Structural and spectroscopic study of 6,7-dicyano-substituted lumazine with high electron affinity and proton acidity.
Sakai, Ken-ichi; Nagahara, Kenta; Yoshii, Yuuya; Hoshino, Norihisa; Akutagawa, Tomoyuki; The journal of physical chemistry. A 117 (2013) 3614–3624; doi:10.1021/jp401528c

data_1516017
_publ_section_title
;
 Structural and spectroscopic study of 6,7-dicyano-substituted lumazine
 with high electron affinity and proton acidity.
;
_journal_issue                   17
_journal_name_full               'The journal of physical chemistry. A'
_journal_page_first              3614
_journal_page_last               3624
_journal_paper_doi               10.1021/jp401528c
_journal_volume                  117
_journal_year                    2013
_chemical_formula_sum            'C8 H3.33333 N6 O2.66667'
_chemical_formula_weight         226.15
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.0000
_cell_angle_beta                 91.9071(8)
_cell_angle_gamma                90.0000
_cell_formula_units_Z            12
_cell_length_a                   5.59928(10)
_cell_length_b                   24.2233(5)
_cell_length_c                   19.9883(4)
_cell_measurement_reflns_used    4530
_cell_measurement_temperature    100
_cell_measurement_theta_max      68.14
_cell_measurement_theta_min      3.65
_cell_volume                     2709.57(9)
_computing_cell_refinement       'RAPID AUTO'
_computing_data_collection       'RAPID AUTO (Rigaku, ????)'
_computing_data_reduction        'RAPID AUTO'
_computing_molecular_graphics    'CrystalStructure 4.0'
_computing_publication_material  'CrystalStructure 4.0 (Rigaku, 2010)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      100
_diffrn_detector_area_resol_mean 10.000
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Rigaku R-AXIS RAPID'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54187
_diffrn_reflns_av_R_equivalents  0.0294
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       29
_diffrn_reflns_limit_k_min       -29
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            30504
_diffrn_reflns_theta_full        68.23
_diffrn_reflns_theta_max         68.23
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.140
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            brown
_exptl_crystal_density_diffrn    1.663
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       platelet
_exptl_crystal_F_000             1376.00
_exptl_crystal_size_max          0.200
_exptl_crystal_size_mid          0.100
_exptl_crystal_size_min          0.050
_refine_diff_density_max         0.250
_refine_diff_density_min         -0.360
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.003
_refine_ls_hydrogen_treatment    mixed
_refine_ls_number_parameters     467
_refine_ls_number_reflns         4950
_refine_ls_number_restraints     0
_refine_ls_R_factor_gt           0.0397
_refine_ls_shift/su_max          0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0681P)^2^+1.4091P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1121
_reflns_number_gt                4303
_reflns_number_total             4950
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
_cod_data_source_file            jp401528c_si_001.cif
_cod_data_source_block           DCNLH2
_cod_database_code               1516017