Heterodimetallic Alkaline Earth Metal Amides: Synthesis, Structure, and Solvent-Induced Charge Separation of Homoleptic Calcium−Magnesium Hexamethyldisilazide
Wendell, Lauren T.; Bender, John; He, Xuyang; Noll, Bruce C.; Henderson, Kenneth W.; Organometallics 25 (2006) 4953–; doi:10.1021/om060521g

data_4074291
_publ_section_title
;
 Heterodimetallic Alkaline Earth Metal Amides:&#x00A0; Synthesis,
 Structure, and Solvent-Induced Charge Separation of Homoleptic
 Calcium&#x2212;Magnesium Hexamethyldisilazide
;
_journal_issue                   21
_journal_name_full               Organometallics
_journal_page_first              4953
_journal_paper_doi               10.1021/om060521g
_journal_volume                  25
_journal_year                    2006
_chemical_compound_source        synthesized
_chemical_formula_moiety         'C24 H72 Ca Mg N4 Si8'
_chemical_formula_sum            'C24 H72 Ca Mg N4 Si8'
_chemical_formula_weight         705.97
_chemical_melting_point          396
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_Int_Tables_number      2
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                87.541(2)
_cell_angle_beta                 85.780(3)
_cell_angle_gamma                69.550(2)
_cell_formula_units_Z            2
_cell_length_a                   9.1640(3)
_cell_length_b                   12.1080(4)
_cell_length_c                   21.6540(8)
_cell_measurement_reflns_used    3329
_cell_measurement_temperature    220(2)
_cell_measurement_theta_max      26.2851
_cell_measurement_theta_min      2.3766
_cell_volume                     2244.77(14)
_computing_cell_refinement       'APEX2/SAINT (Bruker, 2004)'
_computing_data_collection       'APEX2 (Bruker, 2004)'
_computing_data_reduction        'SAINT/XPREP (Bruker, 2004; Sheldrick, 2003)'
_computing_molecular_graphics    'XP (Sheldrick, 1998)'
_computing_publication_material  'XCIF (Sheldrick, 2001)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      220(2)
_diffrn_detector_area_resol_mean 8.33
_diffrn_measured_fraction_theta_full 0.934
_diffrn_measured_fraction_theta_max 0.934
_diffrn_measurement_device_type  'Bruker SMART APEX CCD diffractometer'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0255
_diffrn_reflns_av_sigmaI/netI    0.0599
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            12520
_diffrn_reflns_theta_full        26.35
_diffrn_reflns_theta_max         26.35
_diffrn_reflns_theta_min         1.89
_diffrn_source                   'fine-focus sealed tube'
_diffrn_source_type              'Siemans KFFMO2K-90'
_exptl_absorpt_coefficient_mu    0.386
_exptl_absorpt_correction_T_max  0.9106
_exptl_absorpt_correction_T_min  0.8851
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'Blessing, R.H. (1995) Acta Cryst. A51, 33-38.'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.044
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             776
_exptl_crystal_recrystallization_method
'dissolved in toluene, reduced volume, added hexanes, filtered, cooled to 253K'
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.31
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.365
_refine_diff_density_min         -0.353
_refine_diff_density_rms         0.061
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.055
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     407
_refine_ls_number_reflns         8562
_refine_ls_number_restraints     43
_refine_ls_restrained_S_all      1.063
_refine_ls_R_factor_all          0.0853
_refine_ls_R_factor_gt           0.0544
_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^)+(0.0442P)^2^+1.7299P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1102
_refine_ls_wR_factor_ref         0.1243
_reflns_number_gt                6106
_reflns_number_total             8562
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            om060521gsi20060614_121210.cif
_cod_data_source_block           lw12dis
_cod_original_cell_volume        2244.77(13)
_cod_database_code               4074291