Modular synthesis of benzothiophene-fused pentalenes reveals substituent-dependent antiaromaticity.
Isogai, Ryosuke; Yasui, Kosuke; Fukazawa, Aiko; Chemical science 17 (2026) 3005–3011; doi:10.1039/d5sc09325b

data_1576438
_publ_section_title
;
 Modular synthesis of benzothiophene-fused pentalenes reveals
 substituent-dependent antiaromaticity.
;
_journal_issue                   6
_journal_name_full               'Chemical science'
_journal_page_first              3005
_journal_page_last               3011
_journal_paper_doi               10.1039/d5sc09325b
_journal_volume                  17
_journal_year                    2026
_chemical_formula_moiety         '0.25(C42 H50 S2 Si2)'
_chemical_formula_sum            'C10.5 H12.5 S0.5 Si0.5'
_chemical_formula_weight         168.78
_chemical_name_systematic
6,12-Bis{[tri(i-propyl)silyl]ethynyl}-5,11-dihydropentaleno[1,2-b:4,5-b']dibenzothiophene
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_atom_sites_solution_hydrogens   geom
_audit_block_doi                 10.5517/ccdc.csd.cc2q2mct
_audit_creation_date             2025-11-23
_audit_creation_method
;
Olex2 1.5
(compiled 2025.07.13 svn.rb7424aed for OlexSys, GUI svn.r7314)
;
_audit_update_record
;
2025-11-23 deposited with the CCDC.	2026-01-12 downloaded from the CCDC.
;
_cell_angle_alpha                97.962(2)
_cell_angle_beta                 99.148(2)
_cell_angle_gamma                90.960(2)
_cell_formula_units_Z            4
_cell_length_a                   8.3908(2)
_cell_length_b                   8.8613(2)
_cell_length_c                   13.4687(3)
_cell_measurement_reflns_used    20406
_cell_measurement_temperature    100
_cell_measurement_theta_max      21.6490
_cell_measurement_theta_min      1.7220
_cell_volume                     978.40(4)
_computing_cell_refinement       'CrysAlisPro 1.171.43.119a (Rigaku OD, 2024)'
_computing_data_collection
'CrysAlisPro 1.171.43.119a (Rigaku OD, 2024) (IMPORT)'
_computing_data_reduction        'CrysAlisPro 1.171.43.119a (Rigaku OD, 2024)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2025/1 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      100.00
_diffrn_detector_area_resol_mean 5.8140
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_details
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  t~exp~   \w     \q     \k     \f   Frames
  1  \w      0.00 180.00   1.00    1.00    --    0.00  45.00   0.00  180
  2  \w      0.00 180.00   1.00    1.00    --    0.00  45.00 -90.00  180
  3  \w      0.00 180.00   1.00    1.00    --    0.00  45.00-180.00  180
;
_diffrn_measurement_device       'abstract diffractometer'
_diffrn_measurement_device_type
'esperanto-CrysAlisPro-abstract goniometer imported esperanto images'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_type           synchrotron
_diffrn_radiation_wavelength     0.4108
_diffrn_reflns_av_R_equivalents  0.0400
_diffrn_reflns_av_unetI/netI     0.0213
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            21271
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        14.269
_diffrn_reflns_theta_max         15.470
_diffrn_reflns_theta_min         1.503
_exptl_absorpt_coefficient_mu    0.061
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.80059
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.43.119a (Rigaku Oxford Diffraction, 2024)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear dark red'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   dark
