Racemic 1-methyl-1,2,4-triazolidine-3,5-dione (1-methylurazole). Definitive characterization of pyramidal hydrazide N atoms and racemate intermolecular hydrogen bonding
Meyers, Cal Y.; Lutfi, Hisham G.; Kolb, Vera M.; Robinson, Paul D.; Acta Crystallographica Section C 50 (1994) 1925–1928; doi:10.1107/S010827019400449X

data_2010271
_publ_section_title
;
 Racemic 1-methyl-1,2,4-triazolidine-3,5-dione (1-methylurazole).
 Definitive characterization of pyramidal hydrazide N atoms and
 racemate intermolecular hydrogen bonding
;
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1925
_journal_page_last               1928
_journal_paper_doi               10.1107/S010827019400449X
_journal_volume                  50
_journal_year                    1994
_chemical_formula_moiety         'C3 H5 N3 O2'
_chemical_formula_sum            'C3 H5 N3 O2'
_chemical_formula_weight         115.09
_chemical_name_common            1-methylurazole
_chemical_name_systematic
;
1-methyl-1,2,4-triazolidine-3,5-dione
;
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_cell_angle_alpha                90.0
_cell_angle_beta                 90.0
_cell_angle_gamma                90.0
_cell_formula_units_Z            4
_cell_length_a                   19.132(2)
_cell_length_b                   6.7170(10)
_cell_length_c                   3.891(2)
_cell_measurement_reflns_used    24
_cell_measurement_temperature    296
_cell_measurement_theta_max      21.8
_cell_measurement_theta_min      19.0
_cell_volume                     500.0(3)
_computing_cell_refinement       'MSC/AFC Diffractometer Control Software'
_computing_data_collection
;
MSC/AFC Diffractometer Control Software (Molecular Structure Corporation,
1988)
;
_computing_data_reduction
;
TEXSAN PROCESS (Molecular Structure Corporation, 1985)
;
_computing_molecular_graphics    'ORTEP (Johnson, 1965) TEXSAN'
_computing_publication_material  'FINISH TEXSAN'
_computing_structure_refinement  'LS TEXSAN'
_computing_structure_solution    'SHELXS86 (Sheldrick, 1985)'
_diffrn_ambient_temperature      296
_diffrn_measurement_device       'Rigaku AFC5S diffractometer'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         x-ray_tube
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.020
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       4
_diffrn_reflns_limit_l_min       -4
_diffrn_reflns_number            997
_diffrn_reflns_theta_max         25
_diffrn_reflns_theta_min         1.75
_diffrn_standards_decay_%        -2.7
_diffrn_standards_interval_count 100
_diffrn_standards_number         3
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.528
_exptl_crystal_description       tabular
_exptl_crystal_F_000             240
_exptl_crystal_size_max          0.43
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.11
_refine_diff_density_min         -0.10
_refine_ls_abs_structure_details
;
The absolute configuration of the structure was not determined.
;
_refine_ls_extinction_coef       0.8E-5(1)
_refine_ls_extinction_method     'Zachariasen (1963) type 2 Gaussian isotropic'
_refine_ls_goodness_of_fit_obs   1.47
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     81
_refine_ls_number_reflns         448
_refine_ls_R_factor_obs          0.026
_refine_ls_shift/esd_max         0.0002
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details     'w = 4F~o~^2^/\s^2^(F~o~^2^)'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_obs         0.032
_reflns_number_observed          448
_reflns_number_total             513
_reflns_observed_criterion       '[I > 3.0\s(I)]'
_cod_data_source_file            cr1122.cif
_cod_data_source_block           default
_cod_depositor_comments
;
The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'w = 4F~o~^2^/\s^2^(F~o~^2^)' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to 'w =
4F~o~^2^/\s^2^(F~o~^2^)'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        500.1(3)
_cod_database_code               2010271