A thiadiazole-fused N,N-dihydroquinoxaline: antiaromatic but isolable.
Miao, Shaobin; Schleyer, Paul v R; Wu, Judy I.; Hardcastle, Kenneth I.; Bunz, Uwe H. F.; Organic letters 9 (2007) 1073–1076; doi:10.1021/ol070013i

data_1505317
_publ_section_title
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 A thiadiazole-fused N,N-dihydroquinoxaline: antiaromatic but isolable.
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_journal_issue                   6
_journal_name_full               'Organic letters'
_journal_page_first              1073
_journal_page_last               1076
_journal_paper_doi               10.1021/ol070013i
_journal_volume                  9
_journal_year                    2007
_chemical_formula_sum            'C52 H83.5 N4 S Si4'
_chemical_formula_weight         909.15
_chemical_name_systematic
;

 ?

;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 93.664(5)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   55.844(4)
_cell_length_b                   13.8967(10)
_cell_length_c                   15.0754(10)
_cell_measurement_reflns_used    8139
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      42.91
_cell_measurement_theta_min      2.38
_cell_volume                     11675.3(14)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.892
_diffrn_measured_fraction_theta_max 0.892
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0550
_diffrn_reflns_av_sigmaI/netI    0.0839
_diffrn_reflns_limit_h_max       62
_diffrn_reflns_limit_h_min       -64
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            61529
_diffrn_reflns_theta_full        65.82
_diffrn_reflns_theta_max         65.82
_diffrn_reflns_theta_min         0.79
_exptl_absorpt_coefficient_mu    1.526
_exptl_absorpt_correction_T_max  0.8749
_exptl_absorpt_correction_T_min  0.4767
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS V2.10'
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.034
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             3964
_exptl_crystal_size_max          0.57
_exptl_crystal_size_mid          0.37
_exptl_crystal_size_min          0.09
_refine_diff_density_max         0.510
_refine_diff_density_min         -0.270
_refine_diff_density_rms         0.063
_refine_ls_extinction_coef       0.00054(7)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.024
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1181
_refine_ls_number_reflns         18063
_refine_ls_number_restraints     88
_refine_ls_restrained_S_all      1.023
_refine_ls_R_factor_all          0.1927
_refine_ls_R_factor_gt           0.1116
_refine_ls_shift/su_max          0.023
_refine_ls_shift/su_mean         0.003
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1700P)^2^+12.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2979
_refine_ls_wR_factor_ref         0.3541
_reflns_number_gt                8759
_reflns_number_total             18063
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol070013isi20070116_035912.cif
_cod_data_source_block           miao1s
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_original_formula_sum        'C52 H83.50 N4 S Si4'
_cod_database_code               1505317