An alkoxide cluster with 18 Li^+^ ions encapsulating two borate anions, [(^<i>t^</i>BuO)~12~Li~18~(BO~3~)~2~]
Tombul, Mustafa; Errington, R. John; Coxall, Robert A.; Clegg, William; Acta Crystallographica Section C 59 (2003) m231–m233; doi:10.1107/S0108270103009636

data_2013296
_publ_section_title
;
 An alkoxide cluster with 18 Li^+^ ions encapsulating two borate
 anions, [(^<i>t^</i>BuO)~12~Li~18~(BO~3~)~2~]
;
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              m231
_journal_page_last               m233
_journal_paper_doi               10.1107/S0108270103009636
_journal_volume                  59
_journal_year                    2003
_chemical_formula_iupac          '[Li18 (B1 O3)2 (C4 H9 O1)12]'
_chemical_formula_moiety         'C48 H108 B2 Li18 O18'
_chemical_formula_sum            'C48 H108 B2 Li18 O18'
_chemical_formula_weight         1119.88
_chemical_name_systematic
;
Bis(borato)dodeca(tert-butoxo)octadecalithium
;
_space_group_IT_number           148
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  '-R 3'
_symmetry_space_group_name_H-M   'R -3 :H'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            3
_cell_length_a                   19.917(3)
_cell_length_b                   19.917(3)
_cell_length_c                   15.608(3)
_cell_measurement_reflns_used    1806
_cell_measurement_temperature    200(2)
_cell_measurement_theta_max      25.6
_cell_measurement_theta_min      2.7
_cell_volume                     5362.0(15)
_computing_cell_refinement       'local programs'
_computing_data_collection       'SMART (Bruker, 2001)'
_computing_data_reduction        'SAINT (Bruker, 2001)'
_computing_molecular_graphics    SHELXTL
_computing_publication_material  'SHELXTL and local programs'
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Sheldrick, 2001)'
_diffrn_ambient_temperature      200(2)
_diffrn_detector_area_resol_mean 8.192
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.892
_diffrn_measurement_device_type  'Bruker SMART 1K CCD diffractometer'
_diffrn_measurement_method       'narrow-frame \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0700
_diffrn_reflns_av_sigmaI/netI    0.0780
_diffrn_reflns_limit_h_max       26
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            6484
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         28.46
_diffrn_reflns_theta_min         1.76
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.070
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.040
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1812
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.173
_refine_diff_density_min         -0.177
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.132
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     136
_refine_ls_number_reflns         2682
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.132
_refine_ls_R_factor_all          0.1519
_refine_ls_R_factor_gt           0.0782
_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^)+(0.0283P)^2^+9.227P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1256
_refine_ls_wR_factor_ref         0.1526
_reflns_number_gt                1502
_reflns_number_total             2682
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            gg1167.cif
_cod_data_source_block           I
_cod_original_cell_volume        5362.0(16)
_cod_original_sg_symbol_H-M      'R -3'
_cod_database_code               2013296
_cod_database_fobs_code          2013296