Crystal Engineering of Hand-Twisted Helical Crystals.
Saha, Subhankar; Desiraju, Gautam R.; Journal of the American Chemical Society 139 (2017) 1975–1983; doi:10.1021/jacs.6b11835

data_4125707
_publ_section_title
;
 Crystal Engineering of Hand-Twisted Helical Crystals.
;
_journal_issue                   5
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              1975
_journal_page_last               1983
_journal_paper_doi               10.1021/jacs.6b11835
_journal_volume                  139
_journal_year                    2017
_chemical_formula_sum            'C14 H10 Br N O4'
_chemical_formula_weight         336.14
_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                   3.843(3)
_cell_length_b                   12.597(8)
_cell_length_c                   27.201(18)
_cell_measurement_reflns_used    4780
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      33.7
_cell_measurement_theta_min      3.0
_cell_volume                     1316.8(16)
_computing_cell_refinement
;
CrystalClear-SM Expert 2.0 rc14 (Rigaku, 2009)
;
_computing_data_collection
;
CrystalClear-SM Expert 2.0 rc14 (Rigaku, 2009)
;
_computing_data_reduction
;
CrystalClear-SM Expert 2.0 rc14 (Rigaku, 2009)
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXL-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      150(2)
_diffrn_detector_area_resol_mean 13.6612
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device
;
XtaLABmini: Fixed Chi 2 circle
;
_diffrn_measurement_device_type
;
Rigaku Mercury375R (2x2 bin mode)
;
_diffrn_measurement_method       'profile data from \w-scans'
_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  0.1292
_diffrn_reflns_av_sigmaI/netI    0.0705
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       33
_diffrn_reflns_limit_l_min       -33
_diffrn_reflns_number            12007
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         1.50
_exptl_absorpt_coefficient_mu    3.134
_exptl_absorpt_correction_T_max  0.7243
_exptl_absorpt_correction_T_min  0.5456
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Jacobson, R. (1998) Private communication'
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.696
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Needle
_exptl_crystal_F_000             672
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.11
_exptl_crystal_size_min          0.11
_refine_diff_density_max         0.631
_refine_diff_density_min         -1.120
_refine_diff_density_rms         0.198
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.031(16)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.198
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     182
_refine_ls_number_reflns         2591
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.198
_refine_ls_R_factor_all          0.0446
_refine_ls_R_factor_gt           0.0412
_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^)+(0.0744P)^2^+0.0785P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1061
_refine_ls_wR_factor_ref         0.1393
_reflns_number_gt                2510
_reflns_number_total             2591
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            ja6b11835_si_004.cif
_cod_data_source_block           4c
_cod_original_cell_volume        1316.8(15)
_cod_original_sg_symbol_H-M      P212121
_cod_database_code               4125707