Synthesis, crystal structure and theoretical studies of the first endo∶endo-2,4-diphosphabicyclo[1.1.0]butane
Jones, Cameron; Platts, Jamie A.; Richards, Anne F.; Chemical Communications  (2001) 663–; doi:10.1039/b100993l

data_7114769
_publ_section_title
;
 Synthesis, crystal structure and theoretical studies of the first
 endo&#x2236;endo-2,4-diphosphabicyclo[1.1.0]butane
;
_journal_issue                   7
_journal_name_full               'Chemical Communications'
_journal_page_first              663
_journal_paper_doi               10.1039/b100993l
_journal_year                    2001
_chemical_formula_sum            'C22 H40 P2'
_chemical_formula_weight         366.48
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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            4
_cell_length_a                   9.945(2)
_cell_length_b                   14.071(3)
_cell_length_c                   16.065(3)
_cell_measurement_temperature    150(2)
_cell_volume                     2248.1(8)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_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  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0192
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       0
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            2303
_diffrn_reflns_theta_full        25.19
_diffrn_reflns_theta_max         25.19
_diffrn_reflns_theta_min         2.41
_exptl_absorpt_coefficient_mu    0.195
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.083
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             808
_exptl_crystal_size_max          0.5
_exptl_crystal_size_mid          0.5
_exptl_crystal_size_min          0.4
_refine_diff_density_max         0.454
_refine_diff_density_min         -0.366
_refine_diff_density_rms         0.084
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.15(15)
_refine_ls_extinction_coef       0.024(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   1.076
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     225
_refine_ls_number_reflns         2303
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.076
_refine_ls_R_factor_all          0.0466
_refine_ls_R_factor_gt           0.0417
_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^)+(0.1127P)^2^+0.1900P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1223
_refine_ls_wR_factor_ref         0.1344
_reflns_number_gt                2146
_reflns_number_total             2303
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b100993l.txt
_cod_data_source_block           compound_3
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               7114769