From bifunctional nucleophilic behavior of DBU to a new heterocyclic fluorescent platform.
Gryko, Daniel T.; Piechowska, Joanna; Tasior, Mariusz; Waluk, Jacek; Orzanowska, Grazyna; Organic letters 8 (2006) 4747–4750; doi:10.1021/ol061827m

data_1506208
_publ_section_title
;
 From bifunctional nucleophilic behavior of DBU to a new heterocyclic
 fluorescent platform.
;
_journal_issue                   21
_journal_name_full               'Organic letters'
_journal_page_first              4747
_journal_page_last               4750
_journal_paper_doi               10.1021/ol061827m
_journal_volume                  8
_journal_year                    2006
_chemical_formula_sum            'C17 H18 N4'
_chemical_formula_weight         278.35
_chemical_name_common            amino-pyrrolo[2,3-b]quinoxaline
_chemical_name_systematic
;
 1H-3a,8,13,13b-tetraazabenzo[b]cyclohepta[1,2,3-jk]fluorene
;
_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
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 95.83(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.4562(12)
_cell_length_b                   16.273(3)
_cell_length_c                   11.316(2)
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      24.06
_cell_measurement_theta_min      0.998
_cell_volume                     1365.9(5)
_computing_cell_refinement       'Denzo & Scalepak (Otwinowski, Minor, 1997)'
_computing_data_collection       'Collect (Nonius B.V. 1998)'
_computing_data_reduction        'Denzo & Scalepak (Otwinowski, Minor, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.992
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0507
_diffrn_reflns_av_sigmaI/netI    0.0823
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            3349
_diffrn_reflns_theta_full        22.46
_diffrn_reflns_theta_max         22.46
_diffrn_reflns_theta_min         2.20
_exptl_absorpt_coefficient_mu    0.084
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            brown
_exptl_crystal_density_diffrn    1.354
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             592
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.738
_refine_diff_density_min         -0.292
_refine_diff_density_rms         0.058
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.960
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     190
_refine_ls_number_reflns         1756
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.960
_refine_ls_R_factor_all          0.1374
_refine_ls_R_factor_gt           0.0691
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1130P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1690
_refine_ls_wR_factor_ref         0.1954
_reflns_number_gt                955
_reflns_number_total             1756
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ol061827msi20060904_103135.cif
_cod_data_source_block           shelxs97
_cod_original_cell_volume        1365.9
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               1506208