Helix Formation in Preorganized β/γ-Peptide Foldamers: Hydrogen-Bond Analogy to the α-Helix without α-Amino Acid Residues
Li Guo; Aaron M. Almeida; Weicheng Zhang; Andrew G. Reidenbach; Soo Hyuk Choi; Ilia A. Guzei; Samuel H. Gellman; Journal of the American Chemical Society 132 (2010) 7868–7869; doi:10.1021/ja103233a

data_4102536
_publ_contact_author_address
;
Department of Chemistry
University of Wisconsin-Madison
1101 University Ave
Madison, WI  53706
USA
;
_publ_contact_author_email       iguzei@chem.wisc.edu
_publ_contact_author_fax         608-262-0381
_publ_contact_author_name
;
Guzei, Ilia A. 
;
_publ_contact_author_phone       608-263-4694
_publ_section_title
;
 Helix Formation in Preorganized \b/\g-Peptide Foldamers: Hydrogen-Bond
 Analogy to the \a-Helix without \a-Amino Acid Residues
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              7868
_journal_page_last               7869
_journal_paper_doi               10.1021/ja103233a
_journal_volume                  132
_journal_year                    2010
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C44 H68 N4 O7, 0.61(C H Cl3)'
_chemical_formula_sum            'C44.61 H68.61 Cl1.83 N4 O7'
_chemical_formula_weight         837.84
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_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
;
manual editing of the CIF file 
created by SHELXTL Ver. 6.10
and processed with modiCIfer-03272007. 
;
_audit_update_record
;
2009-08-07 # Formatted by publCIF
;
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   16.5029(4)
_cell_length_b                   20.8999(5)
_cell_length_c                   30.0805(7)
_cell_measurement_reflns_used    9704
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      69.62
_cell_measurement_theta_min      2.57
_cell_volume                     10375.0(4)
_computing_cell_refinement       'SAINT Ver. 7.24A (Bruker-AXS, 2007)'
_computing_data_collection       'APEX2 Ver. 2.1-4 (Bruker-AXS, 2007)'
_computing_data_reduction        'SAINT Ver. 7.24A'
_computing_molecular_graphics    SHELXTL
_computing_publication_material  SHELXTL
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Sheldrick, 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'Bruker SMART APEX2 area detector'
_diffrn_measurement_method       '0.50\% \w and 0.5 \% \f scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           Cu-K\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0521
_diffrn_reflns_av_sigmaI/netI    0.0341
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       25
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       36
_diffrn_reflns_limit_l_min       -35
_diffrn_reflns_number            133008
_diffrn_reflns_theta_full        67.00
_diffrn_reflns_theta_max         69.62
_diffrn_reflns_theta_min         2.57
_exptl_absorpt_coefficient_mu    1.411
_exptl_absorpt_correction_T_max  0.9089
_exptl_absorpt_correction_T_min  0.5914
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS  (Bruker-AXS, 2007)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.073
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             3611
_exptl_crystal_size_max          0.42
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.07
_platon_squeeze_details
;
The volume occupied by solvent is  0.0 percent of the unit cell.
;
_refine_diff_density_max         0.688
_refine_diff_density_min         -0.261
_refine_diff_density_rms         0.048
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.033(17)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.978
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1083
_refine_ls_number_reflns         19287
_refine_ls_number_restraints     50
_refine_ls_restrained_S_all      0.985
_refine_ls_R_factor_all          0.0630
_refine_ls_R_factor_gt           0.0511
_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^)+(0.1017P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1353
_refine_ls_wR_factor_ref         0.1436
_reflns_number_gt                15714
_reflns_number_total             19287
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ja103233a_si_002.cif
_cod_data_source_block           gellman119
_cod_original_sg_symbol_Hall     'P 2ac 2ab   '
_cod_original_sg_symbol_H-M      'P 21 21 21 '
_cod_database_code               4102536