A homochiral triple helix constructed from an axially chiral bipyridine
Wenbin Lin; Yong Cui; Helen L. Ngo; Chemical communications (Cambridge, England)  (2003) –; doi:10.1039/b212781d

data_7103687
_publ_section_title
;
A homochiral triple helix constructed from an
axially chiral bipyridine
;
_journal_name_full
'Chemical communications (Cambridge, England)'
_journal_paper_doi               10.1039/b212781d
_journal_year                    2003
_chemical_formula_sum            'C47.5 H50 N2 Ni O8.5'
_chemical_formula_weight         843.61
_chemical_name_systematic
; 
? 
;
_space_group_IT_number           5
_symmetry_space_group_name_Hall  'C 2y'
_symmetry_space_group_name_H-M   'C 1 2 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                 114.379(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   26.4314(7)
_cell_length_b                   11.4071(3)
_cell_length_c                   16.5957(4)
_cell_measurement_temperature    293(2)
_cell_volume                     4557.5(2)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0728
_diffrn_reflns_av_sigmaI/netI    0.0737
_diffrn_reflns_limit_h_max       31
_diffrn_reflns_limit_h_min       -31
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            15651
_diffrn_reflns_theta_full        25.05
_diffrn_reflns_theta_max         25.05
_diffrn_reflns_theta_min         1.35
_exptl_absorpt_coefficient_mu    0.479
_exptl_crystal_density_diffrn    1.229
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             1780
_refine_diff_density_max         0.894
_refine_diff_density_min         -0.388
_refine_diff_density_rms         0.090
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.02(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.062
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     520
_refine_ls_number_reflns         8043
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.067
_refine_ls_R_factor_all          0.0969
_refine_ls_R_factor_gt           0.0733
_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^)+(0.1076P)^2^+7.4282P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1847
_refine_ls_wR_factor_ref         0.2004
_reflns_number_gt                6327
_reflns_number_total             8043
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b212781d.txt
_cod_data_source_block           c02111m
_cod_original_formula_sum        'C47.50 H50 N2 Ni O8.50'
_cod_database_code               7103687