[(1-Methylcytosine)~2~H]I, an asymmetric base pair
Jens Müller; Eva Freisinger; Acta Crystallographica Section E 61 (2005) o320–o322; doi:10.1107/S1600536805000693

data_2205116
_publ_section_title
;
 [(1-Methylcytosine)~2~H]I, an asymmetric base pair
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o320
_journal_page_last               o322
_journal_paper_doi               10.1107/S1600536805000693
_journal_volume                  61
_journal_year                    2005
_chemical_formula_iupac          'C5 H8 N3 O +, I -, C5 H7 N3 O'
_chemical_formula_moiety         'C5 H8 N3 O +, I -, C5 H7 N3 O'
_chemical_formula_sum            'C10 H15 I N6 O2'
_chemical_formula_weight         378.18
_chemical_name_common            'hemiprotonated 1-methylcytosine'
_chemical_name_systematic
;
1-Methylcytosinium iodide 1-methylcytosine
;
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_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                 97.59(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   7.1950(10)
_cell_length_b                   8.629(2)
_cell_length_c                   11.522(2)
_cell_measurement_reflns_used    4452
_cell_measurement_temperature    163(2)
_cell_measurement_theta_max      25.35
_cell_measurement_theta_min      2.86
_cell_volume                     709.1(2)
_computing_cell_refinement
'DENZO and SCALEPACK (Otwinowski & Minor, 1997)'
_computing_data_collection       'KappaCCD Software (Nonius, 1998)'
_computing_data_reduction        'DENZO and SCALEPACK'
_computing_molecular_graphics    'SHELXTL-PLUS (VMS) (Sheldrick, 1990b)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1990a)'
_diffrn_ambient_temperature      163(2)
_diffrn_detector_area_resol_mean 44
_diffrn_measured_fraction_theta_full 0.969
_diffrn_measured_fraction_theta_max 0.969
_diffrn_measurement_device       'Nonius KappaCCD'
_diffrn_measurement_method
;
360 frames via \w-rotation (\D\w\=1\%) and two times 5s per frame
;
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0216
_diffrn_reflns_av_sigmaI/netI    0.0402
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            4435
_diffrn_reflns_theta_full        25.35
_diffrn_reflns_theta_max         25.35
_diffrn_reflns_theta_min         2.86
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    2.267
_exptl_absorpt_correction_T_max  0.4274
_exptl_absorpt_correction_T_min  0.3583
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SCALEPACK; Otwinowski & Minor, 1997)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.771
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             372
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.38
_refine_diff_density_max         0.311
_refine_diff_density_min         -0.266
_refine_ls_abs_structure_details 'Flack (1983), 1166 Friedel pairs'
_refine_ls_abs_structure_Flack   0.52(2)
_refine_ls_extinction_coef       0.0174(9)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   0.980
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     183
_refine_ls_number_reflns         2519
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.980
_refine_ls_R_factor_all          0.0247
_refine_ls_R_factor_gt           0.0204
_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/[\s^2^(Fo^2^)+(0.0118P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0421
_refine_ls_wR_factor_ref         0.0429
_reflns_number_gt                2291
_reflns_number_total             2519
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            lh6348.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               2205116
_cod_database_fobs_code          2205116