N-Heterocyclic carbene stabilized adducts of alkyl magnesium amide, bisalkyl magnesium and Grignard reagents: trapping oligomeric organo s-block fragments with NHCs.
Kennedy, Alan R.; Mulvey, Robert E.; Robertson, Stuart D.; Dalton transactions (Cambridge, England : 2003) 39 (2010) 9091–9099; doi:10.1039/c0dt00693a

data_7026769
_publ_section_title
;
 N-Heterocyclic carbene stabilized adducts of alkyl magnesium amide,
 bisalkyl magnesium and Grignard reagents: trapping oligomeric organo
 s-block fragments with NHCs.
;
_journal_issue                   38
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              9091
_journal_page_last               9099
_journal_paper_doi               10.1039/c0dt00693a
_journal_volume                  39
_journal_year                    2010
_chemical_formula_moiety         'C20 H54 Mg2 N2 Si4'
_chemical_formula_sum            'C20 H54 Mg2 N2 Si4'
_chemical_formula_weight         483.63
_chemical_name_systematic
;
?
;
_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           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 92.001(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   16.3833(5)
_cell_length_b                   11.1092(3)
_cell_length_c                   17.1805(5)
_cell_measurement_reflns_used    7374
_cell_measurement_temperature    123(2)
_cell_measurement_theta_max      30.2143
_cell_measurement_theta_min      3.2084
_cell_volume                     3125.04(16)
_computing_cell_refinement
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET)
(compiled Jan 5 2010,16:28:46)
;
_computing_data_collection
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET)
(compiled Jan 5 2010,16:28:46)
;
_computing_data_reduction
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET)
(compiled Jan 5 2010,16:28:46)
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      123(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.911
_diffrn_measurement_device_type  'Oxford Diffraction Xcalibur, Eos'
_diffrn_measurement_method       '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  0.0264
_diffrn_reflns_av_sigmaI/netI    0.0325
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -22
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            11966
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         30.28
_diffrn_reflns_theta_min         3.21
_exptl_absorpt_coefficient_mu    0.240
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.85798
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET)
(compiled Jan 5 2010,16:28:46)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.028
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1072
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.694
_refine_diff_density_min         -0.268
_refine_diff_density_rms         0.062
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.075
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     143
_refine_ls_number_reflns         4261
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.075
_refine_ls_R_factor_all          0.0587
_refine_ls_R_factor_gt           0.0466
_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^)+(0.0565P)^2^+3.5350P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1183
_refine_ls_wR_factor_ref         0.1224
_reflns_number_gt                3413
_reflns_number_total             4261
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c0dt00693a.txt
_cod_data_source_block           nBuMgHMDS
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               7026769