Pyridine-imide oligomers.
Li, Xiao; Zhan, Chuanlang; Wang, Yaobing; Yao, Jiannian; Chemical communications (Cambridge, England)  (2008) 2444–2446; doi:10.1039/b800020d

data_7103138
_publ_section_title
;
 Pyridine-imide oligomers.
;
_journal_issue                   21
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              2444
_journal_page_last               2446
_journal_paper_doi               10.1039/b800020d
_journal_year                    2008
_chemical_absolute_configuration unk
_chemical_formula_moiety         'C25 H21 N5 O8'
_chemical_formula_sum            'C25 H21 N5 O8'
_chemical_formula_weight         519.47
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.7201(14)
_cell_length_b                   8.3506(15)
_cell_length_c                   37.025(7)
_cell_measurement_reflns_used    5605
_cell_measurement_temperature    113(2)
_cell_measurement_theta_max      27.9
_cell_measurement_theta_min      2.4
_cell_volume                     2386.9(7)
_computing_cell_refinement       CrystalClear
_computing_data_collection       CrystalClear
_computing_data_reduction        CrystalClear
_computing_publication_material  'CrystalStructure 3.7.0'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      113(2)
_diffrn_detector_area_resol_mean 7.31
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Rigaku Saturn'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  confocal
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71070
_diffrn_reflns_av_R_equivalents  0.0319
_diffrn_reflns_av_sigmaI/netI    0.0203
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       48
_diffrn_reflns_limit_l_min       -48
_diffrn_reflns_number            21235
_diffrn_reflns_theta_full        27.87
_diffrn_reflns_theta_max         27.87
_diffrn_reflns_theta_min         2.50
_exptl_absorpt_coefficient_mu    0.110
_exptl_absorpt_correction_T_max  0.9783
_exptl_absorpt_correction_T_min  0.9783
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Jacobson, R. (1998) Private communication'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.446
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1080
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.214
_refine_diff_density_min         -0.151
_refine_diff_density_rms         0.034
_refine_ls_abs_structure_details 'None, Friedel Pairs merged'
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.037
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     354
_refine_ls_number_reflns         3244
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.037
_refine_ls_R_factor_all          0.0327
_refine_ls_R_factor_gt           0.0312
_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^)+(0.0401P)^2^+0.4487P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0738
_refine_ls_wR_factor_ref         0.0750
_reflns_number_gt                3134
_reflns_number_total             3244
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b800020d.txt
_cod_data_source_block           shelxl
_cod_database_code               7103138