Helix-Forming Propensity of Aliphatic Urea Oligomers Incorporating Noncanonical Residue Substitution Patterns
Nagendar Pendem; Céline Douat; Paul Claudon; Michel Laguerre; Sabine Castano; Bernard Desbat; Dominique Cavagnat; Eric Ennifar; Brice Kauffmann; Gilles Guichard; Journal of the American Chemical Society 135 (2013) 4884–4892; doi:10.1021/ja401151v

data_4119517
_publ_section_title
;
 Helix-Forming Propensity of Aliphatic Urea Oligomers Incorporating
 Noncanonical Residue Substitution Patterns
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              4884
_journal_page_last               4892
_journal_paper_doi               10.1021/ja401151v
_journal_volume                  135
_journal_year                    2013
_chemical_absolute_configuration ad
_chemical_formula_sum            'C88 H160 N32 O16'
_chemical_formula_weight         1922.48
_space_group_IT_number           92
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'P 4abw 2nw'
_symmetry_space_group_name_H-M   'P 41 21 2'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            1
_cell_length_a                   11.949
_cell_length_b                   11.949
_cell_length_c                   18.656
_cell_measurement_temperature    213(2)
_cell_volume                     2663.678
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXD (Sheldrick, 2008)'
_diffrn_ambient_temperature      213(2)
_diffrn_measured_fraction_theta_full 0.985
_diffrn_measured_fraction_theta_max 0.986
_diffrn_radiation_monochromator  'osmic mirrors'
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0625
_diffrn_reflns_av_sigmaI/netI    0.0456
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            31576
_diffrn_reflns_theta_full        72.51
_diffrn_reflns_theta_max         72.51
_diffrn_reflns_theta_min         4.39
_exptl_absorpt_coefficient_mu    0.691
_exptl_absorpt_correction_type   none
_exptl_crystal_density_diffrn    1.198
_exptl_crystal_F_000             1040
_exptl_crystal_size_max          0.1
_exptl_crystal_size_mid          0.1
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.364
_refine_diff_density_min         -0.412
_refine_diff_density_rms         0.101
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.3(3)
_refine_ls_extinction_coef       0.0000
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.042
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     165
_refine_ls_number_reflns         2589
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.042
_refine_ls_R_factor_all          0.0909
_refine_ls_R_factor_gt           0.0594
_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^)+(0.1107P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1368
_refine_ls_wR_factor_ref         0.1695
_reflns_number_gt                1858
_reflns_number_total             2589
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja401151v_si_006.cif
_cod_data_source_block           pn137
_cod_original_cell_volume        2663.8
_cod_database_code               4119517