Tris(triorganosilyl)methyl derivatives of potassium and lithium bearing dimethylamino or methoxy substituents at silicon. Crystal structures of KC(SiMe3)2(SiMe2NMe2), KC(SiMe2NMe2)3 and [LiC(SiMe3)(SiMe2OMe)2]2
Al-Juaid, Salih S.; Eaborn, Colin; El-Hamruni, Salima; Farook, Adam; Hitchcock, Peter B.; Hopman, Martijn; Smith, J. David; Clegg, William; Izod, Keith; O’Shaughnessy, Paul; Journal of the Chemical Society, Dalton Transactions  (1999) 3267–; doi:10.1039/a904043i

data_7027564
_publ_section_title
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 Tris(triorganosilyl)methyl derivatives of potassium and lithium bearing
 dimethylamino or methoxy substituents at silicon. Crystal structures of
 KC(SiMe3)2(SiMe2NMe2), KC(SiMe2NMe2)3 and [LiC(SiMe3)(SiMe2OMe)2]2
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_journal_issue                   18
_journal_name_full
'Journal of the Chemical Society, Dalton Transactions'
_journal_page_first              3267
_journal_paper_doi               10.1039/a904043i
_journal_year                    1999
_chemical_formula_structural     '[{Li(C(SiMe3)(SiMe2OMe)2}2]'
_chemical_formula_sum            'C20 H54 Li2 O4 Si6'
_chemical_formula_weight         541.05
_chemical_name_systematic
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 ? 
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_space_group_IT_number           64
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-C 2ac 2'
_symmetry_space_group_name_H-M   'C m c a'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   15.569(3)
_cell_length_b                   12.603(2)
_cell_length_c                   16.848(2)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      10
_cell_measurement_theta_min      7
_cell_volume                     3305.8(9)
_computing_cell_refinement       'Enraf-Nonius CAD4'
_computing_data_collection       'Enraf-Nonius CAD4'
_computing_molecular_graphics    'CAMERON (Watkin and Pearce,1993)'
_computing_publication_material  SHELXL-93
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measurement_device       ' Enraf-Nonius CAD4'
_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     0.71073
_diffrn_reflns_av_R_equivalents  0.0206
_diffrn_reflns_av_sigmaI/netI    0.0370
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            2954
_diffrn_reflns_theta_max         24.98
_diffrn_reflns_theta_min         2.41
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  120
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    0.273
_exptl_crystal_density_diffrn    1.087
_exptl_crystal_F_000             1184
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.769
_refine_diff_density_min         -0.399
_refine_diff_density_rms         0.068
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.048
_refine_ls_goodness_of_fit_obs   1.090
_refine_ls_hydrogen_treatment    riding
_refine_ls_matrix_type           full
_refine_ls_number_parameters     91
_refine_ls_number_reflns         1513
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.048
_refine_ls_restrained_S_obs      1.090
_refine_ls_R_factor_all          0.0757
_refine_ls_R_factor_obs          0.0582
_refine_ls_shift/esd_max         -0.003
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0826P)^2^+8.2393P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1673
_refine_ls_wR_factor_obs         0.1528
_reflns_number_observed          1184
_reflns_number_total             1513
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            904043Isup1.cif
_cod_data_source_block           apr298
_cod_depositor_comments
;
The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0826P)^2^+8.2393P] 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^)+(0.0826P)^2^+8.2393P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      Cmca
_cod_database_code               7027564