Homoleptic tris(methoxydimethylsilyl)silanides of the alkaline earth metals: first zwitterionic silanides with two naked silyl anions
Bryan Carlson; Adelia J. A. Aquino; Louisa J. Hope-Weeks; Bruce Whittlesey; Brian McNerney; William L. Hase; Clemens Krempner; Chem.Commun. 47 (2011) 11089–; doi:10.1039/c1cc13933a

data_7106909
_publ_section_title
;
 Homoleptic tris(methoxydimethylsilyl)silanides of the alkaline earth
 metals: first zwitterionic silanides with two naked silyl anions
;
_journal_name_full               Chem.Commun.
_journal_page_first              11089
_journal_paper_doi               10.1039/c1cc13933a
_journal_volume                  47
_journal_year                    2011
_chemical_formula_sum            'C18 H54 Mg O6 Si8'
_chemical_formula_weight         615.64
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 95.4620(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   9.8056(10)
_cell_length_b                   12.7931(13)
_cell_length_c                   13.7123(14)
_cell_measurement_reflns_used    1967
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      21.50
_cell_measurement_theta_min      2.18
_cell_volume                     1712.3(3)
_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      150(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \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  0.0713
_diffrn_reflns_av_sigmaI/netI    0.0500
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            15332
_diffrn_reflns_theta_full        24.08
_diffrn_reflns_theta_max         24.08
_diffrn_reflns_theta_min         2.18
_exptl_absorpt_coefficient_mu    0.360
_exptl_absorpt_correction_T_max  0.9537
_exptl_absorpt_correction_T_min  0.9381
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.194
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block/needle
_exptl_crystal_F_000             668
_exptl_crystal_size_max          0.18
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.13
_refine_diff_density_max         0.301
_refine_diff_density_min         -0.223
_refine_diff_density_rms         0.058
_refine_ls_extinction_coef       0.0006(4)
_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   1.043
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     161
_refine_ls_number_reflns         2727
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.043
_refine_ls_R_factor_all          0.0619
_refine_ls_R_factor_gt           0.0379
_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^)+(0.0232P)^2^+1.3161P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0735
_refine_ls_wR_factor_ref         0.0820
_reflns_number_gt                2041
_reflns_number_total             2727
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c1cc13933a.txt
_cod_data_source_block           ljhw_krempner_9_0m
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' 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 
;
_cod_original_sg_symbol_H-M      P2(1)/n
_cod_database_code               7106909