A fragment-based approach toward substituted trioxa[7]helicenes.
Kelgtermans, Hans; Dobrzańska, Liliana; Van Meervelt, Luc; Dehaen, Wim; Organic letters 14 (2012) 5200–5203; doi:10.1021/ol3023209

data_1516082
_publ_section_title
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 A fragment-based approach toward substituted trioxa[7]helicenes.
;
_journal_issue                   20
_journal_name_full               'Organic letters'
_journal_page_first              5200
_journal_page_last               5203
_journal_paper_doi               10.1021/ol3023209
_journal_volume                  14
_journal_year                    2012
_chemical_formula_moiety         'C29 H20 N2 O7'
_chemical_formula_sum            'C29 H20 N2 O7'
_chemical_formula_weight         508.47
_chemical_name_common            work
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                83.667(2)
_cell_angle_beta                 73.144(2)
_cell_angle_gamma                75.898(2)
_cell_formula_units_Z            4
_cell_length_a                   10.6771(4)
_cell_length_b                   13.0878(5)
_cell_length_c                   18.3378(6)
_cell_measurement_reflns_used    4979
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      71.266
_cell_measurement_theta_min      2.52
_cell_volume                     2376.35(15)
_computing_cell_refinement       'SAINT PLUS(Bruker, 2003)'
_computing_data_collection       'SMART (Bruker, 2002)'
_computing_data_reduction        'SAINT PLUS'
_computing_molecular_graphics    'Mercury (Macrae et al., 2008)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.980
_diffrn_measured_fraction_theta_max 0.963
_diffrn_measurement_device_type  'Bruker SMART 6000'
_diffrn_measurement_method       '\w and \f'
_diffrn_radiation_monochromator  'crossed G\"obel mirrors'
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0625
_diffrn_reflns_av_sigmaI/netI    0.0445
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            38423
_diffrn_reflns_theta_full        67.50
_diffrn_reflns_theta_max         71.34
_diffrn_reflns_theta_min         2.52
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.857
_exptl_absorpt_correction_T_max  0.9424
_exptl_absorpt_correction_T_min  0.8272
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS in SAINT-Plus (Bruker, 2003)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.421
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1056
_exptl_crystal_size_max          0.23
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.07
_refine_diff_density_max         0.402
_refine_diff_density_min         -0.282
_refine_diff_density_rms         0.055
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.034
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     691
_refine_ls_number_reflns         8894
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.034
_refine_ls_R_factor_all          0.0717
_refine_ls_R_factor_gt           0.0530
_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^)+(0.0787P)^2^+0.1850P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1280
_refine_ls_wR_factor_ref         0.1389
_reflns_number_gt                6804
_reflns_number_total             8894
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            Cmp13.CIF
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               1516082