_exptl_crystal_colour_primary    red
_exptl_crystal_density_diffrn    1.146
_exptl_crystal_description       plate
_exptl_crystal_F_000             362
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: hexane, chloroform'
_exptl_crystal_size_max          0.1
_exptl_crystal_size_mid          0.1
_exptl_crystal_size_min          0.01
_refine_diff_density_max         0.745
_refine_diff_density_min         -0.669
_refine_diff_density_rms         0.052
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.083
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     244
_refine_ls_number_reflns         4476
_refine_ls_number_restraints     34
_refine_ls_restrained_S_all      1.079
_refine_ls_R_factor_all          0.0416
_refine_ls_R_factor_gt           0.0394
_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^)+(0.0643P)^2^+0.3164P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1095
_refine_ls_wR_factor_ref         0.1114
_reflns_Friedel_coverage         0.000
_reflns_number_gt                4115
_reflns_number_total             4476
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc09325b2.cif
_cod_data_source_block           4e_re
_cod_original_formula_sum        'C10.50 H12.50 S0.50 Si0.50'
_cod_database_code               1576438
_shelx_shelxl_version_number     2025/1
_shelx_estimated_absorpt_t_max   0.999
_shelx_estimated_absorpt_t_min   0.994
_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
 C13, C14, C15
 with sigma for 1-2 distances of 0.01 and sigma for 1-3 distances of 0.01
 C13A, C14A, C15A
 with sigma for 1-2 distances of 0.01 and sigma for 1-3 distances of 0.01
 C16, C17, C18
 with sigma for 1-2 distances of 0.01 and sigma for 1-3 distances of 0.01
 C16A, C17A, C18A
 with sigma for 1-2 distances of 0.01 and sigma for 1-3 distances of 0.01
3. Uiso/Uaniso restraints and constraints
C13 \\sim C14 \\sim C15: within 2A with sigma of 0.04 and sigma for terminal
atoms of 0.08 within 2A
C13A \\sim C14A \\sim C15A: within 2A with sigma of 0.04 and sigma for terminal
atoms of 0.08 within 2A
C16 \\sim C17 \\sim C18: within 2A with sigma of 0.04 and sigma for terminal
atoms of 0.08 within 2A
C16A \\sim C17A \\sim C18A: within 2A with sigma of 0.04 and sigma for terminal
atoms of 0.08 within 2A
: with sigma of 0.1 and sigma for terminal atoms of 0.2
: with sigma of 0.1 and sigma for terminal atoms of 0.2
4. Others
 Sof(C15A)=Sof(H15D)=Sof(H15E)=Sof(H15F)=Sof(C13A)=Sof(H13A)=Sof(C14A)=
 Sof(H14D)=Sof(H14E)=Sof(H14F)=1-FVAR(1)
 Sof(C13)=Sof(H13)=Sof(C15)=Sof(H15A)=Sof(H15B)=Sof(H15C)=Sof(C14)=Sof(H14A)=
 Sof(H14B)=Sof(H14C)=FVAR(1)
 Sof(C17A)=Sof(H17D)=Sof(H17E)=Sof(H17F)=Sof(C16A)=Sof(H16A)=Sof(C18A)=
 Sof(H18D)=Sof(H18E)=Sof(H18F)=1-FVAR(2)
 Sof(C17)=Sof(H17A)=Sof(H17B)=Sof(H17C)=Sof(C16)=Sof(H16)=Sof(C18)=Sof(H18A)=
 Sof(H18B)=Sof(H18C)=FVAR(2)
5.a Ternary CH refined with riding coordinates:
 C19(H19), C13(H13), C16(H16), C13A(H13A), C16A(H16A)
5.b Aromatic/amide H refined with riding coordinates:
 C8(H8), C5(H5), C7(H7), C6(H6)
5.c Idealised Me refined as rotating group:
 C21(H21A,H21B,H21C), C20(H20A,H20B,H20C), C15(H15A,H15B,H15C), C17(H17A,H17B,
 H17C), C14(H14A,H14B,H14C), C18(H18A,H18B,H18C), C15A(H15D,H15E,H15F),
 C14A(H14D,H14E,H14F), C17A(H17D,H17E,H17F), C18A(H18D,H18E,H18F)
;
_shelx_res_checksum              88293
_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
- Detector area scaling
;