Monoclinic polymorph of 3,7-dimethyl-1-(5-oxohexyl)-3,7-dihydro-1<i>H</i>-purine-2,6-dione
Stepanovs, Dmitrijs; Mishnev, Anatoly; Acta Crystallographica Section E 67 (2011) o2851–; doi:10.1107/S1600536811040232

data_2232472
_publ_section_title
;
 Monoclinic polymorph of
 3,7-dimethyl-1-(5-oxohexyl)-3,7-dihydro-1<i>H</i>-purine-2,6-dione
;
_journal_coeditor_code           TK2793
_journal_issue                   11
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o2851
_journal_paper_doi               10.1107/S1600536811040232
_journal_volume                  67
_journal_year                    2011
_chemical_formula_iupac          'C13 H18 N4 O3'
_chemical_formula_moiety         'C13 H18 N4 O3'
_chemical_formula_sum            'C13 H18 N4 O3'
_chemical_formula_weight         278.31
_chemical_melting_point          365
_chemical_name_common            Pentoxifylline
_chemical_name_systematic
;
  3,7-Dimethyl-1-(5-oxohexyl)-3,7-dihydro-1<i>H</i>-purine-2,6-dione
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_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                 90.89(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.743(6)
_cell_length_b                   17.410(8)
_cell_length_c                   7.956(3)
_cell_measurement_reflns_used    6273
_cell_measurement_temperature    190
_cell_measurement_theta_max      27.485
_cell_measurement_theta_min      0.998
_cell_volume                     1349.4(12)
_computing_cell_refinement       'HKL SCALEPACK (Otwinovski & Minor, 1997)'
_computing_data_collection       'KappaCCD Server Software (Nonius, 1997)'
_computing_data_reduction
'HKL DENZO and SCALEPACK (Otwinovski & Minor, 1997)'
_computing_molecular_graphics    'ORTEP-3 (Farrugia, 1997)'
_computing_publication_material  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      190
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.986
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       CCD
_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  0.0533
_diffrn_reflns_av_sigmaI/netI    0.0906
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            5073
_diffrn_reflns_theta_full        27.51
_diffrn_reflns_theta_max         27.51
_diffrn_reflns_theta_min         2.40
_exptl_absorpt_coefficient_mu    0.100
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.370
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             592
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.239
_refine_diff_density_min         -0.203
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.023
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     184
_refine_ls_number_reflns         3065
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.023
_refine_ls_R_factor_all          0.1271
_refine_ls_R_factor_gt           0.0660
_refine_ls_shift/su_max          0.004
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0525P)^2^+0.5672P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1284
_refine_ls_wR_factor_ref         0.1503
_reflns_number_gt                1817
_reflns_number_total             3065
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            tk2793.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2232472
_cod_database_fobs_code          2232472