Crystal structure of 6-hydroxy-2',3',4'-trimethoxyflavone, C18H16O6

CigHieOe, monoclinic, P12i/nl (No. 14), a = 14.684(2) Ä, b = 13.251(2) Ä, c = 7.982(1) Ä, β = 92.87(1)°, V= 1551.2 Ä, Z = 4, Rgt(F) = 0.057, R^F) = 0.082, T= 293 K. Source of material According to [1], Discussion The two diortho-substituted methoxyl groups are approximately orthogonal to the phenyl ring and point in opposite directions. The phenolic Η atom was not located but its presence was inferred from the 0 4 0 6 distance 2.749(2) A. Crystal: colourless, prismatic, size 0.20 χ 0.30 χ 0.35 mm Wavelength: Cu Ka radiation (1.54184 Ä) μ : 8.90 cm" 1 Diffractometer, scan mode: Enraf-Nonius CAD4, ω/20 29max: 140° WlWjmeasured, N(hkl)unique: 2782,2782 Criterion for 70bs, N(hkl)gc. /obs > 3 a(/obs), 2 6 1 8 N(param)KTmed· 217 Programs: SHELXS-84 [2], SHELXL-93 [3] Table 2. Atomic coordinates and displacement parameters (in A ). Atom Site X y ζ ßiso H(3) Ae 1.1268 0.1611 0.4332 7.71 H(5) Ae 0.9502 0.4731 0.4393 7.56 H(7) Ae 0.7201 0.3997 0.1147 7.77 H(8) Ae 0.7771 0.2277 0.0800 7.71 H(2'1A) 4e 1.2196 0.0832 0.0919 10.02 H(2'1B) Ae 1.3062 0.0912 0.2535 10.02 H(2'1C) Ae 1.2775 -0.0270 0.1627 10.02 H(3'1A) Ae 1.2011 -0.2314 0.4897 10.26 H(3'1B) Ae 1.3113 -0.2187 0.4122 10.26 H(3'1C) Ae 1.2517 -0.1107 0.4768 10.26 H(4'1A) Ae 0.9726 -0.3265 -0.0143 8.95 H(4'1B) Ae 1.0209 -0.4292 0.1002 8.95 H(4'1C) Ae 0.9390 -0.3514 0.1913 8.95 H(5') Ae 0.9025 -0.1918 0.1344 7.77 H(6') Ae 0.8825 -0.0104 0.1863 7.62 Table 3. Atomic coordinates and displacement parameters (in Ä). Atom Site X y ζ Un U22 t/33 Un Un t/23 C(2) Ae 1.0074(1) 0.1254(1) 0.2882(2) 0.038(1) 0.043(1) 0.040(1) 0.002(1) -0.003(1) -0.003(1) C(3) Ae 1.0615(1) 0.1891(1) 0.3819(3) 0.043(1) 0.046(1) 0.051(1) 0.005(1) -0.011(1) -0.008(1) C(4) Ae 1.0362(1) 0.2912(1) 0.4149(3) 0.040(1) 0.045(1) 0.047(1) 0.001(1) -0.008(1) -0.007(1) 0(4) Ae 1.0852(1) 0.3500(1) 0.5001(2) 0.051(1) 0.052(1) 0.077(1) 0.005(1) -0.025(1) -0.022(1) C(5) Ae 0.9131(1) 0.4195(1) 0.3596(3) 0.040(1) 0.043(1) 0.052(1) 0.001(1) -0.009(1) -0.005(1) C(6) Ae 0.8314(1) 0.4470(1) 0.2813(2) 0.039(1) 0.043(1) 0.047(1) 0.003(1) -0.003(1) 0.000(1) 0(6) Ae 0.7942(1) 0.5407(1) 0.2978(2) 0.047(1) 0.043(1) 0.070(1) 0.007(1) -0.012(1) -0.006(1) C(7) Ae 0.7826(1) 0.3775(2) 0.1786(3) 0.039(1) 0.050(1) 0.053(1) 0.003(1) -0.010(1) -0.001(1) C(8) Ae 0.8154(1) 0.2811(2) 0.1576(3) 0.039(1) 0.049(1) 0.052(1) 0.000(1) -0.009(1) -0.005(1) C(9) Ae 0.8979(1) 0.2541(1) 0.2390(2) 0.037(1) 0.040(1) 0.042(1) 0.000(1) -0.002(1) -0.003(1) C(10) Ae 0.9481(1) 0.3222(1) 0.3379(2) 0.037(1) 0.042(1) 0.040(1) 0.000(1) -0.004(1) -0.002(1) C(l ' ) Ae 1.0233(1) 0.0180(1) 0.2544(2) 0.038(1) 0.042(1) 0.042(1) -0.001(1) -0.002(1) -0.004(1) C(2') Ae 1.1103(1) -0.0267(1) 0.2722(2) 0.038(1) 0.043(1) 0.042(1) -0.002(1) -0.004(1) -0.007(1) 0(2 ' ) Ae 1.1848(1) 0.0302(1) 0.3217(2) 0.037(1) 0.051(1) 0.065(1) -0.003(1) -0.005(1) -0.016(1) Correspondence author (e-mail: wallet@iut-chimie.u-3mrs.fr) 466 6-Hydroxy-2',3',4'-trimethoxyflavone