (15)	0.0370 (15)	0.0435 (16)	0.0036 (12)	0.0181 (13)	0.0020 (13)
C18	0.0420 (17)	0.0517 (19)	0.0450 (17)	0.0030 (14)	0.0077 (14)	−0.0066 (14)
C17	0.0313 (15)	0.0532 (19)	0.0526 (18)	0.0068 (13)	0.0089 (13)	−0.0008 (15)
C16	0.0340 (14)	0.0406 (16)	0.0400 (15)	0.0088 (12)	0.0114 (12)	0.0033 (12)
C15	0.0378 (15)	0.0434 (16)	0.0380 (15)	0.0091 (13)	0.0061 (12)	0.0005 (13)
C14	0.0324 (14)	0.0427 (16)	0.0504 (17)	0.0090 (13)	0.0099 (13)	−0.0008 (14)
C19	0.0411 (16)	0.0537 (19)	0.0377 (16)	0.0155 (14)	0.0120 (13)	0.0054 (14)
C20	0.0328 (14)	0.0410 (15)	0.0356 (14)	0.0060 (12)	0.0115 (11)	0.0038 (12)
C25	0.0328 (14)	0.0491 (17)	0.0365 (15)	0.0080 (12)	0.0150 (12)	0.0013 (13)
C24	0.0346 (14)	0.0478 (17)	0.0301 (14)	0.0053 (12)	0.0083 (11)	0.0044 (12)
C23	0.0269 (13)	0.0361 (14)	0.0377 (14)	0.0042 (11)	0.0072 (11)	0.0030 (12)
C22	0.0337 (14)	0.0443 (16)	0.0380 (15)	0.0080 (12)	0.0171 (12)	0.0063 (12)
C21	0.0363 (15)	0.0484 (17)	0.0346 (14)	0.0081 (13)	0.0142 (12)	0.0087 (12)
C28	0.0301 (14)	0.0421 (16)	0.0372 (15)	0.0030 (12)	0.0062 (11)	−0.0052 (12)
C29	0.0307 (14)	0.0357 (14)	0.0398 (15)	0.0031 (11)	0.0061 (12)	−0.0026 (12)
C27	0.0310 (13)	0.0328 (14)	0.0386 (15)	0.0027 (11)	0.0055 (11)	0.0010 (11)
C26	0.053 (2)	0.0451 (18)	0.057 (2)	0.0128 (15)	−0.0060 (16)	−0.0141 (15)
C3	0.0376 (15)	0.0418 (15)	0.0281 (13)	−0.0096 (12)	0.0056 (11)	−0.0032 (11)
C4	0.0338 (14)	0.0395 (15)	0.0339 (14)	−0.0078 (12)	0.0066 (11)	−0.0064 (12)
C8	0.0387 (16)	0.0449 (17)	0.0401 (16)	−0.0114 (13)	0.0125 (13)	−0.0083 (13)
C5	0.0366 (15)	0.0427 (16)	0.0409 (16)	−0.0049 (12)	0.0125 (13)	0.0033 (13)

Geometric parameters (Å, º)

Br1—C6	1.896 (3)	C13—C18	1.376 (4)
Zn1—O4^i	1.923 (2)	C13—C14	1.377 (4)
Zn1—O1	1.937 (2)	C18—C17	1.384 (4)
Zn1—N1	2.001 (2)	C18—H18	0.9300
Zn1—N4^ii	2.029 (2)	C17—C16	1.384 (4)
O1—C1	1.272 (3)	C17—H17	0.9300
O5—C19	1.206 (4)	C16—C15	1.388 (4)
O2—C1	1.206 (4)	C16—C19	1.498 (4)
O3—C8	1.224 (4)	C15—C14	1.369 (4)
O4—C8	1.262 (4)	C15—H15	0.9300
O4—Zn1^iii	1.923 (2)	C14—H14	0.9300
N4—C27	1.324 (4)	C19—C20	1.482 (4)
N4—C29	1.376 (4)	C20—C21	1.378 (4)
N4—Zn1^iv	2.029 (2)	C20—C25	1.396 (4)
N1—C10	1.315 (4)	C25—C24	1.382 (4)
N1—C11	1.377 (4)	C25—H25	0.9300
N2—C10	1.345 (4)	C24—C23	1.375 (4)
N2—C12	1.376 (4)	C24—H24	0.9300
N2—C13	1.432 (4)	C23—C22	1.384 (4)
N3—C27	1.351 (4)	C22—C21	1.375 (4)
N3—C28	1.381 (4)	C22—H22	0.9300
N3—C23	1.420 (3)	C21—H21	0.9300
C6—C7	1.370 (4)	C28—C29	1.346 (4)
