The importance of screening solid-state phases of a racemic modification of a chiral drug: thermodynamic and structural characterization of solid-state phases of etiracetam
Herman, Christelle; Vermylen, Valérie; Norberg, Bernadette; Wouters, Johan; Leyssens, Tom; Acta Crystallographica Section B 69 (2013) 371–378; doi:10.1107/S2052519213015054

data_2105493
_publ_section_title
;
 The importance of screening solid-state phases of a racemic modification
 of a chiral drug: thermodynamic and structural characterization of
 solid-state phases of etiracetam
;
_journal_coeditor_code           ZB5029
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              371
_journal_page_last               378
_journal_paper_doi               10.1107/S2052519213015054
_journal_volume                  69
_journal_year                    2013
_chemical_formula_sum            'C8 H14 N2 O2'
_chemical_formula_weight         170.21
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/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                 95.966(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.3020(8)
_cell_length_b                   11.5223(7)
_cell_length_c                   8.4172(5)
_cell_measurement_temperature    293(2)
_cell_volume                     897.27(11)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 10.3712
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.913
_diffrn_measurement_device_type  'Xcalibur, Ruby, Gemini ultra'
_diffrn_measurement_method       '\w 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  0.0640
_diffrn_reflns_av_sigmaI/netI    0.2418
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            5986
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         32.55
_diffrn_reflns_theta_min         3.54
_exptl_absorpt_coefficient_mu    0.091
_exptl_absorpt_correction_T_max  0.9964
_exptl_absorpt_correction_T_min  0.9820
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET)
(compiled Jan  5 2010,16:28:46)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_density_diffrn    1.260
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             368
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.193
_refine_diff_density_min         -0.167
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.659
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     110
_refine_ls_number_reflns         2982
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.659
_refine_ls_R_factor_all          0.2165
_refine_ls_R_factor_gt           0.0522
_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^)+(0.0709P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1080
_refine_ls_wR_factor_ref         0.1461
_reflns_number_gt                878
_reflns_number_total             2982
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            zb5029.cif
_cod_data_source_block           Etiracetam_FII
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2105493