2a,8a-Dichloro-1-(2-ethynylphenyl)-2a,8a-dihydrocyclobuta[<i>b</i>]naphthalene-3,8-dione
Hui-Ying An; Jian-Hua Xu; Shea-Lin Ng; Hoong-Kun Fun; Acta Crystallographica Section E 63 (2007) o948–o950; doi:10.1107/S160053680700342X

data_2212108
_publ_section_title
2a,8a-Dichloro-1-(2-ethynylphenyl)-2a,8a-dihydrocyclobuta[<i>b</i>]naphthalene-3,8-dione
_journal_coeditor_code           CI2281
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o948
_journal_page_last               o950
_journal_paper_doi               10.1107/S160053680700342X
_journal_volume                  63
_journal_year                    2007
_chemical_formula_iupac          'C20 H10 Cl2 O2'
_chemical_formula_moiety         'C20 H10 Cl2 O2'
_chemical_formula_sum            'C20 H10 Cl2 O2'
_chemical_formula_weight         353.18
_chemical_name_systematic
;
2a,8a-Dichloro-1-(2-ethynylphenyl)-2a,8a-dihydrocyclobuta[b]naphthalene-
3,8-dione
;
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   16.0627(2)
_cell_length_b                   8.04820(10)
_cell_length_c                   24.0821(3)
_cell_measurement_reflns_used    9833
_cell_measurement_temperature    100.00(10)
_cell_measurement_theta_max      37.50
_cell_measurement_theta_min      2.54
_cell_volume                     3113.23(7)
_computing_cell_refinement       APEX2
_computing_data_collection       'APEX2 (Bruker, 2005)'
_computing_data_reduction        'SAINT (Bruker, 2005)'
_computing_molecular_graphics    SHELXTL
_computing_publication_material
;
SHELXTL and PLATON (Spek, 2003)
;
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Sheldrick, 1998)'
_diffrn_ambient_temperature      100.00(10)
_diffrn_detector_area_resol_mean 8.33
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type
;
Bruker SMART APEX2 CCD area-detector
;
_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  0.0341
_diffrn_reflns_av_sigmaI/netI    0.0201
_diffrn_reflns_limit_h_max       27
_diffrn_reflns_limit_h_min       -27
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       41
_diffrn_reflns_limit_l_min       -41
_diffrn_reflns_number            127742
_diffrn_reflns_theta_full        37.50
_diffrn_reflns_theta_max         37.50
_diffrn_reflns_theta_min         2.54
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.426
_exptl_absorpt_correction_T_max  0.8825
_exptl_absorpt_correction_T_min  0.8216
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Bruker, 2005)'
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    1.507
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Block
_exptl_crystal_F_000             1440
_exptl_crystal_size_max          0.47
_exptl_crystal_size_mid          0.41
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.548
_refine_diff_density_min         -0.266
_refine_ls_abs_structure_details 'Flack (1983), 8036 Friedel pairs'
_refine_ls_abs_structure_Flack   0.54(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.043
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     434
_refine_ls_number_reflns         16384
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.043
_refine_ls_R_factor_all          0.0363
_refine_ls_R_factor_gt           0.0323
_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^)+(0.0511P)^2^+0.4718P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0831
_refine_ls_wR_factor_ref         0.0856
_reflns_number_gt                15176
_reflns_number_total             16384
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ci2281.cif
_cod_data_source_block           I
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic' changed to 'orthorhombic'
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 'Orthorhombic' changed to
'orthorhombic' 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_database_code               2212108
_cod_database_fobs_code          2212108