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_2019873
_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          462
_chemical_name_common
;
5-Cyclohexyl-5-ethylbarbituric acid form II
;
_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           15
_space_group_name_Hall           '-C 2yc'
_space_group_name_H-M_alt        'C 1 2/c 1'
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/6
_cell_angle_alpha                90
_cell_angle_beta                 116.989(5)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   12.5071(7)
_cell_length_b                   21.0741(9)
_cell_length_c                   10.3310(5)
_cell_measurement_reflns_used    4171
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      67.3114
_cell_measurement_theta_min      3.9631
_cell_volume                     2426.5(2)
_computing_cell_refinement
;
CrysAlis PRO (Oxford Diffraction, 2010)
;
_computing_data_collection
;
CrysAlis PRO (Oxford Diffraction, 2010)
;
_computing_data_reduction
;
CrysAlis PRO (Oxford Diffraction, 2010)
;
_computing_molecular_graphics
;
XP (Bruker, 1998) and Mercury (Macrae <i>et al.</i>,  2008)
;
_computing_publication_material
;
publCIF (Westrip, 2010)
;
_computing_structure_refinement
;
SHELXL2014 (Sheldrick, 2015)
;
_computing_structure_solution
;
SHELXS97 (Sheldrick, 2008)
;
_diffrn_ambient_temperature      173(2)
_diffrn_detector_area_resol_mean 10.3575
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type
'Oxford Xcalibur diffractometer with Gemini Ultra Ruby CCD detector [OK?]'
_diffrn_measurement_method       \w
_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  0.0243
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            6607
_diffrn_reflns_theta_full        67.680
_diffrn_reflns_theta_max         67.422
_diffrn_reflns_theta_min         4.196
_exptl_absorpt_coefficient_mu    0.774
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.93175
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(CrysAlis PRO; Oxford Diffraction, 2010)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.305
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1024
_exptl_crystal_size_max          0.600
_exptl_crystal_size_mid          0.080
_exptl_crystal_size_min          0.080
_refine_diff_density_max         0.287
_refine_diff_density_min         -0.228
_refine_ls_extinction_coef       0.00111(15)
_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   1.080
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     164
_refine_ls_number_reflns         2188
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.080
_refine_ls_R_factor_all          0.0388
_refine_ls_R_factor_gt           0.0345
_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^)+(0.0583P)^2^+0.7034P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0961
_refine_ls_wR_factor_ref         0.0988
_reflns_number_gt                1897
_reflns_number_total             2188
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            cu3074sup1.cif
_cod_data_source_block           Ib
_cod_original_cell_volume        2426.4(2)
_cod_database_code               2019873
_cod_database_fobs_code          2019873
_shelx_estimated_absorpt_t_min   0.654
_shelx_estimated_absorpt_t_max   0.941
_shelx_hkl_checksum              81489
_shelx_res_checksum              50822
_shelxl_version_number           2014/6