Crystal polymorphism in 1-butyl-3-methlimidazolium halides: supporting ionic liquid formation by inhibition of crystallisation
John D. Holbrey; W. Matthew Reichert; Mark Nieuwenhuyzen; Suzanne Johnson; Kenneth R. Seddon; Robin D. Rogers; Chemical communications (Cambridge, England)  (2003) 1636–1637; doi:10.1039/b304543a

data_7103777
_publ_section_title
;
Crystal polymorphism in 1-butyl-3-methlimidazolium
halides: supporting ionic liquid formation by inhibition of
crystallisation
;
_journal_issue                   14
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              1636
_journal_page_last               1637
_journal_paper_doi               10.1039/b304543a
_journal_year                    2003
_chemical_formula_sum            'C8 H15 Br N2'
_chemical_formula_weight         219.13
_chemical_name_common            '1-butyl-3-methylimidazolium bromide'
_chemical_name_systematic        '1-butyl-3-methylimidazolium bromide'
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      33
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.0649(4)
_cell_length_b                   11.8628(5)
_cell_length_c                   8.4306(3)
_cell_measurement_reflns_used    964
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      0.97
_cell_measurement_theta_min      0.52
_cell_volume                     1006.60(7)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.988
_diffrn_measured_fraction_theta_max 0.988
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1051
_diffrn_reflns_av_sigmaI/netI    0.0758
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            6023
_diffrn_reflns_theta_full        27.87
_diffrn_reflns_theta_max         27.87
_diffrn_reflns_theta_min         2.65
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    4.030
_exptl_absorpt_correction_T_max  0.97
_exptl_absorpt_correction_T_min  0.78
_exptl_absorpt_correction_type   sphere
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.446
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Fragment
_exptl_crystal_F_000             448
_exptl_crystal_size_max          1.1
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.2
_refine_diff_density_max         1.222
_refine_diff_density_min         -1.023
_refine_diff_density_rms         0.141
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.00
_refine_ls_extinction_coef       0.005(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   1.056
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     161
_refine_ls_number_reflns         2298
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.056
_refine_ls_R_factor_all          0.0674
_refine_ls_R_factor_gt           0.0552
_refine_ls_shift/su_max          0.006
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0639P)^2^+2.0282P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1216
_refine_ls_wR_factor_ref         0.1286
_reflns_number_gt                2018
_reflns_number_total             2298
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b304543a.txt
_cod_data_source_block           bmimbr
_cod_original_sg_symbol_H-M      Pna21
_cod_database_code               7103777