Piperazine-2,3,5,6-tetraone
Jia, Jing-Jing; Meng, Xiu-Jin; Liang, Shi-Zhang; Zhang, Shu-Hua; Jiang, Yi-Min; Acta Crystallographica Section E 66 (2010) o3315–; doi:10.1107/S1600536810048075

data_2228286
_publ_section_title
;
 Piperazine-2,3,5,6-tetraone
;
_journal_coeditor_code           DN2617
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o3315
_journal_paper_doi               10.1107/S1600536810048075
_journal_volume                  66
_journal_year                    2010
_chemical_formula_iupac          'C4 H2 N2 O4'
_chemical_formula_moiety         'C4 H2 N2 O4'
_chemical_formula_sum            'C4 H2 N2 O4'
_chemical_formula_weight         142.08
_chemical_name_systematic
;
Piperazine-2,3,5,6-tetraone
;
_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   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 105.25(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   5.1630(10)
_cell_length_b                   8.6220(17)
_cell_length_c                   5.6540(11)
_cell_measurement_reflns_used    438
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25.25
_cell_measurement_theta_min      4.42
_cell_volume                     242.83(9)
_computing_cell_refinement       'XSCANS (Siemens, 1994)'
_computing_data_collection       'XSCANS (Siemens, 1994)'
_computing_data_reduction        'XSCANS (Siemens, 1994)'
_computing_molecular_graphics
;
ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia,
1997) and
PLATON (Spek, 2009)
;
_computing_publication_material  'SHELXTL (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Siemens P4'
_diffrn_measurement_method       \w
_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  0.0241
_diffrn_reflns_av_sigmaI/netI    0.0240
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       -6
_diffrn_reflns_number            1357
_diffrn_reflns_theta_full        25.25
_diffrn_reflns_theta_max         25.25
_diffrn_reflns_theta_min         4.42
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.178
_exptl_absorpt_correction_T_max  0.9779
_exptl_absorpt_correction_T_min  0.9299
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 1996)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.943
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             144
_exptl_crystal_size_max          0.42
_exptl_crystal_size_mid          0.32
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.196
_refine_diff_density_min         -0.207
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.225
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     46
_refine_ls_number_reflns         438
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.225
_refine_ls_R_factor_all          0.0602
_refine_ls_R_factor_gt           0.0477
_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^)+(0.0355P)^2^+0.1147P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0890
_refine_ls_wR_factor_ref         0.0922
_reflns_number_gt                383
_reflns_number_total             438
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            dn2617.cif
_cod_data_source_block           I
_cod_original_cell_volume        242.83(8)
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2228286
_cod_database_fobs_code          2228286