C6—C5	1.379 (4)	C28—H28	0.9300
C7—C2	1.388 (4)	C29—H29	0.9300
C7—H7	0.9300	C27—C26	1.475 (4)
C2—C3	1.386 (4)	C26—H26A	0.9600
C2—C1	1.505 (4)	C26—H26B	0.9600
C11—C12	1.337 (4)	C26—H26C	0.9600
C11—H11	0.9300	C3—C4	1.378 (4)
C12—H12	0.9300	C3—H3	0.9300
C10—C9	1.479 (4)	C4—C5	1.384 (4)
C9—H9A	0.9600	C4—C8	1.508 (4)
C9—H9B	0.9600	C5—H5	0.9300
C9—H9C	0.9600
O4^i—Zn1—O1	116.87 (12)	C17—C16—C19	123.0 (3)
O4^i—Zn1—N1	100.70 (11)	C15—C16—C19	117.2 (3)
O1—Zn1—N1	119.91 (9)	C14—C15—C16	119.9 (3)
O4^i—Zn1—N4^ii	118.56 (10)	C14—C15—H15	120.0
O1—Zn1—N4^ii	96.63 (9)	C16—C15—H15	120.0
N1—Zn1—N4^ii	104.64 (10)	C15—C14—C13	119.6 (3)
C1—O1—Zn1	118.68 (19)	C15—C14—H14	120.2
C8—O4—Zn1^iii	129.5 (2)	C13—C14—H14	120.2
C27—N4—C29	106.3 (2)	O5—C19—C20	120.6 (3)
C27—N4—Zn1^iv	128.24 (19)	O5—C19—C16	119.7 (3)
C29—N4—Zn1^iv	124.89 (19)	C20—C19—C16	119.7 (3)
C10—N1—C11	107.0 (2)	C21—C20—C25	119.0 (3)
C10—N1—Zn1	129.37 (19)	C21—C20—C19	118.2 (3)
C11—N1—Zn1	123.44 (19)	C25—C20—C19	122.7 (2)
C10—N2—C12	108.1 (2)	C24—C25—C20	120.0 (3)
C10—N2—C13	125.6 (2)	C24—C25—H25	120.0
C12—N2—C13	125.6 (3)	C20—C25—H25	120.0
C27—N3—C28	107.9 (2)	C23—C24—C25	119.8 (3)
C27—N3—C23	126.6 (2)	C23—C24—H24	120.1
C28—N3—C23	125.5 (2)	C25—C24—H24	120.1
C7—C6—C5	122.0 (3)	C24—C23—C22	120.7 (3)
C7—C6—Br1	118.7 (2)	C24—C23—N3	120.3 (2)
C5—C6—Br1	119.3 (2)	C22—C23—N3	119.0 (2)
C6—C7—C2	119.1 (3)	C21—C22—C23	119.1 (3)
C6—C7—H7	120.4	C21—C22—H22	120.4
C2—C7—H7	120.4	C23—C22—H22	120.4
C3—C2—C7	119.1 (3)	C22—C21—C20	121.2 (3)
C3—C2—C1	120.3 (3)	C22—C21—H21	119.4
C7—C2—C1	120.6 (2)	C20—C21—H21	119.4
O2—C1—O1	124.3 (3)	C29—C28—N3	105.7 (3)
O2—C1—C2	120.2 (3)	C29—C28—H28	127.1
O1—C1—C2	115.6 (3)	N3—C28—H28	127.1
C12—C11—N1	109.2 (3)	C28—C29—N4	110.0 (3)
C12—C11—H11	125.4	C28—C29—H29	125.0
N1—C11—H11	125.4	N4—C29—H29	125.0
C11—C12—N2	106.1 (3)	N4—C27—N3	110.0 (2)
C11—C12—H12	126.9	N4—C27—C26	124.5 (3)
N2—C12—H12	126.9	N3—C27—C26	125.3 (3)
N1—C10—N2	109.5 (2)	C27—C26—H26A	109.5
N1—C10—C9	126.6 (3)	C27—C26—H26B	109.5
N2—C10—C9	123.9 (3)	H26A—C26—H26B	109.5
C10—C9—H9A	109.5	C27—C26—H26C	109.5
C10—C9—H9B	109.5	H26A—C26—H26C	109.5
H9A—C9—H9B	109.5	H26B—C26—H26C	109.5
C10—C9—H9C	109.5	C4—C3—C2	121.4 (3)
H9A—C9—H9C	109.5	C4—C3—H3	119.3
H9B—C9—H9C	109.5	C2—C3—H3	119.3
C18—C13—C14	121.5 (3)	C3—C4—C5	119.3 (3)
C18—C13—N2	120.5 (3)	C3—C4—C8	120.3 (3)
C14—C13—N2	118.0 (3)	C5—C4—C8	120.4 (3)
C13—C18—C17	118.7 (3)	O3—C8—O4	125.5 (3)
C13—C18—H18	120.6	O3—C8—C4	120.0 (3)
