An Ylide-like Phosphasilene and Striking Formation of a 4π-Electron, Resonance-Stabilized 2,4-Disila-1,3-diphosphacyclobutadiene
Shigeyoshi Inoue; Wenyuan, Wang; Carsten Präsang; Matthew Asay; Elisabeth Irran; Matthias Driess; Journal of the American Chemical Society 133 (2011) 2868–2871; doi:10.1021/ja200462y

data_4105719
_publ_section_title
;
 An Ylide-like Phosphasilene and Striking Formation of a 4\p-Electron,
 Resonance-Stabilized 2,4-Disila-1,3-diphosphacyclobutadiene
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              2868
_journal_page_last               2871
_journal_paper_doi               10.1021/ja200462y
_journal_volume                  133
_journal_year                    2011
_chemical_formula_sum            'C44 H60 N4 P2 Si2'
_chemical_formula_weight         763.08
_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
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.66 (release 28-04-2010 CrysAlis171 .NET)
(compiled Apr 28 2010,14:27:37)
;
_cell_angle_alpha                90.00
_cell_angle_beta                 108.346(12)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   23.841(3)
_cell_length_b                   10.1993(12)
_cell_length_c                   19.369(2)
_cell_measurement_reflns_used    5280
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      32.4762
_cell_measurement_theta_min      3.4114
_cell_volume                     4470.4(10)
_computing_cell_refinement
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.66 (release 28-04-2010 CrysAlis171 .NET)
(compiled Apr 28 2010,14:27:37)
;
_computing_data_collection
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.66 (release 28-04-2010 CrysAlis171 .NET)
(compiled Apr 28 2010,14:27:37)
;
_computing_data_reduction
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.66 (release 28-04-2010 CrysAlis171 .NET)
(compiled Apr 28 2010,14:27:37)
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Xcalibur, Sapphire3'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Enhance (Mo) X-ray Source'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0447
_diffrn_reflns_av_sigmaI/netI    0.0425
_diffrn_reflns_limit_h_max       28
_diffrn_reflns_limit_h_min       -28
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            16197
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         3.53
_exptl_absorpt_coefficient_mu    0.184
_exptl_absorpt_correction_T_max  0.9053
_exptl_absorpt_correction_T_min  0.8725
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.66 (release 28-04-2010 CrysAlis171 .NET)
(compiled Apr 28 2010,14:27:37)
empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.134
_exptl_crystal_description       block
_exptl_crystal_F_000             1640
_exptl_crystal_size_max          0.76
_exptl_crystal_size_mid          0.57
_exptl_crystal_size_min          0.55
_refine_diff_density_max         0.721
_refine_diff_density_min         -0.649
_refine_diff_density_rms         0.059
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.034
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     251
_refine_ls_number_reflns         3927
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.034
_refine_ls_R_factor_all          0.0843
_refine_ls_R_factor_gt           0.0618
_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^)+(0.0624P)^2^+11.9081P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1393
_refine_ls_wR_factor_ref         0.1489
_reflns_number_gt                3082
_reflns_number_total             3927
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja200462y_si_004.cif
_cod_data_source_block           c2c
_cod_original_cell_volume        4470.3(9)
_cod_database_code               4105719