Stabilisation of sodium complexes of 18-crown-6 by intramolecular hydrogen bonding †
Steed, Jonathan W.; Junk, Peter C.; Journal of the Chemical Society, Dalton Transactions  (1999) 2141–; doi:10.1039/a902358e

data_7027421
_publ_section_title
;
 Stabilisation of sodium complexes of 18-crown-6 by intramolecular
 hydrogen bonding&#x200A;&#x2020;
;
_journal_issue                   13
_journal_name_full
'Journal of the Chemical Society, Dalton Transactions'
_journal_page_first              2141
_journal_paper_doi               10.1039/a902358e
_journal_year                    1999
_chemical_formula_sum            'C12 H28 I3 Na O8'
_chemical_formula_weight         704.03
_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                 109.989(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   20.6803(8)
_cell_length_b                   11.0480(5)
_cell_length_c                   10.8675(3)
_cell_measurement_temperature    123(2)
_cell_volume                     2333.38(16)
_computing_cell_refinement       Denzo-smn
_computing_data_reduction        Denzo-smn
_computing_molecular_graphics    RES2INS
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      123(2)
_diffrn_measured_fraction_theta_full 0.972
_diffrn_measured_fraction_theta_max 0.972
_diffrn_measurement_device_type  KappaCCD
_diffrn_measurement_method       '2o phi frames'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71070
_diffrn_reflns_av_R_equivalents  0.031
_diffrn_reflns_av_sigmaI/netI    0.0426
_diffrn_reflns_limit_h_max       25
_diffrn_reflns_limit_h_min       -25
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            10176
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         3.60
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    4.066
_exptl_absorpt_correction_T_max  0.8225
_exptl_absorpt_correction_T_min  0.4968
_exptl_absorpt_correction_type   Scalepack
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    2.004
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             1336
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.951
_refine_diff_density_min         -1.097
_refine_diff_density_rms         0.104
_refine_ls_extinction_coef       0.00086(11)
_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   1.082
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     121
_refine_ls_number_reflns         2241
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.082
_refine_ls_R_factor_all          0.0266
_refine_ls_R_factor_gt           0.0246
_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^)+(0.0219P)^2^+3.3232P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0615
_refine_ls_wR_factor_ref         0.0628
_reflns_number_gt                2088
_reflns_number_total             2241
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            902358esup1.cif
_cod_data_source_block           nai18
_cod_original_cell_volume        2333.38(15)
_cod_original_sg_symbol_H-M      C2/c
_cod_database_code               7027421