Tetraprotonated Tetra(2-pyridyl)pyrazine: Pyrazine-2,3,5,6-tetra(2-pyridinium) Tetrachloride Dihydrate
Graf, M.; Stoeckli-Evans, H.; Acta Crystallographica Section C 52 (1996) 3073–3075; doi:10.1107/S0108270196010943

data_2005779
_publ_section_title
;
 Tetraprotonated Tetra(2-pyridyl)pyrazine:
 Pyrazine-2,3,5,6-tetra(2-pyridinium) Tetrachloride Dihydrate
;
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              3073
_journal_page_last               3075
_journal_paper_doi               10.1107/S0108270196010943
_journal_volume                  52
_journal_year                    1996
_chemical_formula_iupac          '[C24 H20 N6] 4+ , 4Cl - , 2H2 O'
_chemical_formula_sum            'C24 H24 Cl4 N6 O2'
_chemical_formula_weight         570.29
_chemical_name_systematic
;
 Tetra(2-pyridinium)pyrazine-tetrachloride-dihydrate
;
_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'
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 101.70(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   6.284(1)
_cell_length_b                   23.510(1)
_cell_length_c                   9.033(1)
_cell_measurement_reflns_used    21
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      19
_cell_measurement_theta_min      14
_cell_volume                     1306.8(3)
_computing_cell_refinement       DIF4
_computing_data_collection       'DIF4 (Stoe & Cie, 1993)'
_computing_data_reduction        'REDU4 (Stoe & Cie, 1993)'
_computing_molecular_graphics    'PLUTON (Spek, 1993)'
_computing_publication_material  SHELXS86
_computing_structure_refinement  'SHELXL93 (Sheldrick, 1993)'
_computing_structure_solution    'SHELXS86 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measurement_device       'Stoe AED2 4-circle'
_diffrn_measurement_method       2\Q/\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    0.0234
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       27
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            2282
_diffrn_reflns_theta_max         25.0
_diffrn_reflns_theta_min         1.73
_diffrn_standards_decay_%        1.5
_diffrn_standards_interval_time  60
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    0.488
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.449
_exptl_crystal_density_meas      ?
_exptl_crystal_description       plates
_exptl_crystal_F_000             588
_exptl_crystal_size_max          0.46
_exptl_crystal_size_mid          0.34
_exptl_crystal_size_min          0.11
_refine_diff_density_max         0.226
_refine_diff_density_min         -0.206
_refine_ls_extinction_coef       0.0047(11)
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_all   1.108
_refine_ls_goodness_of_fit_obs   1.075
_refine_ls_matrix_type           full
_refine_ls_number_parameters     180
_refine_ls_number_reflns         2276
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.127
_refine_ls_restrained_S_obs      1.075
_refine_ls_R_factor_all          0.0505
_refine_ls_R_factor_obs          0.0323
_refine_ls_shift/esd_max         0.061
_refine_ls_shift/esd_mean        0.007
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0392P)^2^+0.6839P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0955
_refine_ls_wR_factor_obs         0.0800
_reflns_number_observed          1798
_reflns_number_total             2282
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            jz1156.cif
_cod_data_source_block           tppzhcl
_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 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'none' 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 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc w =
1/[\s^2^(Fo^2^)+(0.0392P)^2^+0.6839P] 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^)+(0.0392P)^2^+0.6839P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2005779