Hiding in Plain Sight: Polymorphs of Riluzole
Rahman Al Ahmad, Abdel; Maris, Thierry; Wuest, James D.; Crystal Growth & Design 25 (2025) 3029–3036; doi:10.1021/acs.cgd.5c00089

data_4519494
_publ_section_title
;
 Hiding in Plain Sight: Polymorphs of Riluzole
;
_journal_name_full               'Crystal Growth & Design'
_journal_page_first              3029
_journal_page_last               3036
_journal_paper_doi               10.1021/acs.cgd.5c00089
_journal_volume                  25
_journal_year                    2025
_chemical_formula_moiety         'C8 H5 F3 N2 O S'
_chemical_formula_sum            'C8 H5 F3 N2 O S'
_chemical_formula_weight         234.20
_chemical_name_common            Riluzole
_chemical_name_systematic        6-(trifluoromethoxy)-1,3-benzothiazol-2-amine
_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'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     dual
_audit_creation_date             2022-06-13
_audit_creation_method
;
FinalCif V106 by Daniel Kratzert, Freiburg 2022,
https://dkratzert.de/finalcif.html
;
_cell_angle_alpha                90
_cell_angle_beta                 101.502(3)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   19.2771(10)
_cell_length_b                   8.1248(4)
_cell_length_c                   11.7665(6)
_cell_measurement_reflns_used    6867
_cell_measurement_temperature    150
_cell_measurement_theta_max      54.325
_cell_measurement_theta_min      4.074
_cell_volume                     1805.89(16)
_computing_cell_refinement
;
SAINT (2019) V8.40A; Integration Software for Single Crystal Data.
Bruker AXS Inc., Madison, WI 53719-1173.
;
_computing_data_collection
;
APEX 3 (2019) Bruker AXS Inc., Madison, WI 53719-1173.
;
_computing_data_reduction
;
SAINT (2019) V8.40A; Integration Software for Single Crystal Data.
Bruker AXS Inc., Madison, WI 53719-1173.
;
_computing_molecular_graphics    'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_structure_refinement  'XL  (Sheldrick, 2008)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      150
_diffrn_detector                 'CMOS Area detector'
_diffrn_detector_area_resol_mean 10.42
_diffrn_detector_type            'Bruker CMOS Photon III '
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_device       'k-geometry diffractometer'
_diffrn_measurement_device_type  'Bruker Venture Metaljet'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_radiation_collimation    'Focusing mirrors'
_diffrn_radiation_monochromator  'Helios MX Mirror Optics'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Ga K\a'
_diffrn_radiation_wavelength     1.34139
_diffrn_reflns_av_R_equivalents  0.0551
_diffrn_reflns_av_unetI/netI     0.0541
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.990
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            15269
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.990
_diffrn_reflns_theta_full        53.594
_diffrn_reflns_theta_max         55.086
_diffrn_reflns_theta_min         4.072
_diffrn_source                   'Metal Jet'
_diffrn_source_current           2.86
_diffrn_source_power             0.1993706
_diffrn_source_target            Ga
_diffrn_source_type              'Gallium Liquid Metal Jet Source'
_diffrn_source_voltage           69.71
_exptl_absorpt_coefficient_mu    2.268
_exptl_absorpt_correction_T_max  0.3027
_exptl_absorpt_correction_T_min  0.1832
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2016/2 (Bruker,2016/2) was used for absorption correction.
wR2(int) was 0.1051 before and 0.0708 after correction.
The Ratio of minimum to maximum transmission is 0.6052.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            'clear light colourless'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   light
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.723
_exptl_crystal_description       plate
_exptl_crystal_F_000             944
_exptl_crystal_recrystallization_method 'crystalised from EtOAc'
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.09
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.387
_refine_diff_density_min         -0.377
_refine_diff_density_rms         0.087
_refine_ls_extinction_coef       0.0030(5)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2018/3 (Sheldrick 2018)'
_refine_ls_goodness_of_fit_ref   1.049
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     284
_refine_ls_number_reflns         3418
_refine_ls_number_restraints     6
_refine_ls_restrained_S_all      1.048
_refine_ls_R_factor_all          0.0813
_refine_ls_R_factor_gt           0.0547
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0887P)^2^+0.9315P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1414
_refine_ls_wR_factor_ref         0.1586
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                2459
_reflns_number_total             3418
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            RZ_P21c_101_150K_jw2457_4_.cif
_cod_data_source_block           jw24574
_cod_database_code               4519494
_cod_database_fobs_code 4519494