Evidence for Facile Atropisomerism and Simple (Non-Nucleophilic) Biradical-Forming Cycloaromatization within Kedarcidin Chromophore Aglycon
Andrew G. Myers; Alexander R. Hurd; Philip C. Hogan; Journal of the American Chemical Society 124 (2002) 4583–4585; doi:10.1021/ja020152p

data_4114764
_publ_section_title
;
 Evidence for Facile Atropisomerism and Simple (Non-Nucleophilic)
 Biradical-Forming Cycloaromatization within Kedarcidin Chromophore
 Aglycon
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              4583
_journal_page_last               4585
_journal_paper_doi               10.1021/ja020152p
_journal_volume                  124
_journal_year                    2002
_chemical_formula_sum            'C30 H32 Br Cl N2 O8'
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_symmetry_space_group_name_Hall  'P 1'
_symmetry_space_group_name_H-M   'P 1'
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_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                81.077(7)
_cell_angle_beta                 90.000(7)
_cell_angle_gamma                90.000(8)
_cell_formula_units_Z            2
_cell_length_a                   6.332(2)
_cell_length_b                   12.636(5)
_cell_length_c                   19.532(8)
_cell_measurement_temperature    213(2)
_cell_volume                     1543.9(10)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      213(2)
_diffrn_measured_fraction_theta_full 0.872
_diffrn_measured_fraction_theta_max 0.872
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega 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  0.1079
_diffrn_reflns_av_sigmaI/netI    0.0909
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -25
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_diffrn_reflns_theta_full        28.60
_diffrn_reflns_theta_max         28.60
_diffrn_reflns_theta_min         1.06
_exptl_absorpt_coefficient_mu    1.469
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.428
_exptl_crystal_density_meas      -60
_exptl_crystal_description       block
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_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.50
_refine_diff_density_max         2.480
_refine_diff_density_min         -1.830
_refine_diff_density_rms         0.242
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.01(2)
_refine_ls_extinction_method     none
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_refine_ls_matrix_type           full
_refine_ls_number_parameters     757
_refine_ls_number_reflns         7880
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_refine_ls_R_factor_all          0.1667
_refine_ls_R_factor_gt           0.1306
_refine_ls_shift/su_max          0.018
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.2000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.3692
_refine_ls_wR_factor_ref         0.3995
_reflns_number_gt                5633
_reflns_number_total             7880
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja020152p.cif
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_cod_original_cell_volume        1544.0(10)
_cod_database_code               4114764