Mechanochemical synthesis of pyrazine:dicarboxylic acid cocrystals and a study of dissociation by quantitative phase analysis
Arhangelskis, Mihails; Lloyd, Gareth O.; Jones, William; CrystEngComm 14 (2012) 5203–; doi:10.1039/c2ce25121c

data_7208188
_publ_section_title
;
 Mechanochemical synthesis of pyrazine:dicarboxylic acid cocrystals and a
 study of dissociation by quantitative phase analysis
;
_journal_issue                   16
_journal_name_full               CrystEngComm
_journal_page_first              5203
_journal_paper_doi               10.1039/c2ce25121c
_journal_volume                  14
_journal_year                    2012
_chemical_formula_moiety         'C4 H4 O4, C4 H4 N2 '
_chemical_formula_sum            'C8 H8 N2 O4'
_chemical_formula_weight         196.16
_chemical_name_common            'Fumaric acid:Pyrazine cocrystal'
_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                85.396(11)
_cell_angle_beta                 82.199(12)
_cell_angle_gamma                85.176(11)
_cell_formula_units_Z            1
_cell_length_a                   5.1006(7)
_cell_length_b                   6.1168(8)
_cell_length_c                   6.9894(10)
_cell_measurement_reflns_used    531
_cell_measurement_temperature    120
_cell_measurement_theta_max      30.4280
_cell_measurement_theta_min      2.9429
_cell_volume                     214.76(5)
_computing_cell_refinement
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.34.44 (release 25-10-2010 CrysAlis171 .NET)
(compiled Oct 25 2010,18:11:34)
;
_computing_data_collection
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.34.44 (release 25-10-2010 CrysAlis171 .NET)
(compiled Oct 25 2010,18:11:34)
;
_computing_data_reduction
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.34.44 (release 25-10-2010 CrysAlis171 .NET)
(compiled Oct 25 2010,18:11:34)
;
_computing_molecular_graphics    Xseed
_computing_publication_material  Xseed
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      120
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Xcalibur, Eos, Gemini ultra'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Enhance (Mo) X-ray Source'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.7107
_diffrn_reflns_av_R_equivalents  0.0249
_diffrn_reflns_av_sigmaI/netI    0.0680
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            1627
_diffrn_reflns_theta_full        28.00
_diffrn_reflns_theta_max         28.00
_diffrn_reflns_theta_min         2.95
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.124
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.60239
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.34.44 (release 25-10-2010 CrysAlis171 .NET)
(compiled Oct 25 2010,18:11:34)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.517
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             102
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.21
_refine_diff_density_max         0.346
_refine_diff_density_min         -0.387
_refine_diff_density_rms         0.067
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.068
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     68
_refine_ls_number_reflns         1030
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.068
_refine_ls_R_factor_all          0.0880
_refine_ls_R_factor_gt           0.0591
_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^)+(0.0607P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1271
_refine_ls_wR_factor_ref         0.1521
_reflns_number_gt                732
_reflns_number_total             1030
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2ce25121c.txt
_cod_data_source_block           1
_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 1891 2012-01-12 08:04:46Z andrius 
;
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7208188