Five bicyclo[3.3.0]octa-2,6-dienes
Vega, Andrés; Donoso-Tauda, Oscar; Ibañez, Andres; Escobar, Carlos A.; Acta Crystallographica Section C 64 (2008) o199–o204; doi:10.1107/S0108270108004290

data_2016552
_publ_section_title
;
 Five bicyclo[3.3.0]octa-2,6-dienes
;
_journal_coeditor_code           GG3136
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o199
_journal_page_last               o204
_journal_paper_doi               10.1107/S0108270108004290
_journal_volume                  64
_journal_year                    2008
_chemical_formula_iupac          'C20 H22 O12'
_chemical_formula_moiety         'C20 H22 O12'
_chemical_formula_sum            'C20 H22 O12'
_chemical_formula_weight         454.38
_chemical_melting_point          97.2(8)
_chemical_name_systematic
;
tetramethyl
<i>cis</i>,<i>cis</i>-3,7-diacetoxybicyclo[3.3.0]octa-2,6-diene-
2,4-<i>exo</i>,6,8-<i>exo</i>-tetracarboxylate
;
_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           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.5070(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.0095(5)
_cell_length_b                   20.9263(12)
_cell_length_c                   10.1881(6)
_cell_measurement_reflns_used    1758
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      20.362
_cell_measurement_theta_min      2.2756
_cell_volume                     2133.9(2)
_computing_cell_refinement       'SAINT-NT (Bruker, 1999)'
_computing_data_collection       'SMART-NT (Bruker, 2001)'
_computing_data_reduction        'SAINT-NT (Bruker, 1999)'
_computing_molecular_graphics    'SHELXTL-NT (Bruker, 1999)'
_computing_publication_material  'SHELXTL-NT (Bruker, 1999)'
_computing_structure_refinement  'SHELXTL-NT (Bruker, 1999)'
_computing_structure_solution    'SHELXTL-NT (Bruker, 1999)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Siemens SMART CCD area-detector'
_diffrn_measurement_method       '\f and \w scans'
_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  0.0574
_diffrn_reflns_av_sigmaI/netI    0.0486
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            13188
_diffrn_reflns_theta_full        25.04
_diffrn_reflns_theta_max         25.04
_diffrn_reflns_theta_min         1.95
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    0.119
_exptl_absorpt_correction_T_max  0.986
_exptl_absorpt_correction_T_min  0.983
_exptl_absorpt_correction_type   refdelf
_exptl_absorpt_process_details   '(SADABS; Bruker, 1999)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.414
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             952
_exptl_crystal_size_max          0.34
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.286
_refine_diff_density_min         -0.242
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.910
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     295
_refine_ls_number_reflns         3766
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.910
_refine_ls_R_factor_all          0.0807
_refine_ls_R_factor_gt           0.0496
_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^)+(0.0848P)^2^+0.784P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1223
_refine_ls_wR_factor_ref         0.1458
_reflns_number_gt                2596
_reflns_number_total             3766
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            gg3136.cif
_cod_data_source_block           V
_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.

'_geom_torsion_publ_flag' value 'Y' changed to 'y' according
to '/home/saulius/struct/CIF-dictionaries/cif_core.dic' dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29 (14 times).

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

The following automatic conversions were performed:

'_chemical_melting_point' value '96.5-98' was changed to '97.2(8)' -
the average value was taken and precision was estimated.

Automatic conversion script
Id: cif_fix_values 1646 2011-03-28 12:23:43Z adriana 

The following automatic conversions were performed:

'_chemical_melting_point' value '96.5-98' was changed to '97.2(8)' -
the average value was taken and precision was
estimated.

'_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.

'_geom_torsion_publ_flag' value 'Y' changed to 'y'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29 (14
times).

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2016552
_cod_database_fobs_code          2016552