Asymmetric Synthesis of Second-Generation Light-Driven Molecular Motors.
van Leeuwen, Thomas; Danowski, Wojciech; Otten, Edwin; Wezenberg, Sander J.; Feringa, Ben L.; The Journal of organic chemistry 82 (2017) 5027–5033; doi:10.1021/acs.joc.7b00852

data_4037497
_publ_section_title
;
 Asymmetric Synthesis of Second-Generation Light-Driven Molecular Motors.
;
_journal_issue                   10
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              5027
_journal_page_last               5033
_journal_paper_doi               10.1021/acs.joc.7b00852
_journal_volume                  82
_journal_year                    2017
_chemical_absolute_configuration ad
_chemical_formula_sum            'C28 H20 Br2'
_chemical_formula_weight         516.26
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.2152(3)
_cell_length_b                   14.0726(7)
_cell_length_c                   20.7911(10)
_cell_measurement_reflns_used    9368
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.71
_cell_measurement_theta_min      2.99
_cell_volume                     2111.06(17)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    SHELXT
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.996
_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  0.0283
_diffrn_reflns_av_unetI/netI     0.0231
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            41974
_diffrn_reflns_point_group_measured_fraction_full 0.994
_diffrn_reflns_point_group_measured_fraction_max 0.991
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.735
_diffrn_reflns_theta_min         2.895
_exptl_absorpt_coefficient_mu    3.853
_exptl_absorpt_correction_T_max  0.7458
_exptl_absorpt_correction_T_min  0.6132
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.624
_exptl_crystal_description       block
_exptl_crystal_F_000             1032
_exptl_crystal_size_max          0.250
_exptl_crystal_size_mid          0.250
_exptl_crystal_size_min          0.250
_refine_diff_density_max         0.247
_refine_diff_density_min         -0.434
_refine_diff_density_rms         0.070
_refine_ls_abs_structure_details
;
 Flack x determined using 2182 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.008(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.084
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     273
_refine_ls_number_reflns         5424
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.084
_refine_ls_R_factor_all          0.0170
_refine_ls_R_factor_gt           0.0157
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0182P)^2^+0.2190P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0392
_refine_ls_wR_factor_ref         0.0395
_reflns_Friedel_coverage         0.751
_reflns_Friedel_fraction_full    0.989
_reflns_Friedel_fraction_max     0.985
_reflns_number_gt                5215
_reflns_number_total             5424
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo7b00852_si_001.cif
_cod_data_source_block           mo_molan448_0m_a
_cod_database_code               4037497
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.446
_shelx_estimated_absorpt_t_max   0.446
_shelx_res_checksum              50777
_shelx_hkl_checksum              41431