5-Butyl-5-ethylbarbituric acid: a phase transition at low temperature
Nichol, Gary S.; Clegg, William; Acta Crystallographica Section C 61 (2005) o297–o299; doi:10.1107/S0108270105008486

data_2014902
_publ_section_title
;
 5-Butyl-5-ethylbarbituric acid: a phase transition at low temperature
;
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o297
_journal_page_last               o299
_journal_paper_doi               10.1107/S0108270105008486
_journal_volume                  61
_journal_year                    2005
_chemical_formula_iupac          'C10 H16 N2 O3'
_chemical_formula_moiety         'C10 H16 N2 O3'
_chemical_formula_sum            'C10 H16 N2 O3'
_chemical_formula_weight         212.25
_chemical_name_common            butobarbitone
_chemical_name_systematic
;
5-butyl-5-ethylbarbituric acid
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 96.7280(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   10.2220(9)
_cell_length_b                   11.0636(10)
_cell_length_c                   20.9787(18)
_cell_measurement_reflns_used    7041
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      30.42
_cell_measurement_theta_min      2.25
_cell_volume                     2356.2(4)
_computing_cell_refinement       'SAINT (Bruker, 2001)'
_computing_data_collection       'APEX2 (Bruker, 2003)'
_computing_data_reduction        SAINT
_computing_molecular_graphics
;DIAMOND (Brandenburg & Putz, 2004) and Mercury 1.3 (Bruno <i>et al.</i>,
 2002)
;
_computing_publication_material  'SHELXTL and local programs'
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Sheldrick, 2001)'
_diffrn_ambient_temperature      120(2)
_diffrn_measured_fraction_theta_full 0.977
_diffrn_measured_fraction_theta_max 0.977
_diffrn_measurement_device_type  'Bruker APEX2 CCD diffractometer'
_diffrn_measurement_method       'Thin-slice \w scans'
_diffrn_radiation_monochromator  'silicon 111'
_diffrn_radiation_source         'Daresbury SRS station 9.8'
_diffrn_radiation_type           synchrotron
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_diffrn_reflns_av_R_equivalents  0.0327
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_diffrn_reflns_limit_h_max       12
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_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            17357
_diffrn_reflns_theta_full        24.34
_diffrn_reflns_theta_max         24.34
_diffrn_reflns_theta_min         2.07
_diffrn_standards_decay_%        10
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.089
_exptl_absorpt_correction_T_max  0.997
_exptl_absorpt_correction_T_min  0.842
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 2003)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.197
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             912
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.544
_refine_diff_density_min         -0.296
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.048
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     288
_refine_ls_number_reflns         4049
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.048
_refine_ls_R_factor_all          0.0703
_refine_ls_R_factor_gt           0.0616
_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^)+(0.097P)^2^+1.2316P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1661
_refine_ls_wR_factor_ref         0.1752
_reflns_number_gt                3432
_reflns_number_total             4049
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sk1827.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2014902
_cod_database_fobs_code          2014902