Co-Crystals of Caffeine and Hydroxy-2-naphthoic Acids: Unusual Formation of the Carboxylic Acid Dimer in the Presence of a Heterosynthon
Bučar, Dejan-Krešimir; Henry, Rodger F.; Lou, Xiaochun; Duerst, Richard W.; Borchardt, Thomas B.; MacGillivray, Leonard R.; Zhang, Geoff G. Z.; Molecular Pharmaceutics 4 (2007) 339–; doi:10.1021/mp070004b

data_1505184
_publ_section_title
;
 Co-Crystals of Caffeine and Hydroxy-2-naphthoic Acids:&#x00A0; Unusual
 Formation of the Carboxylic Acid Dimer in the Presence of a Heterosynthon
;
_journal_issue                   3
_journal_name_full               'Molecular Pharmaceutics'
_journal_page_first              339
_journal_paper_doi               10.1021/mp070004b
_journal_volume                  4
_journal_year                    2007
_chemical_formula_moiety         'C8 H10 N4 O2, C11 H8 O3'
_chemical_formula_sum            'C19 H18 N4 O5'
_chemical_formula_weight         382.37
_chemical_melting_point          'caffeine 6-hydroxy-2-naphthoic acid'
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                106.475(5)
_cell_angle_beta                 98.162(5)
_cell_angle_gamma                104.904(6)
_cell_formula_units_Z            2
_cell_length_a                   8.029(3)
_cell_length_b                   8.592(3)
_cell_length_c                   13.996(5)
_cell_measurement_reflns_used    924
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      28.063
_cell_measurement_theta_min      2.548
_cell_volume                     870.3(5)
_computing_cell_refinement       'Bruker saintplus (Bruker 1999)'
_computing_data_collection       'Bruker SMART (Bruker 2001)'
_computing_data_reduction        'Bruker saintplus (Bruker 1999)'
_computing_structure_refinement  'SHELXL (Sheldrick, 2000)'
_computing_structure_solution    'SHELXL (Sheldrick, 2000)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.970
_diffrn_measured_fraction_theta_max 0.970
_diffrn_measurement_device_type  'Bruker APEX CCD'
_diffrn_measurement_method       'omega scan'
_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  0.0804
_diffrn_reflns_av_sigmaI/netI    0.0609
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            10422
_diffrn_reflns_theta_full        28.27
_diffrn_reflns_theta_max         28.27
_diffrn_reflns_theta_min         1.56
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.108
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.459
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       fragment
_exptl_crystal_F_000             400
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.371
_refine_diff_density_min         -0.198
_refine_diff_density_rms         0.051
_refine_ls_extinction_coef       0.0024(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.530
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     303
_refine_ls_number_reflns         4196
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.530
_refine_ls_R_factor_all          0.0757
_refine_ls_R_factor_gt           0.0605
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1149
_refine_ls_wR_factor_ref         0.1187
_reflns_number_gt                3270
_reflns_number_total             4196
_reflns_threshold_expression     I>2sigma(I)
_cod_data_source_file            mp070004bsi20070105_112248.cif
_cod_data_source_block           crystal_C
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               1505184