Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536802002660/cv6089sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536802002660/cv6089Isup2.hkl |
CCDC reference: 182621
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.002 Å
- R factor = 0.048
- wR factor = 0.157
- Data-to-parameter ratio = 18.8
checkCIF results
No syntax errors found ADDSYM reports no extra symmetry
Alert Level B:
PLAT_030 Alert B Refined Extinction parameter within range .... 1.00 Sigma
Alert Level C:
ABSMU_01 Alert C The ratio of given/expected absorption coefficient lies outside the range 0.99 <> 1.01 Calculated value of mu = 0.111 Value of mu given = 0.110 REFLT_03 From the CIF: _diffrn_reflns_theta_max 30.00 From the CIF: _reflns_number_total 3958 TEST2: Reflns within _diffrn_reflns_theta_max Count of symmetry unique reflns 4185 Completeness (_total/calc) 94.58% Alert C: < 95% complete
0 Alert Level A = Potentially serious problem
1 Alert Level B = Potential problem
2 Alert Level C = Please check
The plant material (all parts, 13 kg) was collected from Quetta, Pakistan, in July 1999, dried under shade for a period of two weeks, and soaked in hexane (12 l × 2) and methanol (12 l × 2) for 10 d in each solvent. Solvents were evaporated through vacuum distillation. The crude methanolic extract (217 g) was partitioned between water and ethyl acetate. The ethyl acetate layer was condensed (167 g) and subjected to column chromatography using hexane, hexane–ethyl acetate, ethyl acetate and ethyl acetate–methanol as mobile phases. Elution with 20% ethyl acetate in hexane afforded yellow crystals (11.6 mg) suitable for XRD analysis.
The space group was determined uniquely from the systematic absences. The H atoms were located from difference Fourier synthesis and were included in the refinement at geometrically idealized positions, with C—H 0.93–0.96 Å and O—H 0.82 Å, utilizing riding models.
Data collection: COLLECT (Hooft, 1998); cell refinement: HKL DENZO (Otwinowski & Minor, 1997); data reduction: SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SAPI91 (Fan, 1991); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: TEXSAN (Molecular Structure Corporation, 1994); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).
C17H14O6 | Dx = 1.455 Mg m−3 |
Mr = 314.28 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, Pbca | Cell parameters from 3674 reflections |
a = 8.3669 (2) Å | θ = 1.0–30.0° |
b = 13.5769 (4) Å | µ = 0.11 mm−1 |
c = 25.2554 (9) Å | T = 293 K |
V = 2868.93 (15) Å3 | Prismatic, yellow |
Z = 8 | 0.25 × 0.25 × 0.13 mm |
F(000) = 1312 |
