3-Bromo-1-(2-deoxy-β-<small>D</small>-<i>erythro</i>-pentofuranosyl)-1<i>H</i>-pyrazolo[3,4-<i>d</i>]pyrimidine-4,6-diamine: a nucleoside which strongly enhances DNA duplex stability
Seela, Frank; Sirivolu, Venkata Ramana; He, Junlin; Eickmeier, Henning; Acta Crystallographica Section C 61 (2005) o67–o69; doi:10.1107/S0108270104032123

data_2014722
_publ_section_title
;3-Bromo-1-(2-deoxy-\b-<small>D</small>-<i>erythro</i>-pentofuranosyl)-1<i>H</i>-pyrazolo[3,4-<i>d</i>]pyrimidine-4,6-diamine:
 a nucleoside which strongly enhances DNA duplex stability
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o67
_journal_page_last               o69
_journal_paper_doi               10.1107/S0108270104032123
_journal_volume                  61
_journal_year                    2005
_chemical_formula_iupac          'C10 H13 Br N6 O3'
_chemical_formula_moiety         'C10 H13 Br N6 O3'
_chemical_formula_sum            'C10 H13 Br N6 O3'
_chemical_formula_weight         345.17
_chemical_name_systematic
;
3-Bromo-1-(2-deoxy-\b-D-erythro-pentofuranosyl)-1H-
pyrazolo[3,4-d]pyrimidine-4,6-diamine
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.5939(10)
_cell_length_b                   9.2822(18)
_cell_length_c                   18.164(2)
_cell_measurement_reflns_used    42
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      12.49
_cell_measurement_theta_min      4.99
_cell_volume                     1280.3(3)
_computing_cell_refinement       XSCANS
_computing_data_collection       'XSCANS (Siemens, 1996)'
_computing_data_reduction        'SHELXTL (Sheldrick, 1997)'
_computing_molecular_graphics    SHELXTL
_computing_publication_material
'SHELXTL (Sheldrick, 1997) and PLATON (Spek, 1999)'
_computing_structure_refinement  SHELXTL
_computing_structure_solution    SHELXTL
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker P4'
_diffrn_measurement_method       '2\q/\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0423
_diffrn_reflns_av_sigmaI/netI    0.0695
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            4231
_diffrn_reflns_theta_full        30.00
_diffrn_reflns_theta_max         30.00
_diffrn_reflns_theta_min         2.24
_diffrn_standards_decay_%        none
_diffrn_standards_interval_count 97
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    3.230
_exptl_absorpt_correction_T_max  0.5194
_exptl_absorpt_correction_T_min  0.3155
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   '(SHELXTL; Sheldrick,1997)'
_exptl_crystal_colour            'light brown'
_exptl_crystal_density_diffrn    1.791
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'transparent plate'
_exptl_crystal_F_000             696
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.28
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.443
_refine_diff_density_min         -0.887
_refine_ls_abs_structure_details 'Flack (1983), 1536 Friedel pairs?'
_refine_ls_abs_structure_Flack   0.020(16)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.065
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     199
_refine_ls_number_reflns         3682
_refine_ls_number_restraints     8
_refine_ls_restrained_S_all      1.064
_refine_ls_R_factor_all          0.0909
_refine_ls_R_factor_gt           0.0563
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0688P)^2^+0.0128P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1224
_refine_ls_wR_factor_ref         0.1394
_reflns_number_gt                2568
_reflns_number_total             3682
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sk1785.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P21 21 21'
_cod_database_code               2014722
_cod_database_fobs_code          2014722