12/10-Helical β-Peptide with Dynamic Folding Propensity: Coexistence of Right- and Left-Handed Helices in an Enantiomeric Foldamer.
Shin, Seonho; Lee, Mihye; Guzei, Ilia A.; Kang, Young Kee; Choi, Soo Hyuk; Journal of the American Chemical Society 138 (2016) 13390–13395; doi:10.1021/jacs.6b08235

data_4130970
_publ_section_title
;
 12/10-Helical \b-Peptide with Dynamic Folding Propensity: Coexistence of
 Right- and Left-Handed Helices in an Enantiomeric Foldamer.
;
_journal_issue                   40
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              13390
_journal_page_last               13395
_journal_paper_doi               10.1021/jacs.6b08235
_journal_volume                  138
_journal_year                    2016
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C41 H68 N6 O7'
_chemical_formula_sum            'C44.5 H76.5 N6 O7'
_chemical_formula_weight         807.61
_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   mixed
_atom_sites_solution_primary     direct
_audit_creation_date             2015-02-23
_audit_creation_method
;
Olex2 1.2-dev
(compiled 2015.02.20 svn.r3157 for OlexSys, GUI svn.r5013)
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.727(2)
_cell_length_b                   17.750(3)
_cell_length_c                   25.980(3)
_cell_measurement_temperature    100(2)
_cell_volume                     4485.6(13)
_computing_molecular_graphics    'OLEX2 (Dolomanov et al., 2009)'
_computing_publication_material  'OLEX2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'XL (Sheldrick, 2015b)'
_computing_structure_solution    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      100.0
_diffrn_detector_type            'CCD area detector'
_diffrn_measured_fraction_theta_full 0.979
_diffrn_measured_fraction_theta_max 0.967
_diffrn_measurement_device       'three-circle diffractometer'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0755
_diffrn_reflns_av_unetI/netI     0.0395
_diffrn_reflns_Laue_measured_fraction_full 0.979
_diffrn_reflns_Laue_measured_fraction_max 0.967
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       31
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            70433
_diffrn_reflns_point_group_measured_fraction_full 0.980
_diffrn_reflns_point_group_measured_fraction_max 0.964
_diffrn_reflns_theta_full        67.000
_diffrn_reflns_theta_max         73.714
_diffrn_reflns_theta_min         3.015
_exptl_absorpt_coefficient_mu    0.644
_exptl_absorpt_correction_T_max  0.8894
_exptl_absorpt_correction_T_min  0.8211
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.196
_exptl_crystal_description       block
_exptl_crystal_F_000             1766
_exptl_crystal_size_max          0.254
_exptl_crystal_size_mid          0.104
_exptl_crystal_size_min          0.054
_refine_diff_density_max         0.190
_refine_diff_density_min         -0.171
_refine_diff_density_rms         0.034
_refine_ls_abs_structure_details
;
 Flack x determined using 3024 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.10(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.030
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     510
_refine_ls_number_reflns         8738
_refine_ls_number_restraints     6
_refine_ls_restrained_S_all      1.030
_refine_ls_R_factor_all          0.0458
_refine_ls_R_factor_gt           0.0361
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0394P)^2^+0.4157P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0782
_refine_ls_wR_factor_ref         0.0821
_reflns_Friedel_coverage         0.787
_reflns_Friedel_fraction_full    0.981
_reflns_Friedel_fraction_max     0.961
_reflns_number_gt                7603
_reflns_number_total             8738
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja6b08235_si_001.cif
_cod_data_source_block           choi13_sq
_cod_original_cell_volume        4485.6(14)
_cod_original_formula_sum        'C44.50 H76.50 N6 O7'
_cod_database_code               4130970
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups, All N(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Restrained distances
 N1-H1 = N2-H2 = N3-H3 = N4-H4 = N5-H5 = N6-H6
 0.8395 with sigma of 0.002
3.a Ternary CH refined with riding coordinates:
 C6(H6A), C11(H11), C13(H13), C18(H18), C20(H20), C25(H25), C27(H27), C32(H32),
  C34(H34), C39(H39)
3.b Secondary CH2 refined with riding coordinates:
 C7(H7A,H7B), C8(H8A,H8B), C9(H9A,H9B), C10(H10A,H10B), C14(H14A,H14B),
 C15(H15A,H15B), C16(H16A,H16B), C17(H17A,H17B), C21(H21A,H21B), C22(H22A,H22B),
  C23(H23A,H23B), C24(H24A,H24B), C28(H28A,H28B), C29(H29A,H29B), C30(H30A,
 H30B), C31(H31A,H31B), C35(H35A,H35B), C36(H36A,H36B), C37(H37A,H37B),
 C38(H38A,H38B)
3.c Idealised Me refined as rotating group:
 C1(H1A,H1B,H1C), C2(H2A,H2B,H2C), C3(H3A,H3B,H3C), C41(H41A,H41B,H41C)
;
_shelx_res_checksum              51787
_shelx_hkl_checksum              19242
_shelx_fab_checksum              97508
_shelx_shelxl_version_number     2014/7
_olex2_submission_special_instructions 'No special instructions were received'