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_2020334
_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
'2C5 H7 N2 + , 2C4 H3 Cl N3 O - , 10C4 H4 Cl N3 O , C5 H6 N2'
_chemical_formula_moiety
'2(C5 H7 N2+), 2(C4 H3 Cl N3 O-), 10(C4 H4 Cl N3 O), C5 H6 N2'
_chemical_formula_sum            'C63 H66 Cl12 N42 O12'
_chemical_formula_weight         2028.97
_chemical_name_systematic
'bis-(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]--2-aminopyridine (2/10/1)'
_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                83.774(4)
_cell_angle_beta                 84.000(4)
_cell_angle_gamma                83.554(4)
_cell_formula_units_Z            2
_cell_length_a                   14.0097(7)
_cell_length_b                   14.0185(7)
_cell_length_c                   21.4229(11)
_cell_measurement_reflns_used    38798
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      26.945
_cell_measurement_theta_min      1.67
_cell_volume                     4137.9(4)
_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 1.000
_diffrn_measured_fraction_theta_max 0.992
_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  0.0264
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            20468
_diffrn_reflns_theta_full        25.000
_diffrn_reflns_theta_max         26.409
_diffrn_reflns_theta_min         1.675
_exptl_absorpt_coefficient_mu    0.489
_exptl_absorpt_correction_T_max  0.980
_exptl_absorpt_correction_T_min  0.890
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
X-AREA (Stoe & Cie, 2001)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.628
_exptl_crystal_description       needle
_exptl_crystal_F_000             2076
_exptl_crystal_size_max          0.240
_exptl_crystal_size_mid          0.095
_exptl_crystal_size_min          0.035
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_refine_diff_density_min         -1.228
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.082
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_refine_ls_number_parameters     1350
_refine_ls_number_reflns         16871
_refine_ls_number_restraints     313
_refine_ls_restrained_S_all      1.072
_refine_ls_R_factor_all          0.1692
_refine_ls_R_factor_gt           0.1358
_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^)+(0.1287P)^2^+31.8979P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.3639
_refine_ls_wR_factor_ref         0.3786
_reflns_number_gt                10620
_reflns_number_total             16871
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            uk3121sup1.cif
_cod_data_source_block           Ib
_cod_depositor_comments
;Adding full bibliography for 2020333--2020337.cif.

 Adding full bibliography for 2020333--2020337.cif.
;
_cod_database_code               2020334
_cod_database_fobs_code          2020334
_shelx_estimated_absorpt_t_min   0.892
_shelx_estimated_absorpt_t_max   0.983
_shelxl_version_number           2.013