Supramolecular constructs and thermodynamic stability of four polymorphs and a co-crystal of pentobarbital (nembutal)
Rossi, Denise; Gelbrich, Thomas; Kahlenberg, Volker; Griesser, Ulrich J.; CrystEngComm 14 (2012) 2494–; doi:10.1039/c2ce06659a

data_7207655
_publ_section_title
;
 Supramolecular constructs and thermodynamic stability of four polymorphs
 and a co-crystal of pentobarbital (nembutal)
;
_journal_issue                   7
_journal_name_full               CrystEngComm
_journal_page_first              2494
_journal_paper_doi               10.1039/c2ce06659a
_journal_volume                  14
_journal_year                    2012
_chemical_formula_sum            'C11 H18 N2 O3'
_chemical_formula_weight         226.27
_chemical_name_common            'pentobarbital, nembutal'
_chemical_name_systematic
;

5-ethyl,5-(1-methylbutyl)barbituric acid
;
_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                 104.762(6)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   14.5136(10)
_cell_length_b                   6.8344(3)
_cell_length_c                   12.4979(6)
_cell_measurement_reflns_used    1627
_cell_measurement_temperature    123(2)
_cell_measurement_theta_max      62.7308
_cell_measurement_theta_min      3.6607
_cell_volume                     1198.77(12)
_computing_cell_refinement
;
CrysAlisPro, Oxford Diffraction Ltd.
;
_computing_data_collection
;
CrysAlisPro, Oxford Diffraction Ltd.
;
_computing_data_reduction
;
CrysAlisPro, Oxford Diffraction Ltd.
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      123(2)
_diffrn_measured_fraction_theta_full 0.955
_diffrn_measured_fraction_theta_max 0.955
_diffrn_measurement_device_type  'Xcalibur, Ruby, Gemini ultra'
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_source         'Enhance Ultra (Cu) X-ray Source'
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.5418
_diffrn_reflns_av_R_equivalents  0.0538
_diffrn_reflns_av_sigmaI/netI    0.0677
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            4960
_diffrn_reflns_theta_full        62.69
_diffrn_reflns_theta_max         62.69
_diffrn_reflns_theta_min         7.21
_exptl_absorpt_coefficient_mu    0.754
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.85416
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Oxford Diffraction Ltd.,
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.254
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             488
_exptl_crystal_size_max          0.36
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.01
_refine_diff_density_max         0.245
_refine_diff_density_min         -0.221
_refine_diff_density_rms         0.048
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.106
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     183
_refine_ls_number_reflns         1839
_refine_ls_number_restraints     20
_refine_ls_restrained_S_all      1.146
_refine_ls_R_factor_all          0.1035
_refine_ls_R_factor_gt           0.0640
_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^)+(0.0300P)^2^+0.7000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1260
_refine_ls_wR_factor_ref         0.1332
_reflns_number_gt                1051
_reflns_number_total             1839
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2ce06659a.txt
_cod_data_source_block           Nbtl-IV
_cod_original_cell_volume        1198.77(11)
_cod_original_sg_symbol_H-M      P21/c
_cod_database_code               7207655