Mechanisms of Exchange Modulation in Trimethylenemethane-type Biradicals: The Roles of Conformation and Spin Density
David A. Shultz; Rosario M. Fico; Hyoyoung Lee; Jeff W. Kampf; Kristin Kirschbaum; A. Alan Pinkerton; Paul D. Boyle; Journal of the American Chemical Society 125 (2003) 15426–15432; doi:10.1021/ja037787o

data_4114491
_publ_contact_author
;
        David A. Shultz
    Department of Chemistry, 527 Dabney Hall
    North Carolina State University
    Raleigh, NC  27695-8204
;
_publ_contact_author_email       David_Shultz@ncsu.edu
_publ_contact_author_fax         (919)515-6972
_publ_contact_author_phone       (919)515-8920
_publ_section_title
;
 Mechanisms of Exchange Modulation in Trimethylenemethane-type Biradicals:
 The Roles of Conformation and Spin Density
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              15426
_journal_page_last               15432
_journal_paper_doi               10.1021/ja037787o
_journal_volume                  125
_journal_year                    2003
_chemical_formula_sum            'C28 H36 N2 O2'
_chemical_formula_weight         432.59
_space_group_IT_number           13
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yc'
_symmetry_space_group_name_H-M   'P 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                 94.592(5)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   15.034(2)
_cell_length_b                   8.4086(11)
_cell_length_c                   19.420(3)
_cell_measurement_reflns_used    910
_cell_measurement_temperature    158(2)
_cell_measurement_theta_max      20.96
_cell_measurement_theta_min      2.42
_cell_volume                     2447.1(6)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'Bruker SHELXTL'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      158(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0406
_diffrn_reflns_av_sigmaI/netI    0.0861
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            28025
_diffrn_reflns_theta_full        23.25
_diffrn_reflns_theta_max         23.25
_diffrn_reflns_theta_min         2.10
_exptl_absorpt_coefficient_mu    0.073
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            brown
_exptl_crystal_density_diffrn    1.174
_exptl_crystal_description       plate
_exptl_crystal_F_000             936
_exptl_crystal_size_max          0.06
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.24
_refine_diff_density_max         0.323
_refine_diff_density_min         -0.264
_refine_diff_density_rms         0.071
_refine_ls_extinction_coef       0.038(3)
_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   0.983
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     301
_refine_ls_number_reflns         3524
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.983
_refine_ls_R_factor_all          0.1185
_refine_ls_R_factor_gt           0.0584
_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^)+(0.0919P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1330
_refine_ls_wR_factor_ref         0.1642
_reflns_number_gt                2083
_reflns_number_total             3524
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja037787orom20030718_030736.cif
_cod_data_source_block           flat2
_cod_database_code               4114491