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_1576971
_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         '2(C38 H32 S3 Si2), 2(C H Cl3)'
_chemical_formula_sum            'C78 H66 Cl6 S6 Si4'
_chemical_formula_weight         1520.72
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2023-12-21
_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                 81.889(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   37.2215(17)
_cell_length_b                   16.0807(7)
_cell_length_c                   13.1675(5)
_cell_measurement_reflns_used    8655
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      27.564
_cell_measurement_theta_min      2.211
_cell_volume                     7802.5(6)
_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 0.998
_diffrn_measured_fraction_theta_max 0.992
_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  0.1221
_diffrn_reflns_av_unetI/netI     0.1617
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.992
_diffrn_reflns_limit_h_max       49
_diffrn_reflns_limit_h_min       -47
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            62127
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.992
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.362
_diffrn_reflns_theta_min         2.011
_exptl_absorpt_coefficient_mu    0.484
_exptl_absorpt_correction_T_max  0.2627
_exptl_absorpt_correction_T_min  0.1519
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'SADABS-2016/2 (Bruker,2016/2) was used for absorption correction. wR2(int) was 0.1476 before and 0.0922 after correction. '
_exptl_crystal_colour            yellow
_exptl_crystal_colour_primary    yellow
_exptl_crystal_density_diffrn    1.295
_exptl_crystal_description       block
_exptl_crystal_F_000             3152
_exptl_crystal_size_max          0.21
_exptl_crystal_size_mid          0.19
_exptl_crystal_size_min          0.09
_refine_diff_density_max         0.568
_refine_diff_density_min         -0.884
_refine_diff_density_rms         0.095
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.028
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     952
_refine_ls_number_reflns         19376
_refine_ls_number_restraints     192
_refine_ls_restrained_S_all      1.027
_refine_ls_R_factor_all          0.1729
_refine_ls_R_factor_gt           0.0850
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1030P)^2^+0.6850P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2002
_refine_ls_wR_factor_ref         0.2494
_reflns_Friedel_coverage         0.000
_reflns_number_gt                9477
_reflns_number_total             19376
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6sc01717g2.cif
_cod_data_source_block           b
_cod_depositor_comments
'Adding full bibliography for 1576969--1576975.cif.'
_cod_database_code               1576971
_shelx_shelxl_version_number     2018/3
_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. Rigid bond restraints 
 Si1, C75A, C76A, C78A, C75B, C76B, C78B 
 with sigma for 1-2 distances of 0.001 and sigma for 1-3 distances of 0.001 
 Si4, C72A, C74A, C77A, C72B, C74B, C77B 
 with sigma for 1-2 distances of 0.001 and sigma for 1-3 distances of 0.001 
 Si2, C68A, C70A, C73A, C68B, C70B, C73B 
 with sigma for 1-2 distances of 0.001 and sigma for 1-3 distances of 0.001 
3. Uiso/Uaniso restraints and constraints 
Si1 \\sim C75A \\sim C76A \\sim C78A \\sim C75B \\sim C76B \\sim C78B: within 
2A with sigma of 0.001 and sigma for terminal atoms of 0.002 
Si4 \\sim C72A \\sim C74A \\sim C77A \\sim C72B \\sim C74B \\sim C77B: within 
2A with sigma of 0.001 and sigma for terminal atoms of 0.002 
Si2 \\sim C68A \\sim C70A \\sim C73A \\sim C68B \\sim C70B \\sim C73B: within 
2A with sigma of 0.001 and sigma for terminal atoms of 0.002 
4. Others 
 Sof(C75B)=Sof(H75A)=Sof(H75B)=Sof(H75C)=Sof(C76B)=Sof(H76A)=Sof(H76B)= 
 Sof(H76C)=Sof(C78B)=Sof(H78A)=Sof(H78B)=Sof(H78C)=1-FVAR(1) 
 Sof(C75A)=Sof(H75D)=Sof(H75E)=Sof(H75F)=Sof(C76A)=Sof(H76D)=Sof(H76E)= 
 Sof(H76F)=Sof(C78A)=Sof(H78D)=Sof(H78E)=Sof(H78F)=FVAR(1) 
 Sof(C72B)=Sof(H72A)=Sof(H72B)=Sof(H72C)=Sof(C74B)=Sof(H74A)=Sof(H74B)= 
 Sof(H74C)=Sof(C77B)=Sof(H77A)=Sof(H77B)=Sof(H77C)=1-FVAR(2) 
 Sof(C74A)=Sof(H74D)=Sof(H74E)=Sof(H74F)=Sof(C72A)=Sof(H72D)=Sof(H72E)= 
 Sof(H72F)=Sof(C77A)=Sof(H77D)=Sof(H77E)=Sof(H77F)=FVAR(2) 
 Sof(C68B)=Sof(H68A)=Sof(H68B)=Sof(H68C)=Sof(C70B)=Sof(H70A)=Sof(H70B)= 
 Sof(H70C)=Sof(C73B)=Sof(H73A)=Sof(H73B)=Sof(H73C)=1-FVAR(3) 
 Sof(C70A)=Sof(H70D)=Sof(H70E)=Sof(H70F)=Sof(C73A)=Sof(H73D)=Sof(H73E)= 
 Sof(H73F)=Sof(C68A)=Sof(H68D)=Sof(H68E)=Sof(H68F)=FVAR(3) 
5.a Ternary CH refined with riding coordinates: 
 C65(H65), C66(H66) 
5.b Aromatic/amide H refined with riding coordinates: 
 C12(H12), C14(H14), C18(H18), C25(H25), C26(H26), C30(H30), C34(H34), 
 C37(H37), C38(H38), C39(H39), C40(H40), C41(H41), C44(H44), C45(H45), C47(H47), 
  C48(H48), C49(H49), C50(H50), C51(H51), C52(H52), C53(H53), C56(H56), 
 C57(H57), C59(H59), C60(H60), C61(H61), C63(H63), C64(H64) 
5.c Idealised Me refined as rotating group: 
 C67(H67A,H67B,H67C), C68B(H68A,H68B,H68C), C69(H69A,H69B,H69C), C70B(H70A, 
 H70B,H70C), C71(H71A,H71B,H71C), C72B(H72A,H72B,H72C), C73B(H73A,H73B,H73C), 
 C74B(H74A,H74B,H74C), C75B(H75A,H75B,H75C), C76B(H76A,H76B,H76C), C77B(H77A, 
 H77B,H77C), C78B(H78A,H78B,H78C), C75A(H75D,H75E,H75F), C76A(H76D,H76E,H76F), 
 C78A(H78D,H78E,H78F), C74A(H74D,H74E,H74F), C72A(H72D,H72E,H72F), C77A(H77D, 
 H77E,H77F), C70A(H70D,H70E,H70F), C73A(H73D,H73E,H73F), C68A(H68D,H68E,H68F) 
;
_shelx_res_checksum              75702
_shelx_fab_checksum              37932
_olex2_submission_special_instructions 'No special instructions were received'