Bistable Polymorphs Showing Diamagnetic and Paramagnetic States of an Organic Crystalline Biradical Biphenyl-3,5-diyl Bis(tert-butylnitroxide)
Nishimaki, Hirokazu; Mashiyama, Shinichiro; Yasui, Masanori; Nogami, Takashi; Ishida, Takayuki; Chemistry of Materials 18 (2006) 3602–; doi:10.1021/cm061222k

data_4001581
_publ_section_title
;
 Bistable Polymorphs Showing Diamagnetic and Paramagnetic States of an
 Organic Crystalline Biradical Biphenyl-3,5-diyl Bis(tert-butylnitroxide)
;
_journal_issue                   16
_journal_name_full               'Chemistry of Materials'
_journal_page_first              3602
_journal_paper_doi               10.1021/cm061222k
_journal_volume                  18
_journal_year                    2006
_chemical_formula_moiety         'C20 H26 N2 O2'
_chemical_formula_sum            'C20 H26 N2 O2'
_chemical_formula_weight         326.43
_chemical_melting_point          136
_chemical_name_common            'beta-phase BPBN'
_chemical_name_systematic
; 
 biphenyl-3,5-diyl bis(tert-butyl nitroxide) 
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/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                 110.548(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   29.2720(19)
_cell_length_b                   11.7396(7)
_cell_length_c                   11.2259(7)
_cell_measurement_reflns_used    4140
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      27.20
_cell_measurement_theta_min      3.94
_cell_volume                     3612.3(4)
_computing_cell_refinement       PROCESS-AUTO(1998)
_computing_data_collection       PROCESS-AUTO(1998)
_computing_data_reduction        PROCESS-AUTO(1998)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 0.1
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Rigaku R-AXIS Rapid'
_diffrn_measurement_method       'omega 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  0.0511
_diffrn_reflns_av_sigmaI/netI    0.0353
_diffrn_reflns_limit_h_max       38
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            4141
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         3.47
_exptl_absorpt_coefficient_mu    0.078
_exptl_absorpt_correction_T_max  0.980736
_exptl_absorpt_correction_T_min  0.974042
_exptl_absorpt_correction_type   numerical
_exptl_crystal_colour            brown
_exptl_crystal_density_diffrn    1.200
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1408
_exptl_crystal_size_max          0.45
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.354
_refine_diff_density_min         -0.171
_refine_diff_density_rms         0.038
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.054
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     322
_refine_ls_number_reflns         4141
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.054
_refine_ls_R_factor_all          0.0438
_refine_ls_R_factor_gt           0.0358
_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^)+(0.0584P)^2^+0.2699P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0980
_refine_ls_wR_factor_ref         0.1001
_reflns_number_gt                3341
_reflns_number_total             4141
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            cm061222ksi20060524_105941.cif
_cod_data_source_block           '_beta-BPBN'
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               4001581