Multiple hydrogen bonds and tautomerism in naphthyridine derivatives
Carmen Alvarez-Rua; Santiago García-Granda; Shyamaprosad Goswami; Reshmi Mukherjee; Swapan Dey; Rosa M. Claramunt; M. Dolores Santa María; Isabel Rozas; Nadine Jagerovic; Ibon Alkorta; José Elguero; New J. Chem. 28 (2004) 700–707; doi:10.1039/b315692c

data_7050272
_publ_section_title
;
 Multiple hydrogen bonds and tautomerism in naphthyridine derivatives
;
_journal_issue                   6
_journal_name_full               'New J. Chem.'
_journal_page_first              700
_journal_page_last               707
_journal_paper_doi               10.1039/b315692c
_journal_volume                  28
_journal_year                    2004
_chemical_compound_source        synthesis
_chemical_formula_moiety         '2(C12 H12 N4 O2), H2 O'
_chemical_formula_sum            'C24 H26 N8 O5'
_chemical_formula_weight         506.53
_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                 93.915(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   27.8630(5)
_cell_length_b                   11.4857(2)
_cell_length_c                   7.5182(1)
_cell_measurement_reflns_used    18703
_cell_measurement_temperature    200(2)
_cell_measurement_theta_max      70.076
_cell_measurement_theta_min      1.767
_cell_volume                     2400.41(7)
_computing_cell_refinement       'HKL SCALEPACK (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Nonius BV, 1997-2000)'
_computing_data_reduction
'HKL DENZO and SCALEPACK (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'PLATON (Spek, 2001)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      200(2)
_diffrn_detector_area_resol_mean 9
_diffrn_measured_fraction_theta_full 0.938
_diffrn_measured_fraction_theta_max 0.938
_diffrn_measurement_device       '95mm CCD camera on \k-goniostat'
_diffrn_measurement_device_type  KappaCCD
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  'horizontally mounted graphite crystal'
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.5418
_diffrn_reflns_av_R_equivalents  0.0660
_diffrn_reflns_av_sigmaI/netI    0.1038
_diffrn_reflns_limit_h_max       33
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            26311
_diffrn_reflns_theta_full        69.85
_diffrn_reflns_theta_max         69.85
_diffrn_reflns_theta_min         3.18
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.846
_exptl_absorpt_correction_T_max  0.955
_exptl_absorpt_correction_T_min  0.860
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Sortav (Blessing, 1995) '
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.402
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1064
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.272
_refine_diff_density_min         -0.292
_refine_diff_density_rms         0.07
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.962
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     391
_refine_ls_number_reflns         4481
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.962
_refine_ls_R_factor_all          0.0697
_refine_ls_R_factor_gt           0.0461
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0809P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1221
_refine_ls_wR_factor_ref         0.1647
_reflns_number_gt                2970
_reflns_number_total             4481
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b315692c.txt
_cod_data_source_block           4a
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               7050272