Nonius KappaCCD diffractometer | 3958 independent reflections |
Radiation source: fine-focus sealed tube | 2594 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.036 |
ω–2ϕ scans | θmax = 30.0°, θmin = 3.2° |
Absorption correction: multi-scan (SORTAV: Blessing, 1995, 1997) | h = −11→11 |
Tmin = 0.973, Tmax = 0.986 | k = −18→18 |
6714 measured reflections | l = −35→35 |
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)] = 0.048 | H-atom parameters constrained |
wR(F2) = 0.157 | w = 1/[σ2(Fo2) + (0.092P)2 + 0.124P] where P = (Fo2 + 2Fc2)/3 |
S = 0.98 | (Δ/σ)max < 0.001 |
3958 reflections | Δρmax = 0.22 e Å−3 |
211 parameters | Δρmin = −0.19 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.004 (4) |
C17H14O6 | V = 2868.93 (15) Å3 |
Mr = 314.28 | Z = 8 |
Orthorhombic, Pbca | Mo Kα radiation |
a = 8.3669 (2) Å | µ = 0.11 mm−1 |
b = 13.5769 (4) Å | T = 293 K |
c = 25.2554 (9) Å | 0.25 × 0.25 × 0.13 mm |
Nonius KappaCCD diffractometer | 3958 independent reflections |
Absorption correction: multi-scan (SORTAV: Blessing, 1995, 1997) | 2594 reflections with I > 2σ(I) |
Tmin = 0.973, Tmax = 0.986 | Rint = 0.036 |
6714 measured reflections |
R[F2 > 2σ(F2)] = 0.048 | 0 restraints |
wR(F2) = 0.157 | H-atom parameters constrained |
S = 0.98 | Δρmax = 0.22 e Å−3 |
3958 reflections | Δρmin = −0.19 e Å−3 |
211 parameters |
x | y | z | Uiso*/Ueq | ||
O1 | 0.80664 (14) | 0.24686 (7) | 0.80247 (4) | 0.0381 (3) | |
O2 | 1.02299 (16) | 0.51658 (8) | 0.80368 (5) | 0.0536 (4) | |
O3 | 0.99288 (17) | 0.52501 (8) | 0.70219 (5) | 0.0516 (3) | |
H3 | 1.0179 | 0.5432 | 0.7320 | 0.077* | |
O4 | 0.88775 (12) | 0.43326 (7) | 0.61005 (4) | 0.0371 (3) | |
O5 | 0.77847 (13) | 0.25240 (7) | 0.61361 (4) | 0.0387 (3) | |
C2 | 0.84898 (17) | 0.29054 (11) | 0.84907 (6) | 0.0349 (3) | |
C3 | 0.9234 (2) | 0.37910 (11) | 0.85047 (6) | 0.0400 (4) | |
H3A | 0.9534 | 0.4052 | 0.8830 | 0.048* | |
C4 | 0.95727 (19) | 0.43342 (11) | 0.80347 (6) | 0.0382 (4) | |
C5 | 0.92861 (18) | 0.43392 (10) | 0.70475 (6) | 0.0356 (4) | |
C6 | 0.88195 (17) | 0.38706 (10) | 0.65878 (6) | 0.0336 (3) | |
C7 | 0.81601 (16) | 0.29160 (10) | 0.66133 (6) | 0.0320 (3) | |
C8 | 0.79119 (18) | 0.24486 (11) | 0.70964 (6) | 0.0339 (3) | |
H8 | 0.7458 | 0.1824 | 0.7113 | 0.041* | |
C9 | 0.83633 (18) | 0.29435 (10) | 0.75520 (6) | 0.0331 (3) | |
C10 | 0.90838 (18) | 0.38715 (10) | 0.75431 (6) | 0.0342 (3) | |
C11 | 1.04456 (19) | 0.45254 (14) | 0.58946 (8) | 0.0514 (5) | |
H11A | 1.0356 | 0.4849 | 0.5558 | 0.077* | |
H11B | 1.1010 | 0.3915 | 0.5852 | 0.077* | |
H11C | 1.1019 | 0.4941 | 0.6137 | 0.077* | |
