An elusive thermal [2 + 2] cycloaddition driven by visible light photocatalysis: tapping into strain to access C2-symmetric tricyclic rings.
Singh, Kamaljeet; Trinh, Winston; Latifi, Reza; Weaver, Jimmie D.; Organic & biomolecular chemistry 17 (2019) 1854–1861; doi:10.1039/c8ob01273c

data_7156298
_publ_section_title
;
 An elusive thermal [2 + 2] cycloaddition driven by visible light
 photocatalysis: tapping into strain to access C2-symmetric tricyclic
 rings.
;
_journal_issue                   7
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              1854
_journal_page_last               1861
_journal_paper_doi               10.1039/c8ob01273c
_journal_volume                  17
_journal_year                    2019
_chemical_formula_moiety         'C26 H30 F2 O2'
_chemical_formula_sum            'C26 H30 F2 O2'
_chemical_formula_weight         412.50
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_date             2016-05-11
_audit_creation_method
;
Olex2 1.2
(compiled 2015.01.26 svn.r3150 for OlexSys, GUI svn.r4998)
;
_audit_update_record
;
2017-10-22 deposited with the CCDC.
2018-06-25 downloaded from the CCDC.
;
_cell_angle_alpha                73.103(3)
_cell_angle_beta                 81.352(3)
_cell_angle_gamma                77.937(3)
_cell_formula_units_Z            2
_cell_length_a                   8.719(2)
_cell_length_b                   9.572(2)
_cell_length_c                   12.839(3)
_cell_measurement_reflns_used    9114
_cell_measurement_temperature    100
_cell_measurement_theta_max      30.66
_cell_measurement_theta_min      2.26
_cell_volume                     998.0(4)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2014 (Sheldrick 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_diffrn_ambient_temperature      100
_diffrn_measured_fraction_theta_full 0.960
_diffrn_measured_fraction_theta_max 0.960
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0746
_diffrn_reflns_av_unetI/netI     0.0517
_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       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            19956
_diffrn_reflns_theta_full        26.02
_diffrn_reflns_theta_max         26.02
_diffrn_reflns_theta_min         1.67
_diffrn_source                   'fine-focus sealed tube'
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.097
_exptl_absorpt_correction_T_max  0.7461
_exptl_absorpt_correction_T_min  0.5632
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2014/5 (Bruker,2014/5) was used for absorption correction.
wR2(int) was 0.1386 before and 0.0765 after correction.
The Ratio of minimum to maximum transmission is 0.7549.
The \l/2 correction factor is 0.00150.
;
_exptl_crystal_colour            'clear light colourless'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   light
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.373
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Rectangle
_exptl_crystal_F_000             440
_exptl_crystal_size_max          0.103
_exptl_crystal_size_mid          0.087
_exptl_crystal_size_min          0.05
_refine_diff_density_max         1.011
_refine_diff_density_min         -0.326
_refine_diff_density_rms         0.061
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.032
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     277
_refine_ls_number_reflns         3773
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.032
_refine_ls_R_factor_all          0.0720
_refine_ls_R_factor_gt           0.0526
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0620P)^2^+0.8394P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1284
_refine_ls_wR_factor_ref         0.1389
_reflns_number_gt                2923
_reflns_number_total             3773
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c8ob01273c2.cif
_cod_data_source_block           bisphen_fi_abs
_cod_depositor_comments
'Adding full bibliography for 7156298--7156300.cif.'
_cod_database_code               7156298
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All O(H) groups
2.a Ternary CH refined with riding coordinates:
 C10(H10), C8(H8), C3(H3), C1(H1A)
2.b Secondary CH2 refined with riding coordinates:
 C11(H11A,H11B), C12(H12A,H12B), C13(H13A,H13B), C14(H14A,H14B), C4(H4A,H4B),
 C5(H5A,H5B), C6(H6A,H6B), C7(H7A,H7B)
2.c Aromatic/amide H refined with riding coordinates:
 C19(H19), C20(H20), C26(H26), C25(H25), C22(H22), C23(H23), C16(H16), C17(H17)
;
_olex2_submission_special_instructions 'No special instructions were received'