Further insight into three center hydrogen bonding. Participation in tautomeric equilibria of heterocyclic amides
Padilla-Martínez, Itzia I.; Martínez-Martínez, Francisco J.; García-Báez, Efrén V.; Torres-Valencia, J. Martín; Rojas-Lima, Susana; Höpfl, Herbert; Journal of the Chemical Society, Perkin Transactions 2  (2001) 1817–; doi:10.1039/b103063a

data_7216987
_publ_contact_author             'Itzia I. Padilla-Martinez'
_publ_section_title
;
 Further insight into three center hydrogen bonding. Participation in
 tautomeric equilibria of heterocyclic amides
;
_journal_issue                   9
_journal_name_full
'Journal of the Chemical Society, Perkin Transactions 2'
_journal_page_first              1817
_journal_paper_doi               10.1039/b103063a
_journal_year                    2001
_chemical_formula_moiety         'C14 H15 N3 O5'
_chemical_formula_sum            'C14 H15 N3 O5'
_chemical_formula_weight         305.29
_chemical_name_systematic
; 
N-(3-hydroxypyridine)-N'-(2-methoxyphenyl)oxamide
;
_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-CIF-file updated by CIFRTF'
_cell_angle_alpha                90.00
_cell_angle_beta                 101.02(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   12.825(3)
_cell_length_b                   15.110(3)
_cell_length_c                   7.3410(10)
_cell_measurement_reflns_used    24
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25
_cell_measurement_theta_min      1
_cell_volume                     1396.3(5)
_computing_cell_refinement       'CAD4 software (Enraf-Nonius, 1989)'
_computing_data_collection       'CAD4 software (Enraf-Nonius, 1989)'
_computing_data_reduction        'JANA98 (Petricek Vaclav, 1998)'
_computing_molecular_graphics    'XPMA (Zsolnai 1997)'
_computing_publication_material  'SHELXL-97 (Sheldrick 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick 1997)'
_computing_structure_solution    'SHELXS-97(Sheldrick 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measurement_device       Enraf-Nonius
_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  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0359
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            2825
_diffrn_reflns_theta_max         26.29
_diffrn_reflns_theta_min         2.70
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 100
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.112
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.452
_exptl_crystal_description       prism
_exptl_crystal_F_000             640
_exptl_crystal_size_max          .48
_exptl_crystal_size_mid          .224
_exptl_crystal_size_min          .112
_refine_diff_density_max         0.233
_refine_diff_density_min         -0.317
_refine_diff_density_rms         0.045
_refine_ls_extinction_coef       0.0000(12)
_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_all   1.014
_refine_ls_goodness_of_fit_obs   1.141
_refine_ls_hydrogen_treatment    'Riding model, fixed isotropic U'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     200
_refine_ls_number_reflns         2824
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.024
_refine_ls_restrained_S_obs      1.141
_refine_ls_R_factor_all          0.0756
_refine_ls_R_factor_obs          0.0399
_refine_ls_shift/esd_max         -1.755
_refine_ls_shift/esd_mean        0.011
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0634P)^2^+0.3217P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1248
_refine_ls_wR_factor_obs         0.1118
_reflns_number_observed          1892
_reflns_number_total             2825
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            b103063a.txt
_cod_data_source_block           a61
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to
/usr/data/users/saulius/automatic-downloads/retrospective/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0634P)^2^+0.3217P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.0634P)^2^+0.3217P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 

The following automatic conversions were performed:

'_atom_sites_solution_primary' value 'direct methods' was changed to
'direct'.

'_atom_sites_solution_hydrogens' value 'geometrically' was changed to
'geom'.

Automatic conversion script
Id: cif_fix_values 6452 2018-10-05 10:23:21Z andrius 
;
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               7216987