Donor-Stabilized Silacyclobutanone: A Precursor of 1-Silaketene via Retro-[2 + 2]-Cycloaddition Reaction at Room Temperature.
Troadec, Thibault; Lopez Reyes, Morelia; Rodriguez, Ricardo; Baceiredo, Antoine; Saffon-Merceron, Nathalie; Branchadell, Vicenç; Kato, Tsuyoshi; Journal of the American Chemical Society 138 (2016) 2965–2968; doi:10.1021/jacs.6b00631

data_4124932
_publ_section_title
;
 Donor-Stabilized Silacyclobutanone: A Precursor of 1-Silaketene via
 Retro-[2 + 2]-Cycloaddition Reaction at Room Temperature.
;
_journal_issue                   9
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              2965
_journal_page_last               2968
_journal_paper_doi               10.1021/jacs.6b00631
_journal_volume                  138
_journal_year                    2016
_chemical_absolute_configuration ad
_chemical_formula_sum            'C84 H132 N6 O5 P2 Si4'
_chemical_formula_weight         1480.26
_space_group_IT_number           152
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  'P 31 2"'
_symmetry_space_group_name_H-M   'P 31 2 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                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            3
_cell_length_a                   15.3555(15)
_cell_length_b                   15.3555(15)
_cell_length_c                   30.769(3)
_cell_measurement_reflns_used    9304
_cell_measurement_temperature    193(2)
_cell_measurement_theta_max      25.71
_cell_measurement_theta_min      2.51
_cell_volume                     6283.1(11)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      193(2)
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device_type  'Bruker kappa APEX-II CCD Quazar'
_diffrn_measurement_method       'phi and omega 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  0.1285
_diffrn_reflns_av_sigmaI/netI    0.0504
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       41
_diffrn_reflns_limit_l_min       -39
_diffrn_reflns_number            198846
_diffrn_reflns_theta_full        28.27
_diffrn_reflns_theta_max         28.27
_diffrn_reflns_theta_min         5.24
_exptl_absorpt_coefficient_mu    0.162
_exptl_absorpt_correction_T_max  0.9531
_exptl_absorpt_correction_T_min  0.9235
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Bruker-AXS)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.174
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             2412
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.267
_refine_diff_density_min         -0.381
_refine_diff_density_rms         0.058
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.0(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.066
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     602
_refine_ls_number_reflns         10327
_refine_ls_number_restraints     415
_refine_ls_restrained_S_all      1.049
_refine_ls_R_factor_all          0.0809
_refine_ls_R_factor_gt           0.0660
_refine_ls_shift/su_max          0.011
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0529P)^2^+8.1172P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1561
_refine_ls_wR_factor_ref         0.1649
_reflns_number_gt                8737
_reflns_number_total             10327
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja6b00631_si_002.cif
_cod_data_source_block           3
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Trigonal' changed to 'trigonal'
according to
/usr/data/users/saulius/crontab/automatic-downloads/rss-feeds/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 4268 2015-11-12 08:31:59Z antanas 

 Adding full bibliography for 4124930--4124933.cif.
;
_cod_original_cell_volume        6283.0(11)
_cod_original_sg_symbol_H-M      P3(1)21
_cod_database_code               4124932