Model for a superbase: synthesis and crystal structure of the mixed-metal/mixed-anion aggregate [NaLi2{N(H)R}2(OR′)]2†
Holland, Rebecca; Jeffery, John C.; Russell, Christopher A.; Journal of the Chemical Society, Dalton Transactions  (1999) 3331–; doi:10.1039/a906649g

data_7027774
_publ_section_title
;
 Model for a superbase: synthesis and crystal structure of the
 mixed-metal/mixed-anion aggregate [NaLi2{N(H)R}2(OR&#x2032;)]2&#x2020;
;
_journal_issue                   19
_journal_name_full
'Journal of the Chemical Society, Dalton Transactions'
_journal_page_first              3331
_journal_paper_doi               10.1039/a906649g
_journal_year                    1999
_chemical_formula_sum            'C52 H82 Li4 N4 Na2 O10'
_chemical_formula_weight         996.96
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_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                 93.05(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   9.169(4)
_cell_length_b                   13.666(5)
_cell_length_c                   22.173(10)
_cell_measurement_temperature    173(2)
_cell_volume                     2774(2)
_computing_cell_refinement       SMART
_computing_data_collection       SMART
_computing_data_reduction        SAINT
_computing_molecular_graphics    XP
_computing_publication_material  XCIF
_computing_structure_refinement  'SHELXL-93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measurement_device       'Siemens SMART Area Detector'
_diffrn_measurement_method
'\w rotation with narrow frames (0.3 degrees)'
_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  0.0839
_diffrn_reflns_av_sigmaI/netI    0.0854
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       28
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            11443
_diffrn_reflns_theta_max         22.50
_diffrn_reflns_theta_min         1.75
_exptl_absorpt_coefficient_mu    0.093
_exptl_absorpt_correction_T_max  0.98
_exptl_absorpt_correction_T_min  0.98
_exptl_absorpt_correction_type   'Empirical, pseudo-azimuthal scan (SADABS)'
_exptl_crystal_density_diffrn    1.193
_exptl_crystal_F_000             1072
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.833
_refine_diff_density_min         -0.388
_refine_diff_density_rms         0.117
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.236
_refine_ls_goodness_of_fit_obs   1.442
_refine_ls_matrix_type           full
_refine_ls_number_parameters     325
_refine_ls_number_reflns         3624
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.236
_refine_ls_restrained_S_obs      1.442
_refine_ls_R_factor_all          0.1684
_refine_ls_R_factor_obs          0.1347
_refine_ls_shift/esd_max         -0.003
_refine_ls_shift/esd_mean        0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0972P)^2^+28.2094P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.3471
_refine_ls_wR_factor_obs         0.3322
_reflns_number_observed          2505
_reflns_number_total             3624
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            906649gsup1.cif
_cod_data_source_block           nap
_cod_depositor_comments
;
The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0972P)^2^+28.2094P] 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^)+(0.0972P)^2^+28.2094P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        2774.2(20)
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               7027774