Importance of Solvent Selection for Stoichiometrically Diverse Cocrystal Systems: Caffeine/Maleic Acid 1:1 and 2:1 Cocrystals
Leyssens, Tom; Springuel, Geraldine; Montis, Riccardo; Candoni, Nadine; Veesler, Stéphane; Crystal Growth & Design 12 (2012) 1520–1530; doi:10.1021/cg201581z

data_4505575
_publ_section_title
;
 Importance of Solvent Selection for Stoichiometrically Diverse Cocrystal
 Systems: Caffeine/Maleic Acid 1:1 and 2:1 Cocrystals
;
_journal_coden_ASTM              CGDEFU
_journal_issue                   3
_journal_name_full               'Crystal Growth & Design'
_journal_page_first              1520
_journal_page_last               1530
_journal_paper_doi               10.1021/cg201581z
_journal_volume                  12
_journal_year                    2012
_chemical_absolute_configuration unk
_chemical_compound_source        'synthesis as described'
_chemical_formula_sum            'C20 H24 N8 O8'
_chemical_formula_weight         504.47
_space_group_IT_number           7
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      7
_symmetry_space_group_name_Hall  'P -2yc'
_symmetry_space_group_name_H-M   'P 1 c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_conform_dict_location     ftp://ftp.iucr.org/pub/cif_core.dic
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.4
_audit_creation_date             2011-03-07T13:24:50-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 97.847(1)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   13.1974(3)
_cell_length_b                   6.9662(2)
_cell_length_c                   26.2816(8)
_cell_measurement_reflns_used    18545
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      28.29
_cell_measurement_theta_min      3.29
_cell_measurement_wavelength     0.71073
_cell_volume                     2393.59(11)
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.954
_diffrn_measured_fraction_theta_max 0.954
_diffrn_measurement_device_type  KappaCCD
_diffrn_measurement_method       'Omega + Phi scan'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.093
_diffrn_reflns_av_unetI/netI     0.0904
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       34
_diffrn_reflns_limit_l_min       -34
_diffrn_reflns_number            18545
_diffrn_reflns_theta_full        28.29
_diffrn_reflns_theta_max         28.29
_diffrn_reflns_theta_min         3.29
_diffrn_standards_number         none
_exptl_absorpt_coefficient_mu    0.111
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.4
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1056
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.305
_refine_diff_density_min         -0.243
_refine_diff_density_rms         0.061
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.032
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     649
_refine_ls_number_reflns         5688
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.2037
_refine_ls_R_factor_gt           0.0973
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1676P)^2^+0.6832P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2465
_refine_ls_wR_factor_ref         0.3191
_reflns_number_gt                2464
_reflns_number_total             5688
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            cg201581z_si_002.cif
_cod_data_source_block           tle001
_cod_original_sg_symbol_H-M      'P c'
_cod_database_code               4505575