Ligand Binding Constants to Lithium Hexamethyldisilazide (LiHMDS) Determined by Diffusion-ordered NMR Spectroscopy (DOSY).
Tai, Onkei; Hopson, Russell; Williard, Paul G.; The Journal of organic chemistry  (2017) –; doi:10.1021/acs.joc.7b00800

data_4032574
_publ_section_title
;
 Ligand Binding Constants to Lithium Hexamethyldisilazide (LiHMDS)
 Determined by Diffusion-ordered NMR Spectroscopy (DOSY).
;
_journal_name_full               'The Journal of organic chemistry'
_journal_paper_doi               10.1021/acs.joc.7b00800
_journal_year                    2017
_chemical_formula_moiety         'C22 H56 Li2 N2 O2 Si4'
_chemical_formula_sum            'C22 H56 Li2 N2 O2 Si4'
_chemical_formula_weight         506.92
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_primary     direct
_audit_creation_date             2016-07-08
_audit_creation_method
;
Olex2 1.2
(compiled 2016.02.16 svn.r3265 for OlexSys, GUI svn.r5155)
;
_cell_angle_alpha                90
_cell_angle_beta                 99.343(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.2754(5)
_cell_length_b                   20.029(1)
_cell_length_c                   17.8817(9)
_cell_measurement_reflns_used    7649
_cell_measurement_temperature    173.2
_cell_measurement_theta_max      24.41
_cell_measurement_theta_min      2.45
_cell_volume                     3277.9(3)
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'olex2.refine (Bourhis et al., 2015)'
_computing_structure_solution    'ShelXS (Sheldrick, 2008)'
_diffrn_ambient_temperature      173.2
_diffrn_measured_fraction_theta_full 0.9893
_diffrn_measured_fraction_theta_max 0.9893
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0454
_diffrn_reflns_av_unetI/netI     0.0490
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            22793
_diffrn_reflns_theta_full        26.0000
_diffrn_reflns_theta_max         24.59
_diffrn_reflns_theta_min         2.23
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.200
_exptl_absorpt_correction_T_max  0.7451
_exptl_absorpt_correction_T_min  0.7121
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details
;
SADABS-2014/5 (Bruker,2014) was used for absorption correction.
wR2(int) was 0.1136 before and 0.0479 after correction.
The Ratio of minimum to maximum transmission is 0.9557.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.0271
_exptl_crystal_description       brick
_exptl_crystal_F_000             1121.5899
_exptl_crystal_size_max          0.2
_exptl_crystal_size_mid          0.19
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.5143
_refine_diff_density_min         -0.3680
_refine_diff_density_rms         0.0925
_refine_ls_d_res_high            0.8540
_refine_ls_d_res_low             9.1524
_refine_ls_goodness_of_fit_ref   1.0602
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_constraints    78
_refine_ls_number_parameters     300
_refine_ls_number_reflns         5445
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.0602
_refine_ls_R_factor_all          0.0794
_refine_ls_R_factor_gt           0.0473
_refine_ls_shift/su_max          0.0001
_refine_ls_shift/su_mean         0.0000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0426P)^2^+1.8018P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0963
_refine_ls_wR_factor_ref         0.1091
_reflns_Friedel_coverage         0.0
_reflns_limit_h_max              10
_reflns_limit_h_min              -10
_reflns_limit_k_max              23
_reflns_limit_k_min              0
_reflns_limit_l_max              20
_reflns_limit_l_min              0
_reflns_number_gt                3956
_reflns_number_total             5445
_reflns_threshold_expression     I>=2u(I)
_cod_data_source_file            jo7b00800_si_004.cif
_cod_data_source_block           ot08jul16_0m_a
_cod_depositor_comments
;

2020-10-02
Z value and formula fixed to values more according to usual
chemical conventions.                 miguel
;
_cod_original_formula_moiety     '0.5(C22 H56 Li2 N2 O2 Si4)'
_cod_original_formula_sum        'C11 H28 Li N O Si2'
_cod_original_formula_units_Z    8
_cod_original_formula_weight     253.46
_cod_database_code               4032574
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2.a Secondary CH2 refined with riding coordinates:
 C13(H13a,H13b), C14(H14a,H14b), C15(H15a,H15b), C16(H16a,H16b), C17(H17a,
 H17b), C18(H18a,H18b), C19(H19a,H19b), C20(H20a,H20b), C21(H21a,H21b),
 C22(H22a,H22b)
2.b Idealised Me refined as rotating group:
 C1(H1a,H1b,H1c), C2(H2a,H2b,H2c), C3(H3a,H3b,H3c), C4(H4a,H4b,H4c), C5(H5a,
 H5b,H5c), C6(H6a,H6b,H6c), C7(H7a,H7b,H7c), C8(H8a,H8b,H8c), C9(H9a,H9b,H9c),
 C10(H10a,H10b,H10c), C11(H11a,H11b,H11c), C12(H12a,H12b,H12c)
;
_olex2_submission_special_instructions 'No special instructions were received'