Rare examples of base pairing <i>via</i> a protonated pyridine N atom in two salts of <i>N</i>^2^,<i>N</i>^6^-bis(1,3-dimethylimidazolin-2-ylidene)pyridine-2,6-diamine
Neuba, Adam; Akin, Enver; Herres-Pawlis, Sonja; Flörke, Ulrich; Henkel, Gerald; Acta Crystallographica Section C 64 (2008) m194–m197; doi:10.1107/S0108270108007567

data_2016582
_publ_section_title
;Rare examples of base pairing <i>via</i> a protonated pyridine N atom in two
 salts of
 <i>N</i>^2^,<i>N</i>^6^-bis(1,3-dimethylimidazolin-2-ylidene)pyridine-2,6-diamine
;
_journal_coeditor_code           EM3010
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              m194
_journal_page_last               m197
_journal_paper_doi               10.1107/S0108270108007567
_journal_volume                  64
_journal_year                    2008
_chemical_formula_iupac          '(C15 H24 N7)2 [Fe2 Cl6 O]'
_chemical_formula_moiety         '2(C15 H24 N7 +), Cl6 Fe2 O 2-'
_chemical_formula_sum            'C30 H48 Cl6 Fe2 N14 O'
_chemical_formula_weight         945.22
_chemical_name_systematic
;
bis{2,6-bis[(1,3-dimethylimidazolin-2-ylidene)amino]pyridinium}
\m-oxido-bis[trichloridoiron(III)]
;
_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   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 99.438(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   10.5673(8)
_cell_length_b                   10.9286(8)
_cell_length_c                   18.3329(14)
_cell_measurement_reflns_used    1781
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      28.27
_cell_measurement_theta_min      2.18
_cell_volume                     2088.5(3)
_computing_cell_refinement       'SAINT (Bruker, 2002)'
_computing_data_collection       'SMART (Bruker, 2002)'
_computing_data_reduction        'SAINT (Bruker, 2002)'
_computing_molecular_graphics    'SHELXL97 (Sheldrick, 2008)'
_computing_publication_material  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      120(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker SMART APEX'
_diffrn_measurement_method       '\f and \w'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0664
_diffrn_reflns_av_sigmaI/netI    0.0511
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            20962
_diffrn_reflns_theta_full        28.20
_diffrn_reflns_theta_max         28.20
_diffrn_reflns_theta_min         1.95
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  430
_diffrn_standards_number         3795
_exptl_absorpt_coefficient_mu    1.123
_exptl_absorpt_correction_T_max  0.8065
_exptl_absorpt_correction_T_min  0.6437
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 2004)'
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.503
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             976
_exptl_crystal_size_max          0.43
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.962
_refine_diff_density_min         -0.716
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.985
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     249
_refine_ls_number_reflns         5142
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.985
_refine_ls_R_factor_all          0.0580
_refine_ls_R_factor_gt           0.0445
_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^)+(0.0646P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1071
_refine_ls_wR_factor_ref         0.1131
_reflns_number_gt                3929
_reflns_number_total             5142
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            em3010.cif
_cod_data_source_block           II
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2016582
_cod_database_fobs_code          2016582