Synthon-driven polymorphism in the favipiravir–theophylline cocrystal
Kuri, Prasitaditya; Nanubolu, Jagadeesh Babu; CrystEngComm  (2026) –; doi:10.1039/D6CE00187D

data_7251894
_publ_section_title
;
 Synthon-driven polymorphism in the favipiravir--theophylline cocrystal
;
_journal_issue                   17
_journal_name_full               CrystEngComm
_journal_page_first              2721
_journal_page_last               2735
_journal_paper_doi               10.1039/D6CE00187D
_journal_volume                  28
_journal_year                    2026
_chemical_formula_moiety         'C7 H8 N4 O2, C5 H4 F N3 O2'
_chemical_formula_sum            'C12 H12 F N7 O4'
_chemical_formula_weight         337.29
_chemical_name_systematic        'Favipiravir Theophylline Cocrystal Form II'
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_atom_sites_solution_hydrogens   mixed
_audit_creation_method           SHELXL-2019/3
_audit_update_record
;
2025-12-03 deposited with the CCDC.	2026-04-01 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 95.548(19)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.228(5)
_cell_length_b                   13.950(10)
_cell_length_c                   14.273(12)
_cell_measurement_reflns_used    9975
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      30.581
_cell_measurement_theta_min      2.195
_cell_volume                     1432.4(19)
_computing_cell_refinement       '<i>SAINT</i> (Bruker, 2016)'
_computing_data_collection       '<i>APEX3</i> (Bruker, 2016)'
_computing_data_reduction        'Bruker SAINT'
_computing_structure_refinement  'SHELXL-2019/2 (Sheldrick, 2019)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker D8 QUEST PHOTON-100'
_diffrn_measurement_method       '\w and \f'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0365
_diffrn_reflns_av_unetI/netI     0.0217
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            28742
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.499
_diffrn_reflns_theta_min         2.831
_diffrn_source                   microfocus
_exptl_absorpt_coefficient_mu    0.130
_exptl_absorpt_correction_T_max  0.7461
_exptl_absorpt_correction_T_min  0.7129
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS 2014/5'
_exptl_crystal_colour            COLOURLESS
_exptl_crystal_density_diffrn    1.564
_exptl_crystal_description       NEEDLE
_exptl_crystal_F_000             696
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: Ethanol'
_exptl_crystal_size_max          0.330
_exptl_crystal_size_mid          0.280
_exptl_crystal_size_min          0.140
_refine_diff_density_max         0.255
_refine_diff_density_min         -0.216
_refine_diff_density_rms         0.044
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.078
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     235
_refine_ls_number_reflns         3284
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.078
_refine_ls_R_factor_all          0.0569
_refine_ls_R_factor_gt           0.0460
_refine_ls_shift/su_max          0.008
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0529P)^2^+0.7101P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1194
_refine_ls_wR_factor_ref         0.1268
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2699
_reflns_number_total             3284
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6ce00187d2.cif
_cod_data_source_block           ka996_0m-auto_pl
_cod_depositor_comments
'Adding full bibliography for 7251893--7251894.cif.'
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               7251894
_shelx_shelxl_version_number     2019/3
_shelx_estimated_absorpt_t_min   0.958
_shelx_estimated_absorpt_t_max   0.982
_shelx_res_checksum              996