Three isomeric bis(methoxycarbonyl)[2.2]paracyclophanes
Jones, Peter G.; Hillmer, Jörg; Hopf, Henning; Acta Crystallographica Section C 58 (2002) o301–o304; doi:10.1107/S0108270102005140

data_2012687
_publ_section_title
;
 Three isomeric bis(methoxycarbonyl)[2.2]paracyclophanes
;
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o301
_journal_page_last               o304
_journal_paper_doi               10.1107/S0108270102005140
_journal_volume                  58
_journal_year                    2002
_chemical_formula_moiety         'C20 H20 O4'
_chemical_formula_sum            'C20 H20 O4'
_chemical_formula_weight         324.36
_chemical_name_systematic
;
4,12-bis(methoxycarbonyl)[2.2]paracyclophane
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                90
_cell_angle_beta                 91.90(2)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   8.699(2)
_cell_length_b                   11.790(3)
_cell_length_c                   7.628(2)
_cell_measurement_reflns_used    50
_cell_measurement_temperature    178(2)
_cell_measurement_theta_max      12
_cell_measurement_theta_min      10
_cell_volume                     781.9(3)
_computing_cell_refinement       'P3 Software'
_computing_data_collection       'P3 Software (Nicolet, 1987)'
_computing_data_reduction        'XDISK (Nicolet, 1987)'
_computing_molecular_graphics    'XP (Siemens, 1994)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      178(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Nicolet R3'
_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  0.016
_diffrn_reflns_av_sigmaI/netI    0.026
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            2989
_diffrn_reflns_theta_full        27.49
_diffrn_reflns_theta_max         27.49
_diffrn_reflns_theta_min         3.18
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 147
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.095
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.378
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       tablet
_exptl_crystal_F_000             344
_exptl_crystal_size_max          0.7
_exptl_crystal_size_mid          0.4
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.27
_refine_diff_density_min         -0.24
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.059
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     110
_refine_ls_number_reflns         1789
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.059
_refine_ls_R_factor_all          0.062
_refine_ls_R_factor_gt           0.045
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.064P)^2^+0.341P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.116
_refine_ls_wR_factor_ref         0.131
_reflns_number_gt                1390
_reflns_number_total             1789
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bm1493.cif
_cod_data_source_block           IVd
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2012687
_cod_database_fobs_code          2012687