Domino Fragmentations in Traceless Directing Groups of Radical Cascades: Evidence for the Formation of Alkoxy Radicals via C-O Scission.
Harris, Trevor; Gomes, Gabriel Dos Passos; Clark, Ronald J.; Alabugin, Igor V.; The Journal of organic chemistry 81 (2016) 6007–6017; doi:10.1021/acs.joc.6b01052

data_4036948
_publ_section_title
;
 Domino Fragmentations in Traceless Directing Groups of Radical Cascades:
 Evidence for the Formation of Alkoxy Radicals via C-O Scission.
;
_journal_issue                   14
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              6007
_journal_page_last               6017
_journal_paper_doi               10.1021/acs.joc.6b01052
_journal_volume                  81
_journal_year                    2016
_chemical_formula_moiety         'C25 H18 O2'
_chemical_formula_sum            'C25 H18 O2'
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_space_group_crystal_system      orthorhombic
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_space_group_name_Hall           'P 2c -2ac'
_space_group_name_H-M_alt        'P c a 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2013
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   32.136(2)
_cell_length_b                   14.7792(11)
_cell_length_c                   7.6234(6)
_cell_measurement_reflns_used    9997
_cell_measurement_temperature    103(2)
_cell_measurement_theta_max      28.72
_cell_measurement_theta_min      2.35
_cell_volume                     3620.7(5)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_diffrn_ambient_temperature      103(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.966
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0419
_diffrn_reflns_av_unetI/netI     0.0338
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.966
_diffrn_reflns_limit_h_max       44
_diffrn_reflns_limit_h_min       -44
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            44113
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.943
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         29.473
_diffrn_reflns_theta_min         2.348
_exptl_absorpt_coefficient_mu    0.080
_exptl_absorpt_correction_T_max  0.7459
_exptl_absorpt_correction_T_min  0.6991
_exptl_absorpt_correction_type   empiical
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.286
_exptl_crystal_description       flat
_exptl_crystal_F_000             1472
_exptl_crystal_size_max          0.206
_exptl_crystal_size_mid          0.175
_exptl_crystal_size_min          0.094
_refine_diff_density_max         0.267
_refine_diff_density_min         -0.210
_refine_diff_density_rms         0.037
_refine_ls_abs_structure_details
; 
 Flack x determined using 3711 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons and Flack (2004), Acta Cryst. A60, s61). 
;
_refine_ls_abs_structure_Flack   -0.3(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.018
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     487
_refine_ls_number_reflns         9507
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.018
_refine_ls_R_factor_all          0.0404
_refine_ls_R_factor_gt           0.0355
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0393P)^2^+0.6852P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0813
_refine_ls_wR_factor_ref         0.0839
_reflns_Friedel_coverage         0.823
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.918
_reflns_number_gt                8699
_reflns_number_total             9507
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo6b01052_si_001.cif
_cod_data_source_block           igor106
_cod_database_code               4036948
_shelx_estimated_absorpt_t_min   0.6991
_shelx_estimated_absorpt_t_max   0.7456
_shelxl_version_number           2013-4
_shelx_res_checksum              87557
_shelx_hkl_checksum              24607