Formazans as beta-diketiminate analogues. Structural characterization of boratatetrazines and their reduction to borataverdazyl radical anions.
Gilroy, Joe B; Ferguson, Michael J; McDonald, Robert; Patrick, Brian O; Hicks, Robin G; Chemical communications (Cambridge, England)  (2006) 126–128; doi:10.1039/b609365e

data_7101629
_publ_section_title
;
 Formazans as beta-diketiminate analogues. Structural characterization
 of boratatetrazines and their reduction to borataverdazyl radical
 anions.
;
_journal_issue                   2
_journal_name_full
'Chemical communications (Cambridge, England)'
_journal_page_first              126
_journal_page_last               128
_journal_paper_doi               10.1039/b609365e
_journal_year                    2006
_chemical_formula_sum            'C21 H20 N4'
_chemical_formula_weight         328.41
_chemical_name_systematic
;
?
;
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   7.8300(10)
_cell_length_b                   21.154(2)
_cell_length_c                   22.289(3)
_cell_measurement_reflns_used    1626
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      21.55
_cell_measurement_theta_min      2.92
_cell_volume                     3691.9(8)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.989
_diffrn_measured_fraction_theta_max 0.989
_diffrn_measurement_device_type  'Bruker X8 APEX'
_diffrn_measurement_method       'area detector'
_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  0.0553
_diffrn_reflns_av_sigmaI/netI    0.0707
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            9155
_diffrn_reflns_theta_full        22.62
_diffrn_reflns_theta_max         22.62
_diffrn_reflns_theta_min         1.83
_exptl_absorpt_coefficient_mu    0.072
_exptl_absorpt_correction_T_max  0.993
_exptl_absorpt_correction_T_min  0.588
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.182
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             1392
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.248
_refine_diff_density_min         -0.182
_refine_diff_density_rms         0.039
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.004
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     230
_refine_ls_number_reflns         2431
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.004
_refine_ls_R_factor_all          0.1413
_refine_ls_R_factor_gt           0.0576
_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^)+(0.0751P)^2^+1.5572P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1341
_refine_ls_wR_factor_ref         0.1788
_reflns_number_gt                1194
_reflns_number_total             2431
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b609365e.txt
_cod_data_source_block           rh003
_cod_original_sg_symbol_H-M      'P bca'
_cod_database_code               7101629