Solid-state [2+2] photodimerization of eniminium salts: stereoselective syntheses of 1,3-diacetylcyclobutanes.
Yamada, Shinji; Honda, Yuka; Chemical communications (Cambridge, England) 60 (2024) 9821–9824; doi:10.1039/d4cc03691c

data_7133494
_publ_section_title
;
 Solid-state [2+2] photodimerization of eniminium salts: stereoselective
 syntheses of 1,3-diacetylcyclobutanes.
;
_journal_issue                   72
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              9821
_journal_page_last               9824
_journal_paper_doi               10.1039/d4cc03691c
_journal_volume                  60
_journal_year                    2024
_chemical_absolute_configuration 'CHOOSE rm ad rmad syn or unk'
_chemical_formula_moiety         'C28 H36 F2 N2'
_chemical_formula_sum            'C28 H36 F2 N2'
_chemical_formula_weight         438.60
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_block_doi                 10.5517/ccdc.csd.cc2kl0gn
_audit_update_record
;
2024-07-14 deposited with the CCDC.	2024-08-12 downloaded from the CCDC.
;
_cell_angle_alpha                90.0000
_cell_angle_beta                 99.9106(11)
_cell_angle_gamma                90.0000
_cell_formula_units_Z            2
_cell_length_a                   9.36553(17)
_cell_length_b                   10.40596(19)
_cell_length_c                   12.2778(2)
_cell_measurement_reflns_used    4906
_cell_measurement_temperature    123
_cell_measurement_theta_max      68.19
_cell_measurement_theta_min      3.65
_cell_volume                     1178.71(4)
_computing_cell_refinement       'RAPID AUTO'
_computing_data_collection       'RAPID AUTO (Rigaku, ????)'
_computing_data_reduction        'RAPID AUTO'
_computing_molecular_graphics    'CrystalStructure 4.2.1'
_computing_publication_material  'CrystalStructure 4.2.1 (Rigaku, 2016)'
_computing_structure_refinement  'SHELXL Version 2014/7 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS Version 2013/1 (Sheldrick, 2008)'
_diffrn_ambient_temperature      123
_diffrn_detector_area_resol_mean 10.000
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Rigaku R-AXIS RAPID'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54187
_diffrn_reflns_av_R_equivalents  0.0316
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            13488
_diffrn_reflns_point_group_measured_fraction_full 0.977
_diffrn_reflns_point_group_measured_fraction_max 0.974
_diffrn_reflns_theta_full        67.687
_diffrn_reflns_theta_max         68.224
_diffrn_reflns_theta_min         3.655
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.659
_exptl_absorpt_correction_T_max  0.906
_exptl_absorpt_correction_T_min  0.821
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'ABSCOR (Rigaku, 1995)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.236
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             472.00
_exptl_crystal_size_max          0.300
_exptl_crystal_size_mid          0.150
_exptl_crystal_size_min          0.150
_refine_diff_density_max         0.27
_refine_diff_density_min         -0.20
_refine_ls_abs_structure_details
;
 Flack x determined using 1496 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.42(19)
_refine_ls_extinction_coef       0.0026(5)
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.121
_refine_ls_hydrogen_treatment    constr
_refine_ls_number_parameters     292
_refine_ls_number_reflns         4206
_refine_ls_number_restraints     1
_refine_ls_R_factor_all          0.0437
_refine_ls_R_factor_gt           0.0355
_refine_ls_shift/su_max          0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0515P)^2^+0.2091P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0926
_refine_ls_wR_factor_ref         0.1017
_reflns_Friedel_coverage         0.840
_reflns_Friedel_fraction_full    0.951
_reflns_Friedel_fraction_max     0.946
_reflns_number_gt                3518
_reflns_number_total             4206
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
_cod_data_source_file            d4cc03691c2.cif
_cod_data_source_block           IMINIUM-DIMER-NaBH4-1
_cod_depositor_comments
'Adding full bibliography for 7133484--7133496.cif.'
_cod_database_code               7133494
_shelx_res_checksum              80629
_shelx_hkl_checksum              6592