Two tautomeric polymorphs of 2,6-dichloropurine
García-Rubiño, M. Eugenia; Choquesillo-Lazarte, Duane; Núñez, M. C.; Campos, Joaquín M.; Acta Crystallographica Section C 67 (2011) o484–o486; doi:10.1107/S0108270111043575

data_2018322
_publ_section_title
;
 Two tautomeric polymorphs of 2,6-dichloropurine
;
_journal_coeditor_code           GG3264
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o484
_journal_page_last               o486
_journal_paper_doi               10.1107/S0108270111043575
_journal_volume                  67
_journal_year                    2011
_chemical_formula_iupac          'C5 H2 Cl2 N4'
_chemical_formula_moiety         'C5 H2 Cl2 N4'
_chemical_formula_sum            'C5 H2 Cl2 N4'
_chemical_formula_weight         189.01
_chemical_name_systematic
;
2,6-dichloro-9<i>H</i>-purine
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
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_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
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_cell_angle_alpha                90.00
_cell_angle_beta                 115.381(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
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_cell_length_b                   9.4898(7)
_cell_length_c                   12.2656(9)
_cell_measurement_reflns_used    2440
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      64.99
_cell_measurement_theta_min      3.47
_cell_volume                     1481.4(2)
_computing_cell_refinement       'SAINT (Bruker, 2010)'
_computing_data_collection       'APEX2 (Bruker, 2010)'
_computing_data_reduction        'SAINT (Bruker, 2010)'
_computing_molecular_graphics    'PLATON (Spek, 2009)'
_computing_publication_material  'publCIF (Westrip, 2010)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.985
_diffrn_measured_fraction_theta_max 0.985
_diffrn_measurement_device_type  'Bruker X8 Proteum'
_diffrn_measurement_method       '\f and \w'
_diffrn_radiation_monochromator  'graded multilayer optics'
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_diffrn_radiation_type           CuK\a
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_diffrn_reflns_theta_min         5.82
_diffrn_standards_decay_%        0
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_exptl_absorpt_correction_T_max  0.7529
_exptl_absorpt_correction_T_min  0.3767
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_exptl_absorpt_process_details   '(SADABS; Bruker, 2001)'
_exptl_crystal_colour            colourless
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_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'cut block'
_exptl_crystal_F_000             752
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_refine_diff_density_min         -0.289
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_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^)+(0.0735P)^2^+0.6074P] where P=(Fo^2^+2Fc^2^)/3'
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_cod_database_code               2018322
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