Which isomer is it, 1,2,5,6- or 1,4,5,8-tetrasubstituted cycloocta-1,3,5,7-tetraene? Synthesis of symmetrically tetrasubstituted cycloocta-1,3,5,7-tetraene derivatives
Gadigennavar, Savita; Ranganathan, Madhav; Sankararaman, Sethuraman; Organic & Biomolecular Chemistry 18 (2020) 9284–9291; doi:10.1039/D0OB01871F

data_7157792
_publ_section_title
;
 Which isomer is it, 1,2,5,6- or 1,4,5,8-tetrasubstituted
 cycloocta-1,3,5,7-tetraene? Synthesis of symmetrically tetrasubstituted
 cycloocta-1,3,5,7-tetraene derivatives
;
_journal_issue                   45
_journal_name_full               'Organic &amp; Biomolecular Chemistry'
_journal_page_first              9284
_journal_page_last               9291
_journal_paper_doi               10.1039/D0OB01871F
_journal_volume                  18
_journal_year                    2020
_chemical_formula_moiety         'C44 H36 N12'
_chemical_formula_sum            'C44 H36 N12'
_chemical_formula_weight         732.85
_space_group_crystal_system      monoclinic
_space_group_IT_number           15
_space_group_name_Hall           '-C 2yc'
_space_group_name_H-M_alt        'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2020-08-15 deposited with the CCDC.	2020-10-22 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 116.4550(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   23.8429(11)
_cell_length_b                   14.4588(7)
_cell_length_c                   12.0020(5)
_cell_measurement_reflns_used    9946
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      26.38
_cell_measurement_theta_min      2.99
_cell_volume                     3704.3(3)
_computing_cell_refinement       'APEX3/SAINT (Bruker, 2016)'
_computing_data_collection       'APEX3(Bruker, 2016)'
_computing_data_reduction        'SAINT/XPREP (Bruker, 2016)'
_computing_molecular_graphics
'ORTEP3 (Farrugia, 1997) and Mercury (Bruno et al., 2002)'
_computing_publication_material  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXT-2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker axs kappa apex3 CMOS Diffractometer'
_diffrn_measurement_method       '\w and \f scan'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0415
_diffrn_reflns_av_unetI/netI     0.0232
_diffrn_reflns_Laue_measured_fraction_full 0.996
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       29
_diffrn_reflns_limit_h_min       -29
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            36006
_diffrn_reflns_point_group_measured_fraction_full 0.996
_diffrn_reflns_point_group_measured_fraction_max 0.997
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.997
_diffrn_reflns_theta_min         3.191
_exptl_absorpt_coefficient_mu    0.082
_exptl_absorpt_correction_T_max  0.7458
_exptl_absorpt_correction_T_min  0.7022
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Bruker, 2016)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.314
_exptl_crystal_description       block
_exptl_crystal_F_000             1536
_exptl_crystal_size_max          0.300
_exptl_crystal_size_mid          0.250
_exptl_crystal_size_min          0.200
_refine_diff_density_max         0.162
_refine_diff_density_min         -0.195
_refine_diff_density_rms         0.039
_refine_ls_extinction_coef       0.0114(11)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2014/7 (Sheldrick 2014'
_refine_ls_goodness_of_fit_ref   1.081
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     254
_refine_ls_number_reflns         3632
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.081
_refine_ls_R_factor_all          0.0810
_refine_ls_R_factor_gt           0.0494
_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^)+(0.0543P)^2^+2.8486P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1170
_refine_ls_wR_factor_ref         0.1456
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2505
_reflns_number_total             3632
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d0ob01871f2.cif
_cod_data_source_block           COT
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               7157792
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.976
_shelx_estimated_absorpt_t_max   0.984
_shelx_res_checksum              60089