6-Chloroisocytosine and 5-bromo-6-methylisocytosine: again, one or two tautomers present in the same crystal?
Gerhardt, Valeska; Bolte, Michael; Acta Crystallographica Section C 72 (2016) 84–93; doi:10.1107/S2053229615024080

data_2020335
_publ_section_title
;
 6-Chloroisocytosine and 5-bromo-6-methylisocytosine: again, one or two
 tautomers present in the same crystal?
;
_journal_coeditor_code           UK3121
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              84
_journal_page_last               93
_journal_paper_doi               10.1107/S2053229615024080
_journal_volume                  72
_journal_year                    2016
_chemical_formula_iupac          'C5 H6 Br N3 O'
_chemical_formula_moiety         'C5 H6 Br N3 O'
_chemical_formula_sum            'C5 H6 Br N3 O'
_chemical_formula_weight         204.04
_chemical_name_systematic
'2-amino-5-bromo-6-methylpyrimidin-4(3<i>H</i>)-one--2-amino-5-bromo-6-methylpyrimidin-4(1<i>H</i>)-one (1/1)'
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                90
_cell_angle_beta                 108.021(11)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   9.8154(13)
_cell_length_b                   9.9532(8)
_cell_length_c                   14.344(2)
_cell_measurement_reflns_used    6792
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      26.125
_cell_measurement_theta_min      3.625
_cell_volume                     1332.6(3)
_computing_cell_refinement
;
X-AREA (Stoe & Cie, 2001)
;
_computing_data_collection
;
X-AREA (Stoe & Cie, 2001)
;
_computing_data_reduction
;
X-AREA (Stoe & Cie, 2001)
;
_computing_molecular_graphics
;
Mercury (Macrae <i>et al.</i>,  2008) and XP in SHELXTL-Plus (Sheldrick,
2008)
;
_computing_publication_material
;
publCIF (Westrip, 2010)
;
_computing_structure_refinement
;
SHELXL97 (Sheldrick, 2008)
;
_computing_structure_solution
;
SHELXS97 (Sheldrick, 2008)
;
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.983
_diffrn_measurement_device_type  'Stoe IPDSII two-circle diffractometer'
_diffrn_measurement_method       \w
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1034
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            6144
_diffrn_reflns_theta_full        25.000
_diffrn_reflns_theta_max         25.690
_diffrn_reflns_theta_min         3.621
_exptl_absorpt_coefficient_mu    6.095
_exptl_absorpt_correction_T_max  0.310
_exptl_absorpt_correction_T_min  0.220
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
X-AREA (Stoe & Cie, 2001)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    2.034
_exptl_crystal_description       block
_exptl_crystal_F_000             800
_exptl_crystal_size_max          0.350
_exptl_crystal_size_mid          0.300
_exptl_crystal_size_min          0.250
_refine_diff_density_max         1.064
_refine_diff_density_min         -1.499
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.078
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     201
_refine_ls_number_reflns         2480
_refine_ls_number_restraints     11
_refine_ls_restrained_S_all      1.076
_refine_ls_R_factor_all          0.0912
_refine_ls_R_factor_gt           0.0762
_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^)+(0.1394P)^2^+4.5450P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2178
_refine_ls_wR_factor_ref         0.2283
_reflns_number_gt                1986
_reflns_number_total             2480
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            uk3121sup1.cif
_cod_data_source_block           II
_cod_depositor_comments
;Adding full bibliography for 2020333--2020337.cif.

 Adding full bibliography for 2020333--2020337.cif.
;
_cod_database_code               2020335
_cod_database_fobs_code          2020335
_shelx_estimated_absorpt_t_min   0.224
_shelx_estimated_absorpt_t_max   0.311
_shelxl_version_number           2.013