Semisynthetic roxburghin tetramethyl ether
Saez, Alex; Ramirez de Arellano, Carmen; El Aouad, Noureddine; Rodriguez, Silvia; Otalvaro, Felipe; Cortes, Diego; Saez, Jairo; Acta Crystallographica Section E 64 (2008) o1305–; doi:10.1107/S1600536808018266

data_2218681
_publ_section_title
;
 Semisynthetic roxburghin tetramethyl ether
;
_journal_coeditor_code           FB2091
_journal_issue                   7
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1305
_journal_paper_doi               10.1107/S1600536808018266
_journal_volume                  64
_journal_year                    2008
_chemical_formula_iupac          'C18 H20 O4'
_chemical_formula_moiety         'C18 H20 O4'
_chemical_formula_sum            'C18 H20 O4'
_chemical_formula_weight         300.34
_chemical_name_common            'roxburghin tetramethyl ether'
_chemical_name_systematic
;
(<i>E</i>)-2,3',4,5-tetramethoxystilbene
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                73.400(2)
_cell_angle_beta                 75.479(3)
_cell_angle_gamma                70.335(2)
_cell_formula_units_Z            2
_cell_length_a                   7.9633(4)
_cell_length_b                   9.2454(5)
_cell_length_c                   11.6194(5)
_cell_measurement_reflns_used    46078
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      30.034
_cell_measurement_theta_min      0.998
_cell_volume                     760.59(7)
_computing_cell_refinement       'SCALEPACK (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Nonius, 1998)'
_computing_data_reduction        'SCALEPACK (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'SHELXTL/PC (Sheldrick, 2008)'
_computing_publication_material  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      150(2)
_diffrn_detector_area_resol_mean 9
_diffrn_measured_fraction_theta_full 0.988
_diffrn_measured_fraction_theta_max 0.988
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0254
_diffrn_reflns_av_sigmaI/netI    0.0445
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            8260
_diffrn_reflns_theta_full        30.03
_diffrn_reflns_theta_max         30.03
_diffrn_reflns_theta_min         2.69
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.092
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.311
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             320
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.292
_refine_diff_density_min         -0.231
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.982
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_constraints    76
_refine_ls_number_parameters     203
_refine_ls_number_reflns         4391
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.982
_refine_ls_R_factor_all          0.0820
_refine_ls_R_factor_gt           0.0472
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0789P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1216
_refine_ls_wR_factor_ref         0.1360
_reflns_number_gt                2785
_reflns_number_total             4391
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            fb2091.cif
_cod_data_source_block           I
_cod_database_code               2218681
_cod_database_fobs_code          2218681