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_2100504
_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         'C9 H12 N2 O2'
_chemical_formula_sum            'C9 H12 N2 O2'
_chemical_formula_weight         180.21
_space_group_IT_number           14
_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_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 106.728(5)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.046(2)
_cell_length_b                   4.8739(8)
_cell_length_c                   18.027(3)
_cell_measurement_reflns_used    2559
_cell_measurement_temperature    295(2)
_cell_measurement_theta_max      26.00
_cell_measurement_theta_min      2.31
_cell_volume                     929.5(3)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_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 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker APEX'
_diffrn_measurement_method       '\w scans'
_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  0.0182
_diffrn_reflns_av_sigmaI/netI    0.0158
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            7547
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         2.36
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.093
_exptl_absorpt_correction_T_max  0.996
_exptl_absorpt_correction_T_min  0.942
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 2002)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.288
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             384
_exptl_crystal_size_max          0.45
_exptl_crystal_size_mid          0.23
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.202
_refine_diff_density_min         -0.151
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.022
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     124
_refine_ls_number_reflns         1814
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.022
_refine_ls_R_factor_all          0.0570
_refine_ls_R_factor_gt           0.0507
_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^)+(0.0810P)^2^+0.2100P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1419
_refine_ls_wR_factor_ref         0.1472
_reflns_number_gt                1575
_reflns_number_total             1814
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sn5027.cif
_cod_data_source_block           compound_III_
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2100504