Bis(1,3-dimethyl-1<i>H</i>-imidazolium) hexafluorosilicate: the second monoclinic polymorph
Tian, Chong; Nie, Wanli; Borzov, Maxim V.; Acta Crystallographica Section E 69 (2013) o1218–o1219; doi:10.1107/S1600536813018242

data_2238388
_publ_section_title
;
 Bis(1,3-dimethyl-1<i>H</i>-imidazolium) hexafluorosilicate: the second
 monoclinic polymorph
;
_journal_issue                   8
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1218
_journal_page_last               o1219
_journal_paper_doi               10.1107/S1600536813018242
_journal_volume                  69
_journal_year                    2013
_chemical_formula_iupac          '2C5 H9 N2+ , Si F6 2-'
_chemical_formula_moiety         'F6 Si, 2(C5 H9 N2)'
_chemical_formula_sum            'C10 H18 F6 N4 Si'
_chemical_formula_weight         336.38
_chemical_melting_point          550
_chemical_name_systematic
;
Bis(1,3-dimethyl-1<i>H</i>-imidazolium) hexafluorosilicate
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.1060(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   8.2240(8)
_cell_length_b                   9.7901(9)
_cell_length_c                   8.7753(9)
_cell_measurement_reflns_used    3479
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      28.32
_cell_measurement_theta_min      2.32
_cell_volume                     706.53(12)
_computing_cell_refinement       'SAINT (Bruker, 2007)'
_computing_data_collection       'APEX2 (Bruker, 2007)'
_computing_data_reduction        'SAINT (Bruker, 2007)'
_computing_molecular_graphics
;
SHELXTL (Sheldrick, 2008) and OLEX2 (Dolomanov <i>et al.</i>,
2009)
;
_computing_publication_material
;
SHELXTL (Sheldrick, 2008) and OLEX2 (Dolomanov <i>et al.</i>,
2009)
;
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_detector_area_resol_mean 8.333
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Bruker SMART APEXII'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0195
_diffrn_reflns_av_sigmaI/netI    0.0224
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            3670
_diffrn_reflns_theta_full        25.99
_diffrn_reflns_theta_max         25.99
_diffrn_reflns_theta_min         3.24
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.233
_exptl_absorpt_correction_T_max  0.9884
_exptl_absorpt_correction_T_min  0.9125
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 1996)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.581
_exptl_crystal_density_method    none
_exptl_crystal_description       plate
_exptl_crystal_F_000             348
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.39
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.182
_refine_diff_density_min         -0.220
_refine_ls_extinction_coef       0.065(7)
_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   1.094
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     134
_refine_ls_number_reflns         1373
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.094
_refine_ls_R_factor_all          0.0309
_refine_ls_R_factor_gt           0.0275
_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^)+(0.0471P)^2^+0.1056P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0788
_refine_ls_wR_factor_ref         0.0811
_reflns_number_gt                1228
_reflns_number_total             1373
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ld2107.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2238388
_cod_database_fobs_code          2238388