1,4,5,8-Tetramethoxyanthracene
Springer, J. W.; Moore, T. A.; Moore, A. L.; Gust, Devens; Groy, Thomas L.; Acta Crystallographica Section E 58 (2002) o1145–o1146; doi:10.1107/S1600536802016975

data_2201284
_publ_section_title
;
 1,4,5,8-Tetramethoxyanthracene
;
_journal_issue                   10
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1145
_journal_page_last               o1146
_journal_paper_doi               10.1107/S1600536802016975
_journal_volume                  58
_journal_year                    2002
_chemical_formula_iupac          'C18 H18 O4'
_chemical_formula_moiety         'C18 H18 O4'
_chemical_formula_sum            'C18 H18 O4'
_chemical_formula_weight         298.32
_chemical_name_systematic        1,4,5,8-tetramethoxyanthracene
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 109.961(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   11.1715(9)
_cell_length_b                   5.9994(5)
_cell_length_c                   11.7159(10)
_cell_measurement_reflns_used    2419
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      27.44
_cell_measurement_theta_min      3.10
_cell_volume                     738.05(11)
_computing_cell_refinement       'SAINT (Bruker, 2002)'
_computing_data_collection       'SMART (Bruker, 2002)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    SHELXTL
_computing_publication_material  SHELXTL
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Bruker, 1997)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker SMART APEX'
_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  0.0430
_diffrn_reflns_av_sigmaI/netI    0.0360
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            6951
_diffrn_reflns_theta_full        27.51
_diffrn_reflns_theta_max         27.51
_diffrn_reflns_theta_min         2.18
_diffrn_standards_decay_%        0.00
_exptl_absorpt_coefficient_mu    0.094
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'clear pale yellow'
_exptl_crystal_density_diffrn    1.342
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Plate
_exptl_crystal_F_000             316
_exptl_crystal_size_max          0.41
_exptl_crystal_size_mid          0.27
_exptl_crystal_size_min          0.11
_refine_diff_density_max         0.197
_refine_diff_density_min         -0.332
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.008
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     100
_refine_ls_number_reflns         1696
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.008
_refine_ls_R_factor_all          0.0778
_refine_ls_R_factor_gt           0.0525
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0745P)^2^] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1269
_refine_ls_wR_factor_ref         0.1395
_reflns_number_gt                1159
_reflns_number_total             1696
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bt6172.cif
_cod_data_source_block           I
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2201284
_cod_database_fobs_code          2201284