Tetramethyl biphenyl-2,3,3',4'-tetracarboxylate
Gao, Guo-wei; Ma, Xiao-yan; Jiang, Yan; Chen, Wei; Men, Jian; Acta Crystallographica Section E 64 (2008) o1779–; doi:10.1107/S1600536808025762

data_2219427
_publ_section_title
;
 Tetramethyl biphenyl-2,3,3',4'-tetracarboxylate
;
_journal_coeditor_code           RK2106
_journal_issue                   9
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1779
_journal_paper_doi               10.1107/S1600536808025762
_journal_volume                  64
_journal_year                    2008
_chemical_formula_iupac          'C20 H18 O8'
_chemical_formula_moiety         'C20 H18 O8'
_chemical_formula_sum            'C20 H18 O8'
_chemical_formula_weight         386.34
_chemical_name_systematic
;
Tetramethyl biphenyl-2,3,3',4'-tetracarboxylate
;
_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
_cell_angle_alpha                90.00
_cell_angle_beta                 108.45(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   14.395(4)
_cell_length_b                   13.453(4)
_cell_length_c                   21.013(3)
_cell_measurement_reflns_used    31
_cell_measurement_temperature    297(2)
_cell_measurement_theta_max      9.18
_cell_measurement_theta_min      4.66
_cell_volume                     3860.1(19)
_computing_cell_refinement       'DIFRAC (Gabe & White, 1993)'
_computing_data_collection       'DIFRAC (Gabe & White, 1993)'
_computing_data_reduction        'NRCVAX (Gabe <i>et al.</i>,  1989)'
_computing_molecular_graphics    'ORTEP-3 (Farrugia, 1997)'
_computing_publication_material  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      297(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Enraf--Nonius CAD-4'
_diffrn_measurement_method       \w/2\q
_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  0.0058
_diffrn_reflns_av_sigmaI/netI    0.0837
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            8168
_diffrn_reflns_theta_full        25.28
_diffrn_reflns_theta_max         25.28
_diffrn_reflns_theta_min         1.83
_diffrn_standards_decay_%        1.823
_diffrn_standards_interval_count 300
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.104
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.330
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1616
_exptl_crystal_size_max          0.45
_exptl_crystal_size_mid          0.42
_exptl_crystal_size_min          0.38
_refine_diff_density_max         0.276
_refine_diff_density_min         -0.227
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.035
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     515
_refine_ls_number_reflns         6906
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.035
_refine_ls_R_factor_all          0.1770
_refine_ls_R_factor_gt           0.0588
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.069P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1369
_refine_ls_wR_factor_ref         0.1633
_reflns_number_gt                2997
_reflns_number_total             6906
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            rk2106.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2219427
_cod_database_fobs_code          2219427