A hetero-alkali-metal version of the utility amide LDA: lithium-potassium diisopropylamide.
Armstrong, David R.; Kennedy, Alan R.; Mulvey, Robert E.; Robertson, Stuart D.; Dalton transactions (Cambridge, England : 2003) 42 (2013) 3704–3711; doi:10.1039/c2dt32204h

data_7022277
_publ_section_title
;
 A hetero-alkali-metal version of the utility amide LDA: lithium-potassium
 diisopropylamide.
;
_journal_issue                   10
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              3704
_journal_page_last               3711
_journal_paper_doi               10.1039/c2dt32204h
_journal_volume                  42
_journal_year                    2013
_chemical_formula_moiety         'C24 H58 K Li2 N5'
_chemical_formula_sum            'C24 H58 K Li2 N5'
_chemical_formula_weight         469.73
_chemical_name_systematic
;
?
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 116.115(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   15.7304(8)
_cell_length_b                   13.4168(5)
_cell_length_c                   16.7662(10)
_cell_measurement_reflns_used    4657
_cell_measurement_temperature    123(2)
_cell_measurement_theta_max      28.7861
_cell_measurement_theta_min      3.3180
_cell_volume                     3177.3(3)
_computing_cell_refinement
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.34.40 (release 27-08-2010 CrysAlis171 .NET)
(compiled Aug 27 2010,11:50:40)
;
_computing_data_collection
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.34.40 (release 27-08-2010 CrysAlis171 .NET)
(compiled Aug 27 2010,11:50:40)
;
_computing_data_reduction
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.34.40 (release 27-08-2010 CrysAlis171 .NET)
(compiled Aug 27 2010,11:50:40)
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      123(2)
_diffrn_measured_fraction_theta_full 0.962
_diffrn_measured_fraction_theta_max 0.881
_diffrn_measurement_device_type  'Xcalibur, Eos'
_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  0.0205
_diffrn_reflns_av_sigmaI/netI    0.0299
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            9117
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         28.85
_diffrn_reflns_theta_min         3.32
_exptl_absorpt_coefficient_mu    0.184
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.79945
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.34.40 (release 27-08-2010 CrysAlis171 .NET)
(compiled Aug 27 2010,11:50:40)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    0.982
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1048
_exptl_crystal_size_max          0.14
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.465
_refine_diff_density_min         -0.262
_refine_diff_density_rms         0.041
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.049
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     195
_refine_ls_number_reflns         3674
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.049
_refine_ls_R_factor_all          0.0570
_refine_ls_R_factor_gt           0.0454
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0543P)^2^+2.3317P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1147
_refine_ls_wR_factor_ref         0.1231
_reflns_number_gt                3071
_reflns_number_total             3674
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2dt32204h.txt
_cod_data_source_block           sdr1206
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               7022277