C12 | 0.72652 (19) | 0.15138 (11) | 0.61253 (6) | 0.0402 (4) | |
H12A | 0.7038 | 0.1324 | 0.5767 | 0.060* | |
H12B | 0.6318 | 0.1444 | 0.6336 | 0.060* | |
H12C | 0.8093 | 0.1100 | 0.6265 | 0.060* | |
O4' | 0.66934 (13) | 0.07247 (9) | 1.02896 (4) | 0.0458 (3) | |
H4' | 0.7316 | 0.0822 | 1.0535 | 0.069* | |
C1' | 0.80245 (17) | 0.23266 (11) | 0.89568 (6) | 0.0342 (3) | |
C2' | 0.87905 (19) | 0.24867 (12) | 0.94417 (6) | 0.0406 (4) | |
H2' | 0.9605 | 0.2951 | 0.9463 | 0.049* | |
C3' | 0.83574 (18) | 0.19664 (12) | 0.98898 (6) | 0.0414 (4) | |
H3' | 0.8881 | 0.2081 | 1.0209 | 0.050* | |
C4' | 0.71426 (17) | 0.12738 (10) | 0.98637 (6) | 0.0343 (3) | |
C5' | 0.63504 (17) | 0.11167 (12) | 0.93868 (6) | 0.0379 (4) | |
H5' | 0.5518 | 0.0664 | 0.9370 | 0.045* | |
C6' | 0.67942 (17) | 0.16312 (11) | 0.89360 (6) | 0.0370 (4) | |
H6' | 0.6270 | 0.1513 | 0.8618 | 0.044* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0562 (6) | 0.0354 (6) | 0.0227 (5) | −0.0062 (5) | −0.0028 (4) | 0.0002 (4) |
O2 | 0.0764 (9) | 0.0399 (7) | 0.0446 (7) | −0.0172 (6) | −0.0116 (6) | −0.0043 (5) |
O3 | 0.0762 (8) | 0.0345 (6) | 0.0442 (7) | −0.0169 (6) | −0.0165 (6) | 0.0049 (5) |
O4 | 0.0415 (6) | 0.0382 (6) | 0.0315 (6) | −0.0045 (4) | −0.0033 (4) | 0.0112 (5) |
O5 | 0.0577 (6) | 0.0348 (6) | 0.0237 (5) | −0.0076 (5) | −0.0035 (5) | 0.0001 (4) |
C2 | 0.0392 (7) | 0.0396 (8) | 0.0261 (7) | 0.0035 (6) | −0.0032 (6) | −0.0034 (6) |
C3 | 0.0519 (9) | 0.0403 (9) | 0.0277 (8) | −0.0021 (7) | −0.0043 (7) | −0.0060 (6) |
C4 | 0.0450 (8) | 0.0350 (8) | 0.0347 (8) | 0.0005 (6) | −0.0062 (6) | −0.0045 (6) |
C5 | 0.0436 (8) | 0.0281 (7) | 0.0350 (8) | −0.0019 (6) | −0.0064 (6) | 0.0040 (6) |
C6 | 0.0392 (7) | 0.0318 (7) | 0.0298 (8) | −0.0009 (6) | −0.0046 (6) | 0.0061 (6) |
C7 | 0.0367 (7) | 0.0324 (7) | 0.0269 (7) | 0.0001 (6) | −0.0029 (6) | 0.0001 (6) |
C8 | 0.0462 (8) | 0.0286 (7) | 0.0269 (7) | −0.0048 (6) | −0.0030 (6) | 0.0007 (6) |
C9 | 0.0409 (8) | 0.0330 (7) | 0.0253 (7) | 0.0008 (6) | −0.0020 (6) | 0.0021 (6) |
C10 | 0.0427 (8) | 0.0297 (7) | 0.0301 (8) | 0.0005 (6) | −0.0063 (6) | −0.0001 (6) |
C11 | 0.0457 (9) | 0.0589 (11) | 0.0495 (11) | −0.0028 (7) | 0.0063 (8) | 0.0118 (9) |
C12 | 0.0522 (9) | 0.0361 (8) | 0.0323 (8) | −0.0060 (6) | −0.0048 (7) | −0.0022 (6) |
O4' | 0.0489 (6) | 0.0585 (7) | 0.0301 (6) | −0.0075 (5) | −0.0027 (5) | 0.0058 (5) |
C1' | 0.0391 (7) | 0.0384 (8) | 0.0250 (7) | 0.0049 (6) | −0.0006 (6) | −0.0023 (6) |
C2' | 0.0454 (8) | 0.0497 (9) | 0.0267 (8) | −0.0089 (7) | −0.0035 (6) | −0.0024 (7) |
C3' | 0.0467 (8) | 0.0517 (9) | 0.0258 (8) | −0.0036 (7) | −0.0041 (6) | −0.0036 (7) |
