2-Ethyl-5<i>H</i>-1,3,4-thiadiazolo[3,2-<i>a</i>]pyrimidin-5-one
da Silva, Luiz Everson; Joussef, Antonio Carlos; Foro, Sabine; Acta Crystallographica Section E 63 (2007) o412–o413; doi:10.1107/S1600536806054584

data_2211714
_publ_section_title
;
 2-Ethyl-5<i>H</i>-1,3,4-thiadiazolo[3,2-<i>a</i>]pyrimidin-5-one
;
_journal_coeditor_code           AT2191
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o412
_journal_page_last               o413
_journal_paper_doi               10.1107/S1600536806054584
_journal_volume                  63
_journal_year                    2007
_chemical_formula_iupac          'C7 H7 N3 O S'
_chemical_formula_moiety         'C7 H7 N3 O S'
_chemical_formula_sum            'C7 H7 N3 O S'
_chemical_formula_weight         181.22
_chemical_name_systematic
;
2-Ethyl-5H-1,3,4-thiadiazolo[3,2-a]pyrimidin-5-one
;
_space_group_IT_number           148
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  '-R 3'
_symmetry_space_group_name_H-M   'R -3 :H'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            18
_cell_length_a                   32.347(5)
_cell_length_b                   32.347(5)
_cell_length_c                   4.0784(7)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    299(2)
_cell_measurement_theta_max      22.44
_cell_measurement_theta_min      2.72
_cell_volume                     3695.6(10)
_computing_cell_refinement       CAD-4-P
_computing_data_collection       'CAD-4-PC (Enraf--Nonius, 1996)'
_computing_data_reduction        'REDU4 (Stoe & Cie, 1987)'
_computing_molecular_graphics    'PLATON (Spek, 2003)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      299(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Enraf--Nonius CAD-4'
_diffrn_measurement_method       \w/2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54180
_diffrn_reflns_av_R_equivalents  0.0336
_diffrn_reflns_av_sigmaI/netI    0.0266
_diffrn_reflns_limit_h_max       1
_diffrn_reflns_limit_h_min       -38
_diffrn_reflns_limit_k_max       38
_diffrn_reflns_limit_k_min       -33
_diffrn_reflns_limit_l_max       0
_diffrn_reflns_limit_l_min       -4
_diffrn_reflns_number            2610
_diffrn_reflns_theta_full        67.02
_diffrn_reflns_theta_max         67.02
_diffrn_reflns_theta_min         2.73
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    3.130
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.466
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1692
_exptl_crystal_size_max          0.48
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.28
_refine_diff_density_max         0.174
_refine_diff_density_min         -0.217
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.114
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     109
_refine_ls_number_reflns         1461
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.114
_refine_ls_R_factor_all          0.0416
_refine_ls_R_factor_gt           0.0358
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0354P)^2^+5.1533P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0931
_refine_ls_wR_factor_ref         0.0957
_reflns_number_gt                1300
_reflns_number_total             1461
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            at2191.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'R -3'
_cod_database_code               2211714
_cod_database_fobs_code          2211714