Variable Temperature Neutron Diffraction Analysis of a Very Short O−H···O Hydrogen Bond in 2,3,5,6-Pyrazinetetracarboxylic Acid Dihydrate: Synthon-Assisted Short Oacid−H···OwaterHydrogen Bonds in a Multicenter Array
Vishweshwar, Peddy; Jagadeesh Babu, N.; Nangia, Ashwini; Mason, Sax A.; Puschmann, Horst; Mondal, Raju; Howard, Judith A. K.; The Journal of Physical Chemistry A 108 (2004) 9406–; doi:10.1021/jp0476848

data_1506838
_publ_section_title
;
 Variable Temperature Neutron Diffraction Analysis of a Very Short
 O&#x2212;H&#x00B7;&#x00B7;&#x00B7;O Hydrogen Bond in
 2,3,5,6-Pyrazinetetracarboxylic Acid Dihydrate:&#x00A0; Synthon-Assisted
 Short Oacid&#x2212;H&#x00B7;&#x00B7;&#x00B7;OwaterHydrogen Bonds in a
 Multicenter Array
;
_journal_issue                   43
_journal_name_full               'The Journal of Physical Chemistry A'
_journal_page_first              9406
_journal_paper_doi               10.1021/jp0476848
_journal_volume                  108
_journal_year                    2004
_chemical_formula_moiety         C7H4N2O6.2H2O
_chemical_formula_sum            'C7 H8 N2 O8'
_chemical_formula_weight         248.15
_chemical_melting_point          457
_chemical_name_common            '2,3,5-Pyrazine tricarboxylic acid dihydrate'
_chemical_name_systematic
; 
 2,3,5-Pyrazine tricarboxylic acid dihydrate
;
_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                93.064(2)
_cell_angle_beta                 90.513(2)
_cell_angle_gamma                103.009(2)
_cell_formula_units_Z            2
_cell_length_a                   5.2830(3)
_cell_length_b                   6.6497(3)
_cell_length_c                   13.8423(7)
_cell_measurement_reflns_used    3993
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      27.482
_cell_measurement_theta_min      2.943
_cell_volume                     473.02(4)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      120(2)
_diffrn_detector_area_resol_mean 8
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'SMART6K CCD area detector'
_diffrn_measurement_method       '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  0.0515
_diffrn_reflns_av_sigmaI/netI    0.0320
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            7415
_diffrn_reflns_theta_full        27.49
_diffrn_reflns_theta_max         27.49
_diffrn_reflns_theta_min         1.47
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    0.163
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.742
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Plate
_exptl_crystal_F_000             256
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.306
_refine_diff_density_min         -0.286
_refine_diff_density_rms         0.069
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.043
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     186
_refine_ls_number_reflns         2172
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.043
_refine_ls_R_factor_all          0.0381
_refine_ls_R_factor_gt           0.0331
_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^)+(0.0583P)^2^+0.0888P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0937
_refine_ls_wR_factor_ref         0.0981
_reflns_number_gt                1887
_reflns_number_total             2172
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            jp0476848si20040528_030807.cif
_cod_data_source_block           03rmd154
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
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 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_formula_sum        C7H8N2O8
_cod_database_code               1506838