Dimerisation of aryl-substituted bicyclobutanes (BCBs): Revealing a new mode of 1,3-dipolar background reactivity
Werz, Daniel B.; George, Malini; Knyazev, Daniil A.; Świątek, Kamil; von Köller, Heinrich; Chemical Science  (2026) –; doi:10.1039/D6SC01258B

data_1576997
_publ_section_title
;
 Dimerisation of aryl-substituted bicyclobutanes (BCBs): revealing a new
 mode of 1,3-dipolar background reactivity.
;
_journal_issue                   20
_journal_name_full               'Chemical science'
_journal_page_first              10159
_journal_page_last               10167
_journal_paper_doi               10.1039/d6sc01258b
_journal_volume                  17
_journal_year                    2026
_chemical_formula_moiety         'C22 H20 O4'
_chemical_formula_sum            'C22 H20 O4'
_chemical_formula_weight         348.38
_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
_atom_sites_solution_primary     direct
_audit_creation_method
;FinalCif V143 by Daniel Kratzert, Freiburg 2025, 
https://dkratzert.de/finalcif.html
;
_audit_update_record
;
2025-07-15 deposited with the CCDC.	2026-03-31 downloaded from the CCDC.
;
_cell_angle_alpha                99.787(7)
_cell_angle_beta                 92.633(7)
_cell_angle_gamma                99.396(9)
_cell_formula_units_Z            2
_cell_length_a                   6.5073(13)
_cell_length_b                   7.6713(14)
_cell_length_c                   18.211(4)
_cell_measurement_reflns_used    9802
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.153
_cell_measurement_theta_min      2.736
_cell_volume                     881.3(3)
_computing_cell_refinement       'SAINT V8.41'
_computing_data_collection
'Bruker BIS 8.5.5.6/2024-10-24 and APEX6 2024.9-1'
_computing_data_reduction        'SAINT V8.41'
_computing_structure_refinement  'SHELXL-2019/2 (Sheldrick, 2019)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      100(2)
_diffrn_detector                 CPAD
_diffrn_detector_area_resol_mean 7.41
_diffrn_detector_type            'Bruker PHOTON III'
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device       'three-circle diffractometer'
_diffrn_measurement_device_type  'Bruker D8 VENTURE dual wavelength Mo/Cu'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_measurement_specimen_support 'MiTeGen micromount'
_diffrn_radiation_monochromator  'mirror optics'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0704
_diffrn_reflns_av_unetI/netI     0.0220
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.994
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            4419
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.994
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.407
_diffrn_reflns_theta_min         2.276
_diffrn_source                   'microfocus sealed X-ray tube'
_diffrn_source_current           1.4
_diffrn_source_type              'Incoatec I\ms'
_diffrn_source_voltage           50.0
_exptl_absorpt_coefficient_mu    0.090
_exptl_absorpt_correction_T_max  0.745687
_exptl_absorpt_correction_T_min  0.661347
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;TWINABS - Bruker AXS scaling for twinned crystals - Version 2012/1: Krause, L., 
Herbst-Irmer, R., Sheldrick G.M. & Stalke D., J. Appl. Cryst. 48 (2015) 3-10
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.313
_exptl_crystal_description       block
_exptl_crystal_F_000             368
_exptl_crystal_recrystallization_method
'Crystals were obtained at room temperature by gas-phase diffusion of heptaneinto a solution of the compound dissolved in dichloromethane.'
_exptl_crystal_size_max          0.255
_exptl_crystal_size_mid          0.112
_exptl_crystal_size_min          0.047
_refine_diff_density_max         0.281
_refine_diff_density_min         -0.253
_refine_diff_density_rms         0.046
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.081
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     239
_refine_ls_number_reflns         4419
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.081
_refine_ls_R_factor_all          0.0580
_refine_ls_R_factor_gt           0.0481
_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^)+(0.0556P)^2^+0.4251P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1215
_refine_ls_wR_factor_ref         0.1277
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3750
_reflns_number_total             4419
_reflns_threshold_expression     'I > 2\s(I)'
_twin_special_details
'The data was integrated as a 2-component twin.'
_twin_individual_id              2
_twin_individual_twin_matrix_11  -0.06067
_twin_individual_twin_matrix_12  0.00165
_twin_individual_twin_matrix_13  0.98597
_twin_individual_twin_matrix_21  1.00611
_twin_individual_twin_matrix_22  -0.00697
_twin_individual_twin_matrix_23  0.08388
_twin_individual_twin_matrix_31  0.04804
_twin_individual_twin_matrix_32  1.00254
_twin_individual_twin_matrix_33  -0.03542
_cod_data_source_file            d6sc01258b2.cif
_cod_data_source_block           Werz_MG528_a
_cod_depositor_comments
'Adding full bibliography for 1576995--1576999.cif.'
_cod_database_code               1576997
_shelx_shelxl_version_number     2019/3
_shelx_estimated_absorpt_t_min   0.977
_shelx_estimated_absorpt_t_max   0.996
_olex2_diffrn_ambient_temperature_device 'Oxford Cryostream 800'
_shelx_res_checksum              22503