Spontaneous Generation of Stable Pnictinyl Radicals from "Jack-in-the-Box" Dipnictines: A Solid-State, Gas-Phase, and Theoretical Investigation of the Origins of Steric Stabilization1
Sarah L. Hinchley; Carole A. Morrison; David W. H. Rankin; Charles L. B. Macdonald; Robert J. Wiacek; Andreas Voigt; Alan H. Cowley; Michael F. Lappert; Grete Gundersen; Jason A. C. Clyburne; Philip P. Power; Journal of the American Chemical Society 123 (2001) 9045–9053; doi:10.1021/ja010615b

data_4115689
_publ_section_title
;
 Spontaneous Generation of Stable Pnictinyl Radicals from
 "Jack-in-the-Box" Dipnictines: A Solid-State, Gas-Phase, and Theoretical
 Investigation of the Origins of Steric Stabilization1
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              9045
_journal_page_last               9053
_journal_paper_doi               10.1021/ja010615b
_journal_volume                  123
_journal_year                    2001
_chemical_compound_source        selfmade
_chemical_formula_moiety         'C28 H76 P2 Si8'
_chemical_formula_structural     '[((CH3)3Si)2)CH)2P]2'
_chemical_formula_sum            'C28 H76 P2 Si8'
_chemical_formula_weight         699.55
_chemical_name_common            tetra(disyl)diphosphine
_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
_cell_angle_alpha                90.00
_cell_angle_beta                 110.650(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   18.341(2)
_cell_length_b                   13.4240(10)
_cell_length_c                   19.033(2)
_cell_measurement_reflns_used    55
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      12.49
_cell_measurement_theta_min      4.58
_cell_volume                     4385.0(8)
_computing_cell_refinement       'Siemens XSCANS'
_computing_data_collection       'Siemens XSCANS'
_computing_data_reduction        'Siemens SHELXTL'
_computing_molecular_graphics    'Siemens SHELXTL'
_computing_publication_material  'Siemens SHELXTL'
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measurement_device       'Siemens P4'
_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  0.0173
_diffrn_reflns_av_sigmaI/netI    0.0184
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -2
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            9263
_diffrn_reflns_theta_max         25.06
_diffrn_reflns_theta_min         1.19
_diffrn_standards_decay_%        7.85
_diffrn_standards_interval_count 97
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.335
_exptl_absorpt_correction_T_max  0.7984
_exptl_absorpt_correction_T_min  0.7332
_exptl_absorpt_correction_type   integration
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.060
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    none
_exptl_crystal_description       blocks
_exptl_crystal_F_000             1544
_exptl_crystal_size_max          0.53
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.35
_refine_diff_density_max         0.281
_refine_diff_density_min         -0.241
_refine_diff_density_rms         0.051
_refine_ls_extinction_coef       0.0033(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_all   1.089
_refine_ls_goodness_of_fit_obs   1.109
_refine_ls_matrix_type           full
_refine_ls_number_parameters     360
_refine_ls_number_reflns         7702
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.100
_refine_ls_restrained_S_obs      1.109
_refine_ls_R_factor_all          0.0435
_refine_ls_R_factor_obs          0.0360
_refine_ls_shift/esd_max         0.037
_refine_ls_shift/esd_mean        0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0489P)^2^+2.7001P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1025
_refine_ls_wR_factor_obs         0.0958
_reflns_number_observed          6659
_reflns_number_total             7709
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            ja010615b_3.cif
_cod_data_source_block           renum
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'none' 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 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0489P)^2^+2.7001P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.0489P)^2^+2.7001P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        4385.0(7)
_cod_database_code               4115689