Two polymorphs of 5-cyclohexyl-5-ethylbarbituric acid and their packing relationships with other barbiturates
Gelbrich, Thomas; Meischberger, Isabella; Griesser, Ulrich J.; Acta Crystallographica Section C 71 (2015) –; doi:10.1107/S2053229615002880

data_2019872
_publ_section_title
;
 Two polymorphs of 5-cyclohexyl-5-ethylbarbituric acid and their packing
 relationships with other barbiturates
;
_journal_coeditor_code           CU3074
_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first
;
;
_journal_paper_doi               10.1107/S2053229615002880
_journal_volume                  71
_journal_year                    2015
_chemical_formula_iupac          'C12 H18 N2 O3'
_chemical_formula_moiety         'C12 H18 N2 O3'
_chemical_formula_sum            'C12 H18 N2 O3'
_chemical_formula_weight         238.28
_chemical_melting_point          473
_chemical_name_common
;
5-Cyclohexyl-5-ethylbarbituric acid form I
;
_chemical_name_systematic
;
5-Cyclohexyl-5-ethylpyrimidine-2,4,6(1<i>H</i>,3<i>H</i>,5<i>H</i>)-trione
;
_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'
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   mixed
_audit_creation_method           SHELXL-2014/6
_cell_angle_alpha                90
_cell_angle_beta                 95.896(2)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   17.9322(4)
_cell_length_b                   10.4961(3)
_cell_length_c                   13.2006(4)
_cell_measurement_reflns_used    12888
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      25.35
_cell_measurement_theta_min      2.91
_cell_volume                     2471.45(12)
_computing_cell_refinement
;
DENZO (Otwinowski & Minor, 1997) and COLLECT (Nonius, 1998)
;
_computing_data_collection
;
COLLECT (Nonius, 1998)
;
_computing_data_reduction
;
DENZO (Otwinowski & Minor, 1997) and COLLECT (Nonius, 1998)
;
_computing_molecular_graphics
;
XP (Bruker, 1998) and Mercury (Macrae <i>et al.</i>,  2008)
;
_computing_publication_material
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publCIF (Westrip, 2010)
;
_computing_structure_refinement
;
SHELXL2014 (Sheldrick, 2015)
;
_computing_structure_solution
;
SHELXS97 (Sheldrick, 2008)
;
_diffrn_ambient_temperature      120(2)
_diffrn_detector_area_resol_mean 65.3
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.991
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'Bruker Nonius APEXII CCD camera on \k-goniostat'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0536
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -21
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            18686
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.396
_diffrn_reflns_theta_min         2.997
_exptl_absorpt_coefficient_mu    0.093
_exptl_absorpt_correction_T_max  0.9982
_exptl_absorpt_correction_T_min  0.9890
_exptl_absorpt_correction_type   multi-scan
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;
(SADABS2007; Sheldrick, 2007)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.281
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1024
_exptl_crystal_size_max          0.120
_exptl_crystal_size_mid          0.120
_exptl_crystal_size_min          0.020
_refine_diff_density_max         0.283
_refine_diff_density_min         -0.220
_refine_ls_extinction_coef       0.0025(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method
;
SHELXL2014 (Sheldrick, 2015)
;
_refine_ls_goodness_of_fit_ref   1.081
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     326
_refine_ls_number_reflns         4513
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      1.080
_refine_ls_R_factor_all          0.0874
_refine_ls_R_factor_gt           0.0611
_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^)+3.5813P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1108
_refine_ls_wR_factor_ref         0.1246
_reflns_number_gt                3416
_reflns_number_total             4513
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            cu3074sup1.cif
_cod_data_source_block           Ia
_cod_database_code               2019872
_cod_database_fobs_code          2019872
_shelx_estimated_absorpt_t_min   0.989
_shelx_estimated_absorpt_t_max   0.998
_shelx_hkl_checksum              27302
_shelx_res_checksum              87456
_shelxl_version_number           2014/6