A bicyclic unit reversal to stabilize the 12/14-helix in mixed homochiral oligoureas.
Milbeo, Pierre; Simon, Matthieu; Didierjean, Claude; Wenger, Emmanuel; Aubert, Emmanuel; Martinez, Jean; Amblard, Muriel; Calmès, Monique; Legrand, Baptiste; Chemical communications (Cambridge, England) 56 (2020) 7921–7924; doi:10.1039/d0cc02902e

data_7126622
_publ_section_title
;
 A bicyclic unit reversal to stabilize the 12/14-helix in mixed homochiral
 oligoureas.
;
_journal_issue                   57
_journal_name_full
'Chemical communications (Cambridge, England)'
_journal_page_first              7921
_journal_page_last               7924
_journal_paper_doi               10.1039/d0cc02902e
_journal_volume                  56
_journal_year                    2020
_chemical_absolute_configuration syn
_chemical_formula_moiety         'C81 H113 Br N18 O11'
_chemical_formula_sum            'C81 H113 Br N19 O10'
_chemical_formula_weight         1592.81
_space_group_crystal_system      tetragonal
_space_group_IT_number           78
_space_group_name_Hall           'P 4cw'
_space_group_name_H-M_alt        'P 43'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2018-11-27
_audit_creation_method
;
Olex2 1.2
(compiled 2018.05.29 svn.r3508 for OlexSys, GUI svn.r5506)
;
_audit_update_record
;
2020-02-07 deposited with the CCDC.	2020-05-27 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   11.7593(3)
_cell_length_b                   11.7593(3)
_cell_length_c                   63.070(3)
_cell_measurement_reflns_used    18292
_cell_measurement_temperature    114.6(3)
_cell_measurement_theta_max      75.9850
_cell_measurement_theta_min      3.7790
_cell_volume                     8721.4(5)
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_diffrn_ambient_temperature      114.6(3)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at zero, Atlas'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0640
_diffrn_reflns_av_unetI/netI     0.0659
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.991
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       54
_diffrn_reflns_limit_l_min       -79
_diffrn_reflns_number            42420
_diffrn_reflns_point_group_measured_fraction_full 0.839
_diffrn_reflns_point_group_measured_fraction_max 0.810
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         76.685
_diffrn_reflns_theta_min         3.759
_exptl_absorpt_coefficient_mu    1.169
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.407
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.38.46 (Rigaku Oxford Diffraction, 2015)
Numerical absorption correction based on gaussian integration over
			a multifaceted crystal model
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.213
_exptl_crystal_description       block
_exptl_crystal_F_000             3388
_exptl_crystal_size_max          0.421
_exptl_crystal_size_mid          0.354
_exptl_crystal_size_min          0.112
_refine_diff_density_max         1.109
_refine_diff_density_min         -0.635
_refine_diff_density_rms         0.089
_refine_ls_abs_structure_details
;
 Classical Flack method preferred over Parsons because s.u. lower.
;
_refine_ls_abs_structure_Flack   -0.02(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.086
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1002
_refine_ls_number_reflns         14853
_refine_ls_number_restraints     196
_refine_ls_restrained_S_all      1.080
_refine_ls_R_factor_all          0.1129
_refine_ls_R_factor_gt           0.0986
_refine_ls_shift/su_max          0.007
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+86.2825P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2401
_refine_ls_wR_factor_ref         0.2471
_reflns_Friedel_coverage         0.620
_reflns_Friedel_fraction_full    0.675
_reflns_Friedel_fraction_max     0.626
_reflns_number_gt                13770
_reflns_number_total             14853
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d0cc02902e2.cif
_cod_data_source_block           Cpd4-pm04-91
_cod_depositor_comments
'Adding full bibliography for 7126621--7126622.cif.'
_cod_original_cell_volume        8721.4(6)
_cod_database_code               7126622
_shelx_shelxl_version_number     2018/3
_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. Rigid bond restraints
 CB_2, CG_2, CD2_2, CD1_2, CE2_2, CE1_2, CZ_2
 with sigma for 1-2 distances of 0.005 and sigma for 1-3 distances of 0.005
 CB_6, CG_6, CD2_6, CD1_6, CE2_6, CE1_6, CZ_6
 with sigma for 1-2 distances of 0.005 and sigma for 1-3 distances of 0.005
 C_10, O_10, O_11, C1_11, C2_11, C3_11, C4_11, C5_11, C6_11, C7_11
 with sigma for 1-2 distances of 0.005 and sigma for 1-3 distances of 0.005
3. Uiso/Uaniso restraints and constraints
CB_2 \\sim CG_2 \\sim CD2_2 \\sim CD1_2 \\sim CE2_2 \\sim CE1_2 \\sim CZ_2:
within 2A with sigma of 0.04 and sigma for terminal atoms of 0.08
CB_6 \\sim CG_6 \\sim CD2_6 \\sim CD1_6 \\sim CE2_6 \\sim CE1_6 \\sim CZ_6:
within 2A with sigma of 0.04 and sigma for terminal atoms of 0.08
C_10 \\sim O_10 \\sim O_11 \\sim C1_11 \\sim C2_11 \\sim C3_11 \\sim C4_11
\\sim C5_11 \\sim C6_11 \\sim C7_11: within 2A with sigma of 0.04 and sigma for
terminal atoms of 0.08
4.a Ternary CH refined with riding coordinates:
 CA(HA), CA(HA), CG1(HG1), CA(HA), CA(HA), CG1(HG1), CA(HA), CA(HA), CG1(HG1),
 CA(HA), CA(HA), CG1(HG1)
4.b Secondary CH2 refined with riding coordinates:
 CBB(HBBA,HBBB), CB(HBA,HBB), CB1(HB1A,HB1B), CB2(HB2A,HB2B), CG2(HG2A,HG2B),
 CB3(HB3A,HB3B), CG3(HG3A,HG3B), CBB(HBBA,HBBB), CB1(HB1A,HB1B), CB2(HB2A,HB2B),
  CG2(HG2A,HG2B), CB3(HB3A,HB3B), CG3(HG3A,HG3B), CBB(HBBA,HBBB), CB(HBA,HBB),
 CB1(HB1A,HB1B), CB2(HB2A,HB2B), CG2(HG2A,HG2B), CB3(HB3A,HB3B), CG3(HG3A,HG3B),
  CBB(HBBA,HBBB), CB1(HB1A,HB1B), CB2(HB2A,HB2B), CG2(HG2A,HG2B), CB3(HB3A,
 HB3B), CG3(HG3A,HG3B), CA(HAA,HAB), CB(HBA,HBB), C1(H1A,H1B)
4.c Aromatic/amide H refined with riding coordinates:
 C2(H2), C3(H3), C5(H5), C6(H6), N1(H1), N(H), N1(H1), CD1(HD1), CE1(HE1),
 CZ(HZ), CE2(HE2), CD2(HD2), N(H), N1(H1), N(H), N1(H1), N(H), N1(H1), N(H),
 N1(H1), CD1(HD1), CE1(HE1), CZ(HZ), CE2(HE2), CD2(HD2), N(H), N1(H1), N(H),
 N1(H1), N(H), N1(H1), N(H), C3(H3), C4(H4), C5(H5), C6(H6), C7(H7)
4.d Idealised Me refined as rotating group:
 CB(HBA,HBB,HBC), CB(HBA,HBB,HBC)
;
_shelx_res_checksum              84056
_shelx_fab_checksum              75291
_olex2_submission_special_instructions 'No special instructions were received'