A Remarkable Isostructural Homologous Series of Mixed Lithium-Heavier Alkali Metaltert-Butoxides [(t-BuO)8Li4M4] (M = Na, K, Rb or Cs)
David R. Armstrong; William Clegg; Allison M. Drummond; Stephen T. Liddle; Robert E. Mulvey; Journal of the American Chemical Society 122 (2000) 11117–11124; doi:10.1021/ja002217z

data_4116233
_publ_section_title
;
 A Remarkable Isostructural Homologous Series of Mixed Lithium-Heavier
 Alkali Metaltert-Butoxides [(t-BuO)8Li4M4] (M = Na, K, Rb or Cs)
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              11117
_journal_page_last               11124
_journal_paper_doi               10.1021/ja002217z
_journal_volume                  122
_journal_year                    2000
_chemical_formula_sum            'C32 H72 Li4 O8 Rb4'
_chemical_formula_weight         954.54
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           11
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yb'
_symmetry_space_group_name_H-M   'P 1 21/m 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.000(2)
_cell_angle_beta                 110.347(19)
_cell_angle_gamma                90.000(2)
_cell_formula_units_Z            2
_cell_length_a                   11.705(3)
_cell_length_b                   17.070(5)
_cell_length_c                   12.957(5)
_cell_measurement_reflns_used    4907
_cell_measurement_temperature    160(2)
_cell_measurement_theta_max      27.92
_cell_measurement_theta_min      2.39
_cell_volume                     2427.3(14)
_computing_cell_refinement       'local programs'
_computing_data_collection       'Siemens SMART'
_computing_data_reduction        'Siemens SAINT'
_computing_molecular_graphics    'Siemens SHELXTL'
_computing_publication_material  'SHELXTL and local programs'
_computing_structure_refinement  'Siemens SHELXTL'
_computing_structure_solution    'Siemens SHELXTL'
_diffrn_ambient_temperature      160(2)
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.903
_diffrn_measurement_device_type  'Siemens SMART CCD diffractometer'
_diffrn_measurement_method       '\w rotation with narrow frames'
_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  0.0471
_diffrn_reflns_av_sigmaI/netI    0.0865
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            11978
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         28.38
_diffrn_reflns_theta_min         1.86
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    4.044
_exptl_absorpt_correction_T_max  0.1358
_exptl_absorpt_correction_T_min  0.0500
_exptl_absorpt_correction_type   empirical
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.306
_exptl_crystal_description       block
_exptl_crystal_F_000             976
_exptl_crystal_size_max          0.80
_exptl_crystal_size_mid          0.80
_exptl_crystal_size_min          0.80
_refine_diff_density_max         0.763
_refine_diff_density_min         -0.803
_refine_diff_density_rms         0.093
_refine_ls_extinction_coef       0.0011(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.904
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     240
_refine_ls_number_reflns         5679
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.904
_refine_ls_R_factor_all          0.0991
_refine_ls_R_factor_gt           0.0437
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0517P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0976
_refine_ls_wR_factor_ref         0.1088
_reflns_number_gt                3022
_reflns_number_total             5679
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja002217z_3.cif
_cod_data_source_block           rem250
_cod_original_cell_volume        2427.4(14)
_cod_database_code               4116233