Intermetallic Lithium-Magnesium Hexamethyldisilazide: Synthesis and Structure, Discovery of an Oxygen-Centered Variant, and a Reaction with Benzonitrile That Produces a Novel Amidinate Cage Compound with a Trigonal Bipyramidal Li4MgO Core
Alan R. Kennedy; Robert E. Mulvey; René B. Rowlings; Journal of the American Chemical Society 120 (1998) 7816–7824; doi:10.1021/ja980561e

data_4116798
_publ_section_title
;
 Intermetallic Lithium-Magnesium Hexamethyldisilazide: Synthesis and
 Structure, Discovery of an Oxygen-Centered Variant, and a Reaction with
 Benzonitrile That Produces a Novel Amidinate Cage Compound with a
 Trigonal Bipyramidal Li4MgO Core
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              7816
_journal_page_last               7824
_journal_paper_doi               10.1021/ja980561e
_journal_volume                  120
_journal_year                    1998
_chemical_formula_sum            'C52 H92 Li4 Mg N8 O Si8'
_chemical_formula_weight         1122.13
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           60
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2n 2ab'
_symmetry_space_group_name_H-M   'P b c n'
_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                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.317(3)
_cell_length_b                   26.138(15)
_cell_length_c                   24.986(14)
_cell_measurement_reflns_used    17
_cell_measurement_temperature    123
_cell_measurement_theta_max      8.0
_cell_measurement_theta_min      6.7
_cell_volume                     6738(6)
_computing_cell_refinement       '"'
_computing_data_collection       'MSC Diffractometer Control'
_computing_data_reduction        Texsan
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    SIR92
_diffrn_ambient_temperature      123
_diffrn_measured_fraction_theta_full 0.899
_diffrn_measured_fraction_theta_max 0.899
_diffrn_measurement_device_type  'Rigaku AFC7S'
_diffrn_measurement_method       \w/2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.2477
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       31
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       0
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            5945
_diffrn_reflns_theta_full        25.01
_diffrn_reflns_theta_max         25.01
_diffrn_reflns_theta_min         2.56
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 150
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.208
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.106
_exptl_crystal_description       'cut needle'
_exptl_crystal_F_000             2416
_exptl_crystal_size_max          0.60
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.371
_refine_diff_density_min         -0.503
_refine_diff_density_rms         0.072
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.956
_refine_ls_hydrogen_treatment    calc
_refine_ls_matrix_type           full
_refine_ls_number_parameters     348
_refine_ls_number_reflns         5945
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.956
_refine_ls_R_factor_all          0.2415
_refine_ls_R_factor_gt           0.0571
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0672P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1326
_refine_ls_wR_factor_ref         0.1783
_reflns_number_gt                2300
_reflns_number_total             5945
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ja980561e_3.cif
_cod_data_source_block           li4mg
_cod_depositor_comments
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The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0672P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.0672P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_database_code               4116798