C17—C18—H18	120.6	O4—C8—C4	114.4 (3)
C18—C17—C16	120.3 (3)	C6—C5—C4	119.1 (3)
C18—C17—H17	119.9	C6—C5—H5	120.4
C16—C17—H17	119.9	C4—C5—H5	120.4
C17—C16—C15	119.8 (3)
C5—C6—C7—C2	−0.1 (5)	O5—C19—C20—C25	152.2 (4)
Br1—C6—C7—C2	179.0 (2)	C16—C19—C20—C25	−26.2 (5)
C6—C7—C2—C3	−0.7 (4)	C21—C20—C25—C24	−3.0 (5)
C6—C7—C2—C1	−178.0 (3)	C19—C20—C25—C24	179.9 (3)
Zn1—O1—C1—O2	−13.0 (5)	C20—C25—C24—C23	−1.8 (5)
Zn1—O1—C1—C2	166.58 (19)	C25—C24—C23—C22	5.2 (5)
C3—C2—C1—O2	6.8 (5)	C25—C24—C23—N3	−176.6 (3)
C7—C2—C1—O2	−175.9 (3)	C27—N3—C23—C24	45.0 (4)
C3—C2—C1—O1	−172.8 (3)	C28—N3—C23—C24	−135.4 (3)
C7—C2—C1—O1	4.5 (4)	C27—N3—C23—C22	−136.8 (3)
C10—N1—C11—C12	1.1 (4)	C28—N3—C23—C22	42.8 (4)
Zn1—N1—C11—C12	−174.4 (2)	C24—C23—C22—C21	−3.7 (5)
N1—C11—C12—N2	−1.1 (4)	N3—C23—C22—C21	178.1 (3)
C10—N2—C12—C11	0.7 (4)	C23—C22—C21—C20	−1.3 (5)
C13—N2—C12—C11	−169.7 (3)	C25—C20—C21—C22	4.5 (5)
C11—N1—C10—N2	−0.6 (3)	C19—C20—C21—C22	−178.2 (3)
Zn1—N1—C10—N2	174.5 (2)	C27—N3—C28—C29	−1.3 (3)
C11—N1—C10—C9	178.6 (3)	C23—N3—C28—C29	179.1 (3)
Zn1—N1—C10—C9	−6.3 (5)	N3—C28—C29—N4	0.6 (3)
C12—N2—C10—N1	0.0 (4)	C27—N4—C29—C28	0.3 (3)
C13—N2—C10—N1	170.4 (3)	Zn1^iv—N4—C29—C28	−171.8 (2)
C12—N2—C10—C9	−179.3 (3)	C29—N4—C27—N3	−1.1 (3)
C13—N2—C10—C9	−8.9 (5)	Zn1^iv—N4—C27—N3	170.65 (18)
C10—N2—C13—C18	90.3 (4)	C29—N4—C27—C26	174.2 (3)
C12—N2—C13—C18	−101.0 (4)	Zn1^iv—N4—C27—C26	−14.0 (4)
C10—N2—C13—C14	−89.1 (4)	C28—N3—C27—N4	1.5 (3)
C12—N2—C13—C14	79.7 (4)	C23—N3—C27—N4	−178.8 (2)
C14—C13—C18—C17	3.2 (5)	C28—N3—C27—C26	−173.8 (3)
N2—C13—C18—C17	−176.2 (3)	C23—N3—C27—C26	5.9 (5)
C13—C18—C17—C16	−0.6 (5)	C7—C2—C3—C4	0.8 (4)
C18—C17—C16—C15	−2.9 (5)	C1—C2—C3—C4	178.1 (3)
C18—C17—C16—C19	176.3 (3)	C2—C3—C4—C5	0.0 (5)
C17—C16—C15—C14	4.0 (5)	C2—C3—C4—C8	−179.6 (3)
C19—C16—C15—C14	−175.3 (3)	Zn1^iii—O4—C8—O3	−3.7 (6)
C16—C15—C14—C13	−1.5 (5)	Zn1^iii—O4—C8—C4	177.2 (2)
C18—C13—C14—C15	−2.1 (5)	C3—C4—C8—O3	6.8 (5)
N2—C13—C14—C15	177.2 (3)	C5—C4—C8—O3	−172.7 (3)
C17—C16—C19—O5	153.0 (4)	C3—C4—C8—O4	−173.9 (3)
C15—C16—C19—O5	−27.8 (5)	C5—C4—C8—O4	6.5 (4)
C17—C16—C19—C20	−28.7 (5)	C7—C6—C5—C4	0.9 (5)
C15—C16—C19—C20	150.5 (3)	Br1—C6—C5—C4	−178.2 (2)
O5—C19—C20—C21	−25.0 (5)	C3—C4—C5—C6	−0.8 (4)
C16—C19—C20—C21	156.6 (3)	C8—C4—C5—C6	178.8 (3)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C9—H9C···O5^v	0.96	2.49	3.427 (5)	164
C28—H28···O3^vi	0.93	2.36	3.248 (4)	159

Symmetry codes: (v) x, −y+1/2, z−1/2; (vi) −x+1, −y+1, −z+1.