X-ray crystallographic structures of enamine and amine Schiff bases of pyridoxal and its 1:1 hydrogen-bonded complexes with benzoic acid derivatives: evidence for coupled inter- and intramolecular proton transfer
Sharif, Shasad; Powell, Douglas R.; Schagen, David; Steiner, Thomas; Toney, Michael D.; Fogle, Emily; Limbach, Hans-Heinrich; Acta Crystallographica Section B 62 (2006) 480–487; doi:10.1107/S0108768105040590

data_2100503
_publ_section_title
;
 X-ray crystallographic structures of enamine and amine Schiff bases of
 pyridoxal and its 1:1 hydrogen-bonded complexes with benzoic acid
 derivatives: evidence for coupled inter- and intramolecular proton
 transfer
;
_journal_coeditor_code           SN5027
_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              480
_journal_page_last               487
_journal_paper_doi               10.1107/S0108768105040590
_journal_volume                  62
_journal_year                    2006
_chemical_formula_moiety         'C15 H17 N2 O2, C7 H4 N O4'
_chemical_formula_sum            'C22 H21 N3 O6'
_chemical_formula_weight         423.42
_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                114.88(4)
_cell_angle_beta                 99.61(5)
_cell_angle_gamma                96.03(5)
_cell_formula_units_Z            2
_cell_length_a                   7.683(5)
_cell_length_b                   12.188(6)
_cell_length_c                   12.562(6)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    295(2)
_cell_measurement_theta_max      15.0
_cell_measurement_theta_min      7.0
_cell_volume                     1031.8(11)
_computing_molecular_graphics    'SHELXTL (Sheldrick, 2000)'
_computing_publication_material  'SHELXTL (Sheldrick, 2000)'
_computing_structure_refinement  'SHELXTL (Sheldrick, 2000)'
_computing_structure_solution    'SHELXTL (Sheldrick, 2000)'
_diffrn_ambient_temperature      295(2)
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'Stoe four-circle diffractometer'
_diffrn_measurement_method       \w
_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  0.0176
_diffrn_reflns_av_sigmaI/netI    0.0299
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            3866
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.74
_diffrn_standards_decay_%        3
_diffrn_standards_interval_time  30
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.101
_exptl_absorpt_correction_T_max  0.990
_exptl_absorpt_correction_T_min  0.961
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.363
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             444
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.197
_refine_diff_density_min         -0.205
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.003
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     289
_refine_ls_number_reflns         3591
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.003
_refine_ls_R_factor_all          0.0837
_refine_ls_R_factor_gt           0.0493
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0780P)^2^+0.2500P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1268
_refine_ls_wR_factor_ref         0.1534
_reflns_number_gt                2383
_reflns_number_total             3591
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sn5027.cif
_cod_data_source_block           compound_II_
_cod_original_cell_volume        1031.8(10)
_cod_database_code               2100503