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_2020333
_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 H7 N2 + , C4 H3 Cl N3 O - , 3C4 H4 Cl N3 O'
_chemical_formula_moiety         'C5 H7 N2+, C4 H3 Cl N3 O-, 3(C4 H4 Cl N3 O)'
_chemical_formula_sum            'C21 H22 Cl4 N14 O4'
_chemical_formula_weight         676.32
_chemical_name_systematic
'(2-aminopyridin-1-ium 2-amino-6-chloro-4-oxo-4<i>H</i>-pyrimidin-3-ide)--[2-amino-6-chloropyrimidin-4(3<i>H</i>)-one] (1/3)'
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                62.633(8)
_cell_angle_beta                 70.877(8)
_cell_angle_gamma                81.182(9)
_cell_formula_units_Z            2
_cell_length_a                   10.8229(11)
_cell_length_b                   11.7395(14)
_cell_length_c                   12.7637(13)
_cell_measurement_reflns_used    11802
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      26.315
_cell_measurement_theta_min      3.32
_cell_volume                     1360.7(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 0.996
_diffrn_measured_fraction_theta_max 0.982
_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  0.1253
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            22097
_diffrn_reflns_theta_full        25.000
_diffrn_reflns_theta_max         25.939
_diffrn_reflns_theta_min         3.326
_exptl_absorpt_coefficient_mu    0.496
_exptl_absorpt_correction_T_max  0.960
_exptl_absorpt_correction_T_min  0.880
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
X-AREA (Stoe & Cie, 2001)
;
_exptl_crystal_colour            colourless
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_exptl_crystal_size_mid          0.092
_exptl_crystal_size_min          0.065
_refine_diff_density_max         0.424
_refine_diff_density_min         -0.434
_refine_ls_extinction_method     none
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_refine_ls_matrix_type           full
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_refine_ls_number_reflns         5228
_refine_ls_number_restraints     14
_refine_ls_restrained_S_all      0.915
_refine_ls_R_factor_all          0.1004
_refine_ls_R_factor_gt           0.0579
_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^)+(0.0722P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1350
_refine_ls_wR_factor_ref         0.1491
_reflns_number_gt                3077
_reflns_number_total             5228
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            uk3121sup1.cif
_cod_data_source_block           Ia
_cod_depositor_comments
;Adding full bibliography for 2020333--2020337.cif.

 Adding full bibliography for 2020333--2020337.cif.
;
_cod_database_code               2020333
_cod_database_fobs_code          2020333
_shelx_estimated_absorpt_t_min   0.882
_shelx_estimated_absorpt_t_max   0.969
_shelxl_version_number           2.013