Crystal structure of pharmaceutical cocrystals of 2,6-diaminopyridine with piracetam and theophylline.
Durán-Palma, Melissa Hidekel; Mendoza-Barraza, Sonia Sanet; Magaña-Vergara, Nancy Evelyn; Martínez-Martínez, Francisco Javier; González-González, Juan Saulo; Acta crystallographica. Section C, Structural chemistry 73 (2017) 767–772; doi:10.1107/S205322961701230X

data_2311903
_publ_section_title
;
 Crystal structure of pharmaceutical cocrystals of 2,6-diaminopyridine
 with piracetam and theophylline.
;
_journal_coeditor_code           FN3239
_journal_issue                   'Pt 10'
_journal_name_full
'Acta crystallographica. Section C, Structural chemistry'
_journal_page_first              767
_journal_page_last               772
_journal_paper_doi               10.1107/S205322961701230X
_journal_volume                  73
_journal_year                    2017
_chemical_formula_iupac          'C5 H7 N3, C7 H8 N4 O2'
_chemical_formula_moiety         'C5 H7 N3, C7 H8 N4 O2'
_chemical_formula_sum            'C12 H15 N7 O2'
_chemical_formula_weight         289.31
_chemical_name_common
;
2,6-Diaminopyridine--theophylline (1/1)
;
_chemical_name_systematic
;
2,6-Diaminopyridine--1,3-dimethyl-7<i>H</i>-purine-2,6-dione (1/1)
;
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_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_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.4.3
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 109.9270(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.5439(3)
_cell_length_b                   15.6588(5)
_cell_length_c                   9.4887(3)
_cell_measurement_reflns_used    9001
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25.7786
_cell_measurement_theta_min      2.616
_cell_volume                     1333.15(7)
_computing_cell_refinement
;
SAINT (Bruker, 2014)
;
_computing_data_collection
;
APEX2 (Bruker, 2014)
;
_computing_data_reduction
;
SORTAV (Blessing, 1995)
;
_computing_molecular_graphics
;
ORTEP-3 for Windows (Farrugia, 2012)
;
_computing_publication_material
;
WinGX (Farrugia, 2012)
;
_computing_structure_refinement
;
SHELXL97 (Sheldrick, 2008)
;
_computing_structure_solution
;
SIR2004 (Burla <i>et al.</i>,  2005)
;
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device       '\k-geometry diffractometer'
_diffrn_measurement_device_type  'Bruker APEX-II'
_diffrn_measurement_method       '\f or \w oscillation scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.018
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            30803
_diffrn_reflns_reduction_process
;
 Scaled and merged with Sortav
 R.H. Blessing, (1987) Cryst. Rev. 1, 3-58
 R.H. Blessing, (1989) J. Appl. Cryst. 22, 396-397
;
_diffrn_reflns_theta_full        25.81
_diffrn_reflns_theta_max         25.81
_diffrn_reflns_theta_min         2.6
_exptl_absorpt_coefficient_mu    0.105
_exptl_absorpt_correction_T_max  0.745
_exptl_absorpt_correction_T_min  0.704
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(SADABS; Bruker, 2014)
;
_exptl_crystal_colour            grey
_exptl_crystal_density_diffrn    1.441
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             608
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.244
_refine_diff_density_min         -0.182
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.052
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     216
_refine_ls_number_reflns         2564
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.052
_refine_ls_R_factor_all          0.0396
_refine_ls_R_factor_gt           0.0377
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0555P)^2^+0.4344P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1059
_refine_ls_wR_factor_ref         0.1079
_reflns_number_gt                2381
_reflns_number_total             2564
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            fn3239sup1.cif
_cod_data_source_block           monop21c_a
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2311903