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_7216986
_publ_contact_author
;
Itzia I. Padilla-Mart/'inez
Departamento de Qu/'imica
UPIBI-IPN
Av. Acueducto s/n, Col. Barrio la Laguna Ticoman C.P 07340
M/'exico, D. F.
;
_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         'C16 H17 N5 O6'
_chemical_formula_sum            'C16 H17 N5 O6'
_chemical_formula_weight         375.35
_chemical_name_systematic
; 
N-(3-hydroxypyridine)-N'-(2-nitrophenyl)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                 91.3250(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.2193(4)
_cell_length_b                   14.6988(7)
_cell_length_c                   16.6931(8)
_cell_measurement_temperature    293(2)
_cell_volume                     1770.92(15)
_computing_cell_refinement       'XSCANS (Ver. 2.00)'
_computing_data_collection       'XSCANS (Ver. 2.00)'
_computing_data_reduction        'XSCANS (Ver. 2.00)'
_computing_molecular_graphics    'XPMA (Zsolnai 1997)'
_computing_publication_material  'SHELXL (Sheldrick 1997)'
_computing_structure_refinement  'SHELXL (Sheldrick 1997)'
_computing_structure_solution    'SHELXS (Sheldrick 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measurement_device       'Bruker SMART Area-detector'
_diffrn_measurement_method       'phi and omega 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  0.0513
_diffrn_reflns_av_sigmaI/netI    0.0663
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            11207
_diffrn_reflns_theta_max         26.02
_diffrn_reflns_theta_min         1.85
_exptl_absorpt_coefficient_mu    0.110
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.408
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needles
_exptl_crystal_F_000             784
_exptl_crystal_size_max          .5
_exptl_crystal_size_mid          .4
_exptl_crystal_size_min          .4
_refine_diff_density_max         0.195
_refine_diff_density_min         -0.294
_refine_diff_density_rms         0.037
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.181
_refine_ls_goodness_of_fit_obs   1.589
_refine_ls_hydrogen_treatment    refxyz
_refine_ls_matrix_type           full
_refine_ls_number_parameters     244
_refine_ls_number_reflns         3467
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.181
_refine_ls_restrained_S_obs      1.589
_refine_ls_R_factor_all          0.1061
_refine_ls_R_factor_obs          0.0490
_refine_ls_shift/esd_max         0.000
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1111P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1011
_refine_ls_wR_factor_obs         0.0922
_reflns_number_observed          1720
_reflns_number_total             3467
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            b103063a.txt
_cod_data_source_block           01
_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 
;
_cod_original_cell_volume        1770.9(2)
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               7216986