Dipyridinium dichromate: an achiral compound forming chiral crystals
Lennartson, Anders; Håkansson, Mikael; Acta Crystallographica Section C 65 (2009) m182–m184; doi:10.1107/S0108270109011469

data_2017125
_publ_section_title
;
 Dipyridinium dichromate: an achiral compound forming chiral crystals
;
_journal_coeditor_code           SU3032
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              m182
_journal_page_last               m184
_journal_paper_doi               10.1107/S0108270109011469
_journal_volume                  65
_journal_year                    2009
_chemical_formula_iupac          '(C5 H6 N)2 [Cr2 O7]'
_chemical_formula_moiety         '2(C5 H6 N +), Cr2 O7 2-'
_chemical_formula_sum            'C10 H12 Cr2 N2 O7'
_chemical_formula_weight         376.22
_chemical_name_common            'pyridinium dichromate'
_chemical_name_systematic
;
dipyridinium dichromate(VI)
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.2797(17)
_cell_length_b                   12.741(2)
_cell_length_c                   13.371(2)
_cell_measurement_reflns_used    9462
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      25.5
_cell_measurement_theta_min      2.21
_cell_volume                     1410.5(4)
_computing_cell_refinement       'CrystalClear (Rigaku, 2000)'
_computing_data_collection       'CrystalClear (Rigaku, 2000)'
_computing_data_reduction        'CrystalClear (Rigaku, 2000)'
_computing_molecular_graphics
'ORTEP-3 (Farrugia, 1997) and PLUTON (Spek, 2009)'
_computing_publication_material  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SIR92 (Altomare <i>et al.</i>,  1999)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 105
_diffrn_measured_fraction_theta_full 0.953
_diffrn_measured_fraction_theta_max 0.954
_diffrn_measurement_device_type  'Rigaku R-AXIS IIC image-plate system'
_diffrn_measurement_method       \f
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0332
_diffrn_reflns_av_sigmaI/netI    0.0226
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            9462
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.50
_diffrn_reflns_theta_min         2.21
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.573
_exptl_absorpt_correction_T_max  0.8500
_exptl_absorpt_correction_T_min  0.6474
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(CrystalClear; Rigaku, 2000)'
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.762
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             760
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.291
_refine_diff_density_min         -0.336
_refine_ls_abs_structure_details 'Flack (1983), 984 Friedel pairs'
_refine_ls_abs_structure_Flack   0.01(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.058
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     198
_refine_ls_number_reflns         2505
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.058
_refine_ls_R_factor_all          0.0278
_refine_ls_R_factor_gt           0.0259
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[<i>u</i>^2^(Fo^2^)+(0.0359P)^2^+0.8791P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0621
_refine_ls_wR_factor_ref         0.0628
_reflns_number_gt                2441
_reflns_number_total             2505
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            su3032.cif
_cod_data_source_block           I
_cod_database_code               2017125
_cod_database_fobs_code          2017125