Traceless Directing Groups in Radical Cascades: From Oligoalkynes to Fused Helicenes without Tethered Initiators.
Pati, Kamalkishore; Dos Passos Gomes, Gabriel; Harris, Trevor; Hughes, Audrey; Phan, Hoa; Banerjee, Tanmay; Hanson, Kenneth; Alabugin, Igor V.; Journal of the American Chemical Society 137 (2015) 1165–1180; doi:10.1021/ja510563d

data_4123261
_publ_section_title
;
 Traceless Directing Groups in Radical Cascades: From Oligoalkynes to
 Fused Helicenes without Tethered Initiators.
;
_journal_issue                   3
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              1165
_journal_page_last               1180
_journal_paper_doi               10.1021/ja510563d
_journal_volume                  137
_journal_year                    2015
_chemical_formula_moiety         'C31 H20'
_chemical_formula_sum            'C31 H20'
_chemical_formula_weight         392.47
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_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                 97.56(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   27.281(5)
_cell_length_b                   5.8289(12)
_cell_length_c                   25.615(5)
_cell_measurement_temperature    100(2)
_cell_volume                     4037.8(14)
_computing_cell_refinement       'Saint V8.27(Bruker AXS, 2011)'
_computing_data_collection       'Apex2 V2012.12-0(Bruker AXS, 2012'
_computing_data_reduction        'Saint V8.27(Bruker AXS, 2011)'
_computing_molecular_graphics    'X-Seed (Barbour, 2001)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'Bruker D8 Quest-photon 100 detector'
_diffrn_measurement_method       'profile data from \w 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  0.0726
_diffrn_reflns_av_sigmaI/netI    0.0504
_diffrn_reflns_limit_h_max       38
_diffrn_reflns_limit_h_min       -38
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       36
_diffrn_reflns_limit_l_min       -36
_diffrn_reflns_number            57084
_diffrn_reflns_theta_full        30.27
_diffrn_reflns_theta_max         30.27
_diffrn_reflns_theta_min         2.26
_exptl_absorpt_coefficient_mu    0.073
_exptl_absorpt_correction_T_max  0.9985
_exptl_absorpt_correction_T_min  0.9927
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'SADABS v2012/1(Bruker, 2012)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.291
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             1648
_exptl_crystal_size_max          0.10
_exptl_crystal_size_mid          0.03
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.591
_refine_diff_density_min         -0.343
_refine_diff_density_rms         0.090
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.131
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     559
_refine_ls_number_reflns         12017
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.131
_refine_ls_R_factor_all          0.1127
_refine_ls_R_factor_gt           0.0873
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0839P)^2^+6.7260P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2163
_refine_ls_wR_factor_ref         0.2288
_reflns_number_gt                9050
_reflns_number_total             12017
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja510563d_si_003.cif
_cod_data_source_block
;
;
_cod_depositor_comments
'Adding full bibliography for 4123261--4123264.cif.'
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               4123261