Conformationally Constrained, Stable, Triplet Ground State (S=1) Nitroxide Diradicals. Antiferromagnetic Chains of S=1 Diradicals
Andrzej Rajca; Masahiro Takahashi; Maren Pink; Gaëlle Spagnol; Suchada Rajca; Journal of the American Chemical Society 129 (2007) 10159–10170; doi:10.1021/ja0712017

data_4109779
_publ_section_title
;
 Conformationally Constrained, Stable, Triplet Ground State (S=1)
 Nitroxide Diradicals. Antiferromagnetic Chains of S=1 Diradicals
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              10159
_journal_page_last               10170
_journal_paper_doi               10.1021/ja0712017
_journal_volume                  129
_journal_year                    2007
_chemical_formula_moiety         'C18 H26 N2 O4'
_chemical_formula_sum            'C18 H26 N2 O4'
_chemical_formula_weight         334.41
_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                 92.679(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.7862(9)
_cell_length_b                   8.0998(8)
_cell_length_c                   24.100(2)
_cell_measurement_reflns_used    5344
_cell_measurement_temperature    130(2)
_cell_measurement_theta_max      26.4
_cell_measurement_theta_min      2.3
_cell_volume                     1713.2(3)
_computing_cell_refinement       'SAINT (Bruker, 2003)'
_computing_data_collection       'SMART (Bruker, 2001)'
_computing_data_reduction        'SAINT (Bruker, 2003)'
_computing_molecular_graphics    'SHELXTL (Bruker, 2003), XTEL (loc. libr.)'
_computing_publication_material  'SHELXTL (Bruker, 2003)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR-2004 (Burla et al., 2005)'
_diffrn_ambient_temperature      130(2)
_diffrn_detector                 'CCD area detector'
_diffrn_detector_area_resol_mean 44.52
_diffrn_detector_type            'Bruker SMART 6000'
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_details
'0.30 degree frames measured for 20 seconds each'
_diffrn_measurement_device       'three-circle goniometer with fixed chi'
_diffrn_measurement_device_type  'Bruker Platform goniometer'
_diffrn_measurement_method       \w-scans
_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  0.0436
_diffrn_reflns_av_sigmaI/netI    0.0262
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       -30
_diffrn_reflns_number            23186
_diffrn_reflns_theta_full        26.40
_diffrn_reflns_theta_max         26.40
_diffrn_reflns_theta_min         1.69
_diffrn_standards_decay_%        0.0
_diffrn_standards_interval_time  808
_diffrn_standards_number         89
_exptl_absorpt_coefficient_mu    0.092
_exptl_absorpt_correction_T_max  0.9828
_exptl_absorpt_correction_T_min  0.9801
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS, R. Blessing; 1995'
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.297
_exptl_crystal_description       block
_exptl_crystal_F_000             720
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.19
_refine_diff_density_max         0.234
_refine_diff_density_min         -0.254
_refine_diff_density_rms         0.060
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.030
_refine_ls_hydrogen_treatment    riding
_refine_ls_matrix_type           full
_refine_ls_number_parameters     251
_refine_ls_number_reflns         3489
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.030
_refine_ls_R_factor_all          0.0470
_refine_ls_R_factor_gt           0.0368
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0485P)^2^+0.7821P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0922
_refine_ls_wR_factor_ref         0.1031
_reflns_number_gt                2880
_reflns_number_total             3489
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja0712017si20070219_032012.cif
_cod_data_source_block           06475
_cod_database_code               4109779