Photochemical Skeletal Editing: One-Step Transformation of Diaryl Dithiophenes into Regiodefined Helicenes
Shi, Xiaoli; Mei, Ling; Dong, Chenxi; Zhao, Chunmei; Chen, Chen; Xu, Yimin; Xu, Wan; Li, Chunli; Wang, Guangxia; Ma, Zhiying; Wang, Hua; Chemical Science  (2026) –; doi:10.1039/D6SC01717G

data_1576975
_publ_section_title
;
 Photochemical skeletal editing: one-step transformation of diaryl
 dithiophenes into regiodefined helicenes.
;
_journal_issue                   20
_journal_name_full               'Chemical science'
_journal_page_first              10082
_journal_page_last               10091
_journal_paper_doi               10.1039/d6sc01717g
_journal_volume                  17
_journal_year                    2026
_chemical_formula_moiety         'C46 H36 S3 Si2'
_chemical_formula_sum            'C46 H36 S3 Si2'
_chemical_formula_weight         741.11
_space_group_crystal_system      orthorhombic
_space_group_IT_number           29
_space_group_name_Hall           'P 2c -2ac'
_space_group_name_H-M_alt        'P c a 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2023-10-13
_audit_creation_method
; 
Olex2 1.2 
(compiled 2018.05.29 svn.r3508 for OlexSys, GUI svn.r5506) 
;
_audit_update_record
;
2025-08-08 deposited with the CCDC.	2026-03-25 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   15.9945(10)
_cell_length_b                   11.1752(7)
_cell_length_c                   21.4452(10)
_cell_measurement_reflns_used    3421
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      27.825
_cell_measurement_theta_min      2.417
_cell_volume                     3833.2(4)
_computing_cell_refinement       'SAINT V8.38A (?, 2016)'
_computing_data_collection       'Bruker XSCANS'
_computing_data_reduction        'SAINT V8.38A (?, 2016)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_computing_structure_solution    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      150.0
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker P4'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1299
_diffrn_reflns_av_unetI/netI     0.1141
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -21
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            34366
_diffrn_reflns_point_group_measured_fraction_full 0.974
_diffrn_reflns_point_group_measured_fraction_max 0.960
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.308
_diffrn_reflns_theta_min         2.223
_exptl_absorpt_coefficient_mu    0.289
_exptl_absorpt_correction_T_max  0.0962
_exptl_absorpt_correction_T_min  0.0595
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'SADABS-2016/2 (Bruker,2016/2) was used for absorption correction. wR2(int) was 0.1526 before and 0.0780 after correction. '
_exptl_crystal_colour            yellow
_exptl_crystal_colour_primary    yellow
_exptl_crystal_density_diffrn    1.284
_exptl_crystal_description       block
_exptl_crystal_F_000             1552
_exptl_crystal_size_max          0.14
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.243
_refine_diff_density_min         -0.270
_refine_diff_density_rms         0.054
_refine_ls_abs_structure_details
; 
 Flack x determined using 1719 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   0.03(6)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.003
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     466
_refine_ls_number_reflns         9150
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.003
_refine_ls_R_factor_all          0.1223
_refine_ls_R_factor_gt           0.0558
_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^)+(0.0236P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0869
_refine_ls_wR_factor_ref         0.1072
_reflns_Friedel_coverage         0.875
_reflns_Friedel_fraction_full    0.947
_reflns_Friedel_fraction_max     0.920
_reflns_number_gt                5472
_reflns_number_total             9150
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6sc01717g2.cif
_cod_data_source_block           a_CCDC3
_cod_depositor_comments
'Adding full bibliography for 1576969--1576975.cif.'
_cod_database_code               1576975
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_max   0.966
_shelx_estimated_absorpt_t_min   0.961
_olex2_refinement_description
; 
1. Fixed Uiso 
 At 1.2 times of: 
  All C(H) groups 
 At 1.5 times of: 
  All C(H,H,H) groups 
2.a Aromatic/amide H refined with riding coordinates: 
 C9(H9), C11(H11), C18(H18), C20(H20), C23(H23), C26(H26), C28(H28), C30(H30), 
 C31(H31), C32(H32), C33(H33), C34(H34), C35(H35), C36(H36), C37(H37), C38(H38), 
  C39(H39), C40(H40) 
2.b Idealised Me refined as rotating group: 
 C41(H41A,H41B,H41C), C42(H42A,H42B,H42C), C43(H43A,H43B,H43C), C44(H44A,H44B, 
 H44C), C45(H45A,H45B,H45C), C46(H46A,H46B,H46C) 
;
_olex2_submission_special_instructions 'No special instructions were received'