C4' | 0.0370 (7) | 0.0392 (8) | 0.0267 (7) | 0.0047 (6) | 0.0020 (6) | −0.0012 (6) |
C5' | 0.0384 (8) | 0.0415 (8) | 0.0338 (8) | −0.0014 (6) | −0.0032 (6) | −0.0018 (7) |
C6' | 0.0406 (8) | 0.0417 (8) | 0.0288 (8) | 0.0012 (6) | −0.0064 (6) | −0.0036 (6) |
O1—C2 | 1.3645 (16) | C9—C10 | 1.397 (2) |
O1—C9 | 1.3794 (16) | C11—H11A | 0.9600 |
O2—C4 | 1.2559 (19) | C11—H11B | 0.9600 |
O3—C5 | 1.3502 (17) | C11—H11C | 0.9600 |
O3—H3 | 0.8200 | C12—H12A | 0.9600 |
O4—C6 | 1.3821 (17) | C12—H12B | 0.9600 |
O4—C11 | 1.4353 (19) | C12—H12C | 0.9600 |
O5—C7 | 1.3544 (16) | O4'—C4' | 1.3617 (17) |
O5—C12 | 1.4390 (17) | O4'—H4' | 0.8200 |
C2—C3 | 1.355 (2) | C1'—C6' | 1.398 (2) |
C2—C1' | 1.468 (2) | C1'—C2' | 1.399 (2) |
C3—C4 | 1.426 (2) | C2'—C3' | 1.383 (2) |
C3—H3A | 0.9300 | C2'—H2' | 0.9300 |
C4—C10 | 1.450 (2) | C3'—C4' | 1.386 (2) |
C5—C6 | 1.380 (2) | C3'—H3' | 0.9300 |
C5—C10 | 1.414 (2) | C4'—C5' | 1.391 (2) |
C6—C7 | 1.410 (2) | C5'—C6' | 1.386 (2) |
C7—C8 | 1.3908 (19) | C5'—H5' | 0.9300 |
C8—C9 | 1.3850 (19) | C6'—H6' | 0.9300 |
C8—H8 | 0.9300 | ||
C2—O1—C9 | 119.77 (11) | O4—C11—H11A | 109.5 |
C5—O3—H3 | 109.5 | O4—C11—H11B | 109.5 |
C6—O4—C11 | 115.94 (12) | H11A—C11—H11B | 109.5 |
C7—O5—C12 | 117.49 (12) | O4—C11—H11C | 109.5 |
C3—C2—O1 | 121.85 (13) | H11A—C11—H11C | 109.5 |
C3—C2—C1' | 125.18 (14) | H11B—C11—H11C | 109.5 |
O1—C2—C1' | 112.96 (13) | O5—C12—H12A | 109.5 |
C2—C3—C4 | 121.91 (14) | O5—C12—H12B | 109.5 |
C2—C3—H3A | 119.0 | H12A—C12—H12B | 109.5 |
C4—C3—H3A | 119.0 | O5—C12—H12C | 109.5 |
O2—C4—C3 | 123.25 (14) | H12A—C12—H12C | 109.5 |
O2—C4—C10 | 121.10 (14) | H12B—C12—H12C | 109.5 |
C3—C4—C10 | 115.64 (13) | C4'—O4'—H4' | 109.5 |
O3—C5—C6 | 119.64 (13) | C6'—C1'—C2' | 118.38 (14) |
O3—C5—C10 | 120.09 (13) | C6'—C1'—C2 | 121.78 (14) |
C6—C5—C10 | 120.26 (13) | C2'—C1'—C2 | 119.82 (14) |
C5—C6—O4 | 122.00 (12) | C3'—C2'—C1' | 121.13 (14) |
C5—C6—C7 | 119.72 (13) | C3'—C2'—H2' | 119.4 |
O4—C6—C7 | 118.14 (12) | C1'—C2'—H2' | 119.4 |
O5—C7—C8 | 124.52 (13) | C2'—C3'—C4' | 119.98 (14) |
O5—C7—C6 | 114.28 (12) | C2'—C3'—H3' | 120.0 |
C8—C7—C6 | 121.19 (13) | C4'—C3'—H3' | 120.0 |
C9—C8—C7 | 117.83 (13) | O4'—C4'—C3' | 122.42 (14) |
C9—C8—H8 | 121.1 | O4'—C4'—C5' | 117.93 (13) |
C7—C8—H8 | 121.1 | C3'—C4'—C5' | 119.65 (14) |
O1—C9—C8 | 116.31 (12) | C6'—C5'—C4' | 120.40 (14) |
O1—C9—C10 | 120.88 (12) | C6'—C5'—H5' | 119.8 |
C8—C9—C10 | 122.81 (13) | C4'—C5'—H5' | 119.8 |
C9—C10—C5 | 118.10 (13) | C5'—C6'—C1' | 120.44 (14) |
C9—C10—C4 | 119.91 (13) | C5'—C6'—H6' | 119.8 |
C5—C10—C4 | 121.99 (13) | C1'—C6'—H6' | 119.8 |
C9—O1—C2—C3 | −1.6 (2) | C8—C9—C10—C5 | 3.1 (2) |
C9—O1—C2—C1' | 177.30 (11) | O1—C9—C10—C4 | 1.8 (2) |
O1—C2—C3—C4 | 2.1 (2) | C8—C9—C10—C4 | −178.03 (14) |
C1'—C2—C3—C4 | −176.59 (14) | O3—C5—C10—C9 | 177.83 (14) |
C2—C3—C4—O2 | 178.40 (16) | C6—C5—C10—C9 | −1.8 (2) |
C2—C3—C4—C10 | −0.7 (2) | O3—C5—C10—C4 | −1.0 (2) |
O3—C5—C6—O4 | −4.9 (2) | C6—C5—C10—C4 | 179.37 (13) |
C10—C5—C6—O4 | 174.69 (13) | O2—C4—C10—C9 | 179.64 (15) |
O3—C5—C6—C7 | 179.48 (14) | C3—C4—C10—C9 | −1.3 (2) |
C10—C5—C6—C7 | −0.9 (2) | O2—C4—C10—C5 | −1.5 (2) |
C11—O4—C6—C5 | 69.29 (19) | C3—C4—C10—C5 | 177.57 (13) |
C11—O4—C6—C7 | −115.04 (15) | C3—C2—C1'—C6' | 156.21 (16) |
C12—O5—C7—C8 | −7.4 (2) | O1—C2—C1'—C6' | −22.6 (2) |
C12—O5—C7—C6 | 173.57 (13) | C3—C2—C1'—C2' | −21.9 (2) |
C5—C6—C7—O5 | −178.47 (13) | O1—C2—C1'—C2' | 159.30 (13) |
O4—C6—C7—O5 | 5.75 (19) | C6'—C1'—C2'—C3' | 0.6 (2) |
C5—C6—C7—C8 | 2.5 (2) | C2—C1'—C2'—C3' | 178.76 (14) |
O4—C6—C7—C8 | −173.27 (13) | C1'—C2'—C3'—C4' | −0.2 (2) |
O5—C7—C8—C9 | 179.81 (13) | C2'—C3'—C4'—O4' | 178.44 (14) |
C6—C7—C8—C9 | −1.3 (2) | C2'—C3'—C4'—C5' | −0.9 (2) |
C2—O1—C9—C8 | 179.43 (12) | O4'—C4'—C5'—C6' | −177.83 (13) |
C2—O1—C9—C10 | −0.5 (2) | C3'—C4'—C5'—C6' | 1.5 (2) |
C7—C8—C9—O1 | 178.54 (12) | C4'—C5'—C6'—C1' | −1.1 (2) |
C7—C8—C9—C10 | −1.6 (2) | C2'—C1'—C6'—C5' | 0.1 (2) |
O1—C9—C10—C5 | −177.04 (13) | C2—C1'—C6'—C5' | −178.08 (13) |
D—H···A | D—H | H···A | D···A | D—H···A |
O4′—H4′···O4i | 0.82 | 1.95 | 2.7459 (15) | 164 |
O3—H3···O2 | 0.82 | 1.85 | 2.5780 (16) | 148 |
Symmetry code: (i) x, −y+1/2, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C17H14O6 |
Mr | 314.28 |
Crystal system, space group | Orthorhombic, Pbca |
Temperature (K) | 293 |
a, b, c (Å) | 8.3669 (2), 13.5769 (4), 25.2554 (9) |
V (Å3) | 2868.93 (15) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.25 × 0.25 × 0.13 |
Data collection | |
Diffractometer | Nonius KappaCCD diffractometer |
Absorption correction | Multi-scan (SORTAV: Blessing, 1995, 1997) |
Tmin, Tmax | 0.973, 0.986 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6714, 3958, 2594 |
Rint | 0.036 |
(sin θ/λ)max (Å−1) | 0.703 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.048, 0.157, 0.98 |
No. of reflections | 3958 |
No. of parameters | 211 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.22, −0.19 |
Computer programs: COLLECT (Hooft, 1998), HKL DENZO (Otwinowski & Minor, 1997), SCALEPACK (Otwinowski & Minor, 1997), SAPI91 (Fan, 1991), SHELXL97 (Sheldrick, 1997), TEXSAN (Molecular Structure Corporation, 1994).
O1—C2 | 1.3645 (16) | O4—C11 | 1.4353 (19) |
O1—C9 | 1.3794 (16) | O5—C7 | 1.3544 (16) |
O2—C4 | 1.2559 (19) | O5—C12 | 1.4390 (17) |
O3—C5 | 1.3502 (17) | O4'—C4' | 1.3617 (17) |
O4—C6 | 1.3821 (17) | ||
C2—O1—C9 | 119.77 (11) | C7—O5—C12 | 117.49 (12) |
C6—O4—C11 | 115.94 (12) |
D—H···A | D—H | H···A | D···A | D—H···A |
O4'—H4'···O4i | 0.82 | 1.95 | 2.7459 (15) | 164 |
O3—H3···O2 | 0.82 | 1.85 | 2.5780 (16) | 148 |
Symmetry code: (i) x, −y+1/2, z+1/2. |
Salvia is the largest genus of the plant family Lamiaceae (previously known as Labiateae) comprising aromatic and ornamental herbs and shrubs distributed in the temperate and tropical regions. Species of Salvia are known to contain terpenes and steroids (Pereda-Miranda et al., 1986). We have isolated 5,4'-dihydroxy-6,7-dimethoxyflavone (cirsimaritin), (I), from Salvia nubicola Wall. ex Sweet; it had been previously isolated from Centaurea scoparia (Youssef & Frahm, 1995). The crystal structure of a very closely related flavone, eupatorin, has been reported from our laboratory (Parvez et al., 2001). The inhibitory effects of (I) on both bovine-LAR and rabbit platellet aggregation have been reported (Okada et al., 1995). The crystal structure of (I) has been determined by X-ray crystallographic method which is reported in this paper.
The structure of (I) is presented in Fig. 1. The benzopyran ring is planar within 0.0314 (11) Å. The mean plane of phenyl ring C1'-C6' is inclined at 23.30 (6)° to the mean plane of the benzopyran ring. The carbonyl O2 and hydroxyl O3 lie slightly above [0.044 (2) Å] and below [0.066 (2) Å] the plane of the benzopyran ring. The methoxy groups O4/C11 and O5/C12 are oriented at 65.90 (11) and 8.39 (10)°, respectively, from the benzopyran ring. The molecular dimensions in (I) lie within expected values (Orpen et al., 1994) for the corresponding bond distances and angles and agree well with those reported for a dozen or so similar compounds contained in the October 2001 updates of the Cambridge Structural Database (Allen & Kennard, 1993). The mean bond distances are: O—Csp3 1.4372 (18), O—Csp2 1.365 (12), Csp2—Csp2 1.448 (17), C—Caromatic 1.393 (10) and C═O 1.2559 (19) Å.
The structure is stabilized by strong intramolecular and intermolecular hydrogen bonds. The hydroxyl H atom is intramolecularly bonded with the carbonyl O atom [H3···O2 1.85, O3···O2 2.5780 (16) Å and O3—H3···O2 148°]. The intermolecular hydrogen bond between the 6-methoxy O4 and the 4'-hydroxyl H atoms [H4'···O4 1.95, O4'···O4 2.7459 (15) Å and O4'—H4'···O4 164°] results in a chain structure along the c axis; details of the hydrogen-bonding geometry have been provided in Table 2 and are presented in Fig. 2.