Homogeneous and Robust Polyproline Type I Helices from Peptoids with Nonaromatic α-Chiral Side Chains.
Roy, Olivier; Dumonteil, Geoffrey; Faure, Sophie; Jouffret, Laurent; Kriznik, Alexandre; Taillefumier, Claude; Journal of the American Chemical Society 139 (2017) 13533–13540; doi:10.1021/jacs.7b07475

data_4131606
_publ_section_title
;
 Homogeneous and Robust Polyproline Type I Helices from Peptoids with
 Nonaromatic \a-Chiral Side Chains.
;
_journal_issue                   38
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              13533
_journal_page_last               13540
_journal_paper_doi               10.1021/jacs.7b07475
_journal_volume                  139
_journal_year                    2017
_chemical_formula_sum            'C269.5 H521.4 N32 O47.17'
_chemical_formula_weight         4965.28
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90.00(3)
_cell_angle_beta                 90.00(3)
_cell_angle_gamma                90.00(3)
_cell_formula_units_Z            1
_cell_length_a                   17.686(4)
_cell_length_b                   19.331(4)
_cell_length_c                   23.621(5)
_cell_measurement_temperature    100(2)
_cell_volume                     8076(3)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.953
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0545
_diffrn_reflns_av_unetI/netI     0.0302
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.953
_diffrn_reflns_limit_h_max       26
_diffrn_reflns_limit_h_min       -26
_diffrn_reflns_limit_k_max       29
_diffrn_reflns_limit_k_min       -28
_diffrn_reflns_limit_l_max       35
_diffrn_reflns_limit_l_min       -35
_diffrn_reflns_number            651465
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.934
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         33.327
_diffrn_reflns_theta_min         2.021
_exptl_absorpt_coefficient_mu    0.069
_exptl_crystal_density_diffrn    1.021
_exptl_crystal_F_000             2740
_refine_diff_density_max         2.289
_refine_diff_density_min         -0.845
_refine_diff_density_rms         0.106
_refine_ls_abs_structure_details
;
 Flack x determined using 9722 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.06(8)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.050
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     824
_refine_ls_number_reflns         29174
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.050
_refine_ls_R_factor_all          0.1004
_refine_ls_R_factor_gt           0.0787
_refine_ls_shift/su_max          2.771
_refine_ls_shift/su_mean         0.021
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1455P)^2^+4.0453P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2156
_refine_ls_wR_factor_ref         0.2352
_reflns_Friedel_coverage         0.829
_reflns_Friedel_fraction_full    0.999
_reflns_Friedel_fraction_max     0.912
_reflns_number_gt                23947
_reflns_number_total             29174
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja7b07475_si_003.cif
_cod_data_source_block           OR418_JUIN2017_a
_cod_original_formula_sum        'C269.50 H521.40 N32 O47.17'
_cod_database_code               4131606
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              51792
_shelx_hkl_checksum              85260