Helical peptaibol mimics are better ionophores when racemic than when enantiopure.
Pike, Sarah J.; Jones, Jennifer E.; Raftery, James; Clayden, Jonathan; Webb, Simon J.; Organic & biomolecular chemistry 13 (2015) 9580–9584; doi:10.1039/c5ob01652e

data_7154657
_publ_section_title
;
 Helical peptaibol mimics are better ionophores when racemic than when
 enantiopure.
;
_journal_issue                   37
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              9580
_journal_page_last               9584
_journal_paper_doi               10.1039/c5ob01652e
_journal_volume                  13
_journal_year                    2015
_chemical_formula_sum            'C34 H55 N5 O8'
_chemical_formula_weight         661.83
_chemical_melting_point          488.5(5)
_chemical_name_common            Cbz-(rac)-(\aMe)ValAib4OtBu
_chemical_name_systematic        'racemic CbzMeValAib4OtBu'
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_audit_update_record
;
2015-04-30 deposited with the CCDC.
2015-08-21 downloaded from the CCDC.
;
_cell_angle_alpha                96.466(5)
_cell_angle_beta                 102.806(4)
_cell_angle_gamma                90.975(4)
_cell_formula_units_Z            2
_cell_length_a                   11.4534(8)
_cell_length_b                   11.6801(9)
_cell_length_c                   14.4308(11)
_cell_measurement_reflns_used    5705
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      70.08
_cell_measurement_theta_min      3.81
_cell_volume                     1868.8(2)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.954
_diffrn_measured_fraction_theta_max 0.946
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0392
_diffrn_reflns_av_sigmaI/netI    0.0560
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            14758
_diffrn_reflns_theta_full        67.00
_diffrn_reflns_theta_max         70.15
_diffrn_reflns_theta_min         3.16
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.684
_exptl_absorpt_correction_T_max  0.9537
_exptl_absorpt_correction_T_min  0.75506
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            violet
_exptl_crystal_density_diffrn    1.176
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             716
_exptl_crystal_recrystallization_method 'Re-crystallisation from solvent: '
_exptl_crystal_size_max          0.29
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.07
_refine_diff_density_max         0.368
_refine_diff_density_min         -0.425
_refine_diff_density_rms         0.050
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.090
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     472
_refine_ls_number_reflns         6723
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.089
_refine_ls_R_factor_all          0.0631
_refine_ls_R_factor_gt           0.0524
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0722P)^2^+0.6805P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1417
_refine_ls_wR_factor_ref         0.1505
_reflns_number_gt                5516
_reflns_number_total             6723
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c5ob01652e2.cif
_cod_data_source_block           s4023ma
_cod_depositor_comments
;
The following automatic conversions were performed:

'_chemical_melting_point' value '488-489 ' was changed to '488.5(5)'
- the average value was taken and precision was estimated.

'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
according to
/usr/data/users/saulius/crontab/automatic-downloads/rss-feeds/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 3271 2015-04-21 07:52:19Z andrius 

 Adding full bibliography for 7154657.cif.
;
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7154657