Cycloaddition products of tricyclo[6.2.1.0^2,7^]undeca-2(7),4,9-triene-3,6-dione
Pattabhi, V.; Banumathi, S.; Goverdhan, M.; Padma, S.; Acta Crystallographica Section C 50 (1994) 594–597; doi:10.1107/S0108270193007814

data_2009615
_publ_section_title
;
 Cycloaddition products of
 tricyclo[6.2.1.0^2,7^]undeca-2(7),4,9-triene-3,6-dione
;
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              594
_journal_page_last               597
_journal_paper_doi               10.1107/S0108270193007814
_journal_volume                  50
_journal_year                    1994
_chemical_formula_moiety         'C21 H18 O2'
_chemical_formula_sum            'C21 H18 O2'
_chemical_formula_weight         302.37
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_type_scat_source           IntTabIV
_cell_angle_alpha                90.
_cell_angle_beta                 90.
_cell_angle_gamma                90.
_cell_formula_units_Z            4
_cell_length_a                   7.9250(10)
_cell_length_b                   9.281(2)
_cell_length_c                   20.918(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293
_cell_measurement_theta_max      30
_cell_measurement_theta_min      20
_cell_volume                     1538.6(4)
_diffrn_measurement_device       'Enraf-Nonius CAD-4'
_diffrn_measurement_method       \w-2\q
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.5418
_diffrn_reflns_av_R_equivalents  0.03
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            1752
_diffrn_reflns_theta_max         70
_diffrn_standards_decay_%        <2.8
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.62
_exptl_absorpt_correction_T_max  0.96
_exptl_absorpt_correction_T_min  0.73
_exptl_absorpt_correction_type   empirical
_exptl_crystal_colour            'greenish yellow'
_exptl_crystal_density_diffrn    1.31
_exptl_crystal_description       rhombus
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.27
_refine_diff_density_min         -0.27
_refine_ls_extinction_coef       1.35E-6
_refine_ls_extinction_method     'Zachariasen (1963)'
_refine_ls_goodness_of_fit_obs   3.25
_refine_ls_hydrogen_treatment    refall
_refine_ls_number_parameters     280
_refine_ls_number_reflns         1567
_refine_ls_R_factor_obs          0.068
_refine_ls_shift/esd_max         0.03
_refine_ls_structure_factor_coef F
_refine_ls_weighting_scheme
;4(F~o~)^2^/\s^2^(F~o~)^2^ where \s(F~o~)^2^ = [\s^2^(I)
+ (0.05I)^2^]^1/2^/Lp
;
_refine_ls_wR_factor_obs         0.099
_reflns_number_observed          1567
_reflns_number_total             1701
_reflns_observed_criterion       I>2.5\s(I)
_cod_data_source_file            ha1052.cif
_cod_data_source_block           ha1052_structure_1_of_2
_cod_database_code               2009615