The natural naphthoquinone sterekunthal-B
K. Ravikumar; B. Sridhar; S. Venkat Reddy; U. Sampath Kumar; J. Madhusudana Rao; Acta Crystallographica Section E 61 (2005) o494–o496; doi:10.1107/S160053680500259X

data_2205014
_publ_section_title
;
 The natural naphthoquinone sterekunthal-B
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o494
_journal_page_last               o496
_journal_paper_doi               10.1107/S160053680500259X
_journal_volume                  61
_journal_year                    2005
_chemical_formula_iupac          'C20 H18 O4'
_chemical_formula_moiety         'C20 H18 O4'
_chemical_formula_sum            'C20 H18 O4'
_chemical_formula_weight         322.34
_chemical_name_systematic
;
15,18-dimethyl-5-dioxo-14-
oxapentacyclo[11.4.1.0^2,15^.0^4,13^.0^6,11^]octadeca-3,6,8,10-tetraene-
18-carbaldehyde
;
_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            4
_cell_length_a                   13.3078(19)
_cell_length_b                   7.9299(11)
_cell_length_c                   15.168(2)
_cell_measurement_reflns_used    6143
_cell_measurement_temperature    273(2)
_cell_measurement_theta_max      27.94
_cell_measurement_theta_min      2.68
_cell_volume                     1600.7(4)
_computing_cell_refinement       'SAINT (Bruker, 2001)'
_computing_data_collection       'SMART (Bruker, 2001)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    'SHELXTL/PC (Sheldrick, 1990)'
_computing_publication_material  'SHELXL97 and PARST (Nardelli, 1995)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      273(2)
_diffrn_measured_fraction_theta_full 0.975
_diffrn_measured_fraction_theta_max 0.975
_diffrn_measurement_device       'Bruker SMART APEX CCD area-detector'
_diffrn_measurement_device_type  '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  0.0173
_diffrn_reflns_av_sigmaI/netI    0.0138
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            9248
_diffrn_reflns_theta_full        27.96
_diffrn_reflns_theta_max         27.96
_diffrn_reflns_theta_min         2.99
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.093
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    1.338
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             680
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.201
_refine_diff_density_min         -0.235
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.026
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     219
_refine_ls_number_reflns         1954
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.026
_refine_ls_R_factor_all          0.0399
_refine_ls_R_factor_gt           0.0386
_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^)+(0.0762P)^2^+0.1221P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1027
_refine_ls_wR_factor_ref         0.1049
_reflns_number_gt                1879
_reflns_number_total             1954
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bt6594.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               2205014
_cod_database_fobs